Tardigrades, the ubiquitous microscopic animals that resemble gummy bears with eight legs, are renowned for their ability to survive some of the harshest environmental conditions for decades without food and water.

These hardy animals can easily endure levels of radiation that would be lethal to most other forms of life, extreme temperatures and even survive in the vacuum of space. Some scientists think that uncovering the genes responsible for their remarkable resilience, particularly to ultrahigh radiation, could unlock a range of potential applications from cancer research to space exploration.

And we may be closer than ever to unlocking them. Chinese scientists have now identified a new species of tardigrades hosting thousands of genes that become more active when exposed to radiation. The findings point to a complex defense system that shields tardigrade DNA from radiation-induced damage and can pave the way for devising better protection for astronauts from the stresses of long-duration missions, researchers say.

The new species, named Hypsibius henanensis after China's Henan province where it was collected about six years ago, was pummeled with doses of radiation many times higher than what would be lethal for humans. The bombardment affected 2,801 tardigrade genes associated with DNA repair, cell division, hormone metabolism and immune responses, according to a paper published Oct. 25 in the journal Science.

Related: 1st tardigrade fossils ever discovered hint at how they survived Earth's biggest mass extinction

One of the genes that became most active, called DODA1, appears to resist radiation damage by enabling tardigrades to produce antioxidant pigments known as betalains, which can erase some of the harmful reactive chemicals inside cells that are caused by radiation. When the researchers treated human cells with a tardigrade's betalains, they found the cells fared much better at surviving radiation than untreated cells, study co-author Lingqiang Zhang, who is a molecular and cellular biologist at the Beijing Institute of Lifeomics, told Nature News.

Tardigrades, commonly known as water bears or moss piglets, have been the subject of extensive research due to their extraordinary resilience. In 2007, they became the first animals to survive exposure to outer space after a Russian crewless capsule ferried 3,000 living tardigrades on a European mission to low Earth orbit, and exposed them to the hard vacuum of space for 10 days. 68 percent of them survived and gave birth to normal offspring. The same occurred with tardigrades that were blasted to space in 2011 on the final flight of NASA's space shuttle Endeavour.

A few thousand tardigrades were spilled onto the moon's surface after riding there aboard Israel's Beresheet spacecraft, which crashed during landing. While the fact that the specimens lay dormant on lunar soil raised ethical questions, microbiologists have deemed their chances of colonizing the moon zero, given the lack of oxygen and liquid water.

Tardigrades' most recent trip to space was in 2021 to the International Space Station, where a long-term study of their genes and other survival techniques is underway.

"We want to see what 'tricks' they use to survive when they arrive in space, and, over time, what tricks their offspring use," Thomas Boothby, an associate professor of molecular biology at the University of Wyoming, said in a previous NASA statement. "Are they the same or do they change across generations? We just don't know what to expect."

Scientists know from previous research that tardigrades persist through unfavorable conditions by rapidly suspending their metabolism, for which they lose majority of their body water and shrink to half their normal sizes, a state known as cryptobiosis. After returning from space, they regained their former vigor within just 30 minutes of becoming hydrated.

The tiny creatures are also likely capable of producing heaps of antioxidants — such as the newfound reservoir of betalains — to combat harmful, radiation-induced changes in their bodies, scientists say.

"We have seen them do this in response to radiation on Earth," said Boothby. "We think the ways tardigrades have evolved to withstand extreme environments on this planet may also be what protects them against the stresses of spaceflight."

Originally posted on Space.com.

Tardigrades are well-known for being nearly indestructible. Now, scientists have reanalyzed ancient, amber-encased fossils, revealing when the super-tough critters may have first got the ability to enter a "tun state," which helps them survive in extreme environments.

The new findings could also explain how tardigrades survived major extinction events, including the "Great Dying," which wiped out around 90% of the planet's species around 250 million years ago.

Tardigrades, also known as water bears, are tiny eight-legged animals found in almost all habitats on Earth — from the deep sea's hottest hydrothermal vents to the freezing peaks of mountains. They can survive the harshest environments by entering a state of extreme inactivity, known as cryptobiosis, which enables them to almost completely halt their metabolism and endure dehydration, drastic temperature changes and even the vacuum of space.

In a new study, published Aug. 6 in the journal Communications Biology, researchers reanalyzed the first tardigrade fossils ever discovered — a pair of extinct water bears frozen within amber that are estimated to be around 72 million to 83 million years old.

The researchers created super high-resolution images of the fossils, which enabled them to classify the extinct species and retrace tardigrades' evolutionary history.

"Knowing when specific tardigrades originated, such as those that have the cryptobiotic ability, can help contextualize why and how these tardigrades and their ability evolved," study lead author Marc Mapalo, a researcher at Harvard University, told Live Science in an email.

Related: 8 Reasons Why We Love Tardigrades

Scientists have discovered only four tardigrade fossils. The first two, which were used in the study, were found in the 1940s on a beach near Canada's Saskatchewan River encased in a chunk of amber.

Only one of the entombed species, Beorn leggi, was ever named. "The other one was not described properly because it was too small for the author to really see anything," Mapalo said.

The researchers behind the new study used confocal fluorescence microscopy to create 3D images of the tiny fossils. This technique only illuminates specific parts of a sample, which increases the ability to see fine detail and makes the specimens look much sharper in the final photos, Mapalo explained.

After observing the shape and placement of the unidentified fossils' claws, scientists placed the tardigrade in a new genus and species, which they named Aerobius dactylus.

It turns out that not all tardigrades enter a tun state — there are two major classes of tardigrades, and in one of these classes, only one family enters cryptobiosis. By analyzing fossil features, such as the tardigrades' claws, and placing the newly-described species on an evolutionary tree, they were able to roughly estimate how long ago the split between the two major tardigrade classes occurred. That, in turn, gave them a ballpark estimate for when cryptobiosis evolved in different types of tardigrades.

"By knowing how these fossils are related to living tardigrades, we can use them to calibrate the tardigrade tree — that is to estimate when different tardigrade groups originated," Mapalo said.

The two major classes of tardigrades diverged around 500 million years ago, during the Cambrian (541 million to 485 million years ago), plus or minus around 110 million years, the study found.

These two classes of tardigrades later diverged. Cryptobiosis, they concluded, likely emerged two different times in the two types of tardigrades somewhere between 430 million and 175 million years ago. They noted that the wide time intervals encompassed mass extinctions.

The authors suggest that this death-like survival state could have helped tardigrades survive several major extinction events dating back to the Permian extinction, or Great Dying, around 252 million years ago, when massive volcanic explosions triggered uninhabitable changes in the Earth's climate. Being able to stay in a state of suspended animation for years may have helped the creatures stay alive until environmental conditions improved. However, that doesn't necessarily mean tardigrades evolved cryptobiosis in order to survive these mass extinction events.

"I think that cryptobiosis helped tardigrades to survive these events, but I would not say for sure that it's the main reason for their survival," Mapalo said.

Proteins found in tiny, indestructible tardigrades could potentially be a key ingredient in slowing the aging process in humans, scientists claim. However, it will take more work to show these proteins are a veritable fountain of youth — for now, the researchers have only early hints from lab-dish experiments..

Also known as water bears, tardigrades are near-microscopic, eight-legged creatures known for their practically superhero-like ability to withstand extreme conditions, including tolerating a severe lack of water, surviving in outer space and emerging unscathed from being fired from a gun. To survive such conditions, tardigrades transform into dehydrated balls and dial their metabolisms to near-zero.

Now, scientists have discovered that proteins found in these tiny critters can also slow metabolism in human cells in lab dishes, according to a study published March 19 in the journal Protein Science.

For the study, researchers focused on a tardigrade protein called CAHS D, which transforms into a gel-like consistency when introduced to human cells.

"Amazingly, when we introduce these proteins into human cells, they gel and slow down metabolism, just like in tardigrades," lead study author Silvia Sanchez-Martinez, a senior research scientist in the Department of Molecular Biology at the University of Wyoming, said in a statement. "Just like tardigrades, when you put human cells that have these proteins into biostasis, they become more resistant to stresses, conferring some of the tardigrades' abilities to the human cells."

Related: We finally know how tardigrades mate

Biostasis is a state of suspended animation in which organisms can tolerate unfavorable environmental changes, such as surviving for long periods without water. The scientists have now demonstrated that the proteins that make biostasis possible in tardigrades can have a similar effect on human cells.

Scientists think this new finding could eventually be harnessed to make lifesaving treatments available to people in locations where refrigeration is unavailable and to improve the storage of cell-based therapies.

"Our findings provide an avenue for pursuing technologies centered on the induction of biostasis in cells and even whole organisms [such as humans] to slow aging and enhance storage and stability," the researchers wrote in the new study. The research may even shed light on slowing down the aging process. 

Amazingly, the researchers also found that the entire process is reversible, meaning the cells' metabolism can reset back to normal after slowing.

"When the stress is relieved, the tardigrade gels dissolve, and the human cells return to their normal metabolism," senior study author Thomas Boothby, an assistant professor in the Department of Molecular Biology at the University of Wyoming, said in the statement.

Boothby and his team have been studying tardigrades extensively in their lab. Last year, they found that tardigrade proteins can be used to stabilize a drug used to treat hemophilia, a bleeding disorder.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

Space is becoming increasingly filled with human-made things. Most of these objects you would expect to find in space, such as functioning spacecraft, astronaut gear or free-floating space junk. But there are also a few peculiar items that humans have put into space — and not always on purpose. 

From dinosaur bones and a giant disco ball, to musical instruments and a gorilla suit, here are 15 of the weirdest things humans have sent to space.

A Tesla and its "astronaut" driver 

On Feb. 6, 2018, SpaceX launched company founder Elon Musk's very own cherry-red Tesla Roadster into space after the billionaire opted to use the car and its spacesuit-clad dummy passenger, known as "Starman," as the test payload on the maiden mission of the Falcon Heavy rocket.

The Starman-carrying Tesla was originally intended to be put into orbit around Mars, which sparked fears that the car could become a potential biothreat that might contaminate the planet if it ever fell to the surface. But the vehicle massively overshot the Red Planet and is now stuck in an orbit around the sun, which takes around 557 days to complete.

You can track the car and its passenger in real time on the website whereisroadster.com. As of May 2023, the Tesla had completed around 3.4 orbits around the sun and traveled more than 2.5 billion miles (4 billion kilometers). This means the car has exceeded its warranty by more than 73,000 times.

Starman has long stopped beaming images back to Earth, but astronomers predict that the passenger and car are likely to have sustained significant damage. 

Maintenance hole covers (via atomic blasts) 

Between May 28 and Oct. 7, 1957, the U.S. military carried out a series of nuclear tests in the Nevada desert in a project known as Operation Plumbbob. The tests included 29 nuclear detonations, two of which, known as Pascal-A and Pascal-B, were carried out underground, to test if nuclear fallout could be contained.

Pascal-A was carried out July 26, 1957, when an atomic bomb detonated at the bottom of a 500-foot-deep (152 meters) hole, which was covered by a 4-inch-thick (10 centimeters) iron cover. The force of the explosion "inevitably" blew the maintenance hole into the sky, Robert Brownlee, an astrophysicist at Los Alamos National Laboratory in New Mexico and lead scientist of the Pascal tests, told Business Insider before his death in 2018. Brownlee had expected that the cover would land back on Earth, but it was never recovered.

To further test what happened to the maintenance hole, Brownlee repeated the experiment on Aug. 27, 1957. This time, for Pascal-B, Brownlee recorded the experiment with a camera that shot one frame per millisecond, which revealed the cover could have reached a top speed of 125,000 mph (201,000 km/h). That speed is around five times the escape velocity of Earth, suggesting that both maintenance holes likely made it into space. It also makes the steel circles a candidate for the fastest human-made objects ever created.

Presidential hair (eventually) 

On President's Day 2023 (Feb. 20), Celestis, a Texas-based company that specializes in space burials, announced that it would be putting locks of former presidents' hair on board the upcoming "Enterprise" mission, which is scheduled to launch from Cape Canaveral, Florida. 

Genetically verified hair samples from George Washington, John F. Kennedy, Dwight D. Eisenhower and Ronald Reagan will be included on the Enterprise spacecraft, along with the remains of others, including some of the cremated remains of "Star Trek" creator Gene Roddenberry, who already had some of his ashes transported into space aboard Celestis' first flight in 1997.

The spacecraft will eventually end up beyond the outer reaches of the solar system.

A giant disco ball 

On Jan. 21, 2018, American aerospace manufacturer Rocket Lab secretly launched a massive multisided mirror into space aboard one of the company's test flights.

The unusual object, which was dubbed the "Humanity Star," was around 3 feet (1 m) wide and had 65 reflective panels on its surface. It rapidly rotated in orbit around Earth and reflected enough sunlight to Earth's surface to be visible to the naked eye. The shiny satellite was designed to be "a bright symbol and reminder to all on Earth about our fragile place in the universe."

However, the giant disco ball's time in space was short-lived. It reentered Earth's atmosphere on March 22, two months after it launched and around seven months earlier than expected, according to The Atlantic.

The Humanity Star is not the first disco ball to be launched into space. The Starshine project, which was run by the U.S. Naval Research Laboratory, launched three similar objects into space between 1999 and 2001, each of which stayed in orbit for more than a year; Japan also launched a mirror-covered satellite, called Ajisai, in August 1986, which is still in Earth orbit today, according to Live Science's sister site Space.com.

A sketched penis (possibly) 

The artist Andy Warhol drew a rather crude sketch that may or may not have ended up on the moon.

The doodle was one of six included on a tiny ceramic tile known as "Moon Museum," which was the brainchild of sculptor Forrest Myers, who petitioned NASA to place the tile on the moon. Myers' request was denied, but the sculptor supposedly contacted scientists from Bell Laboratories, who secretly attached the tile to the Apollo 12 lunar lander, which currently sits on the moon, according to The Museum of Modern Art (MoMA). However, this story has never been officially confirmed.

Warhol claimed that the sketch is actually just his initials, but we'll let you decide for yourself. 

Various Lego pieces 

Lego has a long history with space. The building kits can help youngsters (and youngsters at heart) build replicas of real-life rockets. But the famous plastic pieces have also made their way into space and have even made their home in the spacecraft they are modeled on.

In 2012, Japanese astronaut Satoshi Furukawa built a to-scale version of the International Space Station (ISS) during his stay on the station. It took him more than two hours to build the model, which is quite impressive considering the lack of gravity. 

In 2019, the Lego company also sent a model of a conceptual future lunar base to the boundary of space by attaching it to a specialized balloon.

Additionally, there are three custom Lego figurines currently circling Jupiter on board NASA's Juno probe, which was launched in 2011 to reveal insight into the gas giant and its moons. The figurines depict the Roman gods Juno and Jupiter, as well as Galileo Galilei, who discovered Jupiter's four largest moons.

Jeff Bezos (and other civilians) 

We're not trying to call Jeff Bezos a weirdo by including him on this list; the strange thing about his journey into space is that the group he traveled with was the first all-civilian crew to complete a suborbital flight.

On July 20, 2021, Bezos — along with pioneering aviator Wally Funk, physics student Oliver Daemen and Bezos' younger brother Mark — blasted off on Blue Origin's New Shepard rocket from the company's launch site in West Texas. The flight lasted only around 10 minutes, but the crew's capsule did make it past the Kármán line — the boundary between Earth's atmosphere and outer space, which lies around 62 miles (100 km) above sea level — before gently falling back to Earth.

However, there is some debate as to whether Bezos and the other civilian crewmembers can actually be considered astronauts. Some experts argue that the crew's minimal flight training and lack of expertise exclude them from earning this title, which others must work much harder to achieve. 

Dinosaur bones 

Bezos and company are not the only oddities that Blue Origin has sent into space. On May 20, 2021, the company also launched nearly 200 individual dinosaur bone fragments on another New Shepard rocket.

The bones, which date to between 66 million and 70 million years ago, likely belonged to Dromaeosaurus, a bird-like raptor that was around 7 feet (2 m) long and 2 feet (0.6 m) high at the hip, Space.com reported. The bones were auctioned off upon their return to Earth to raise money for charity.

But these fragments were not the first dinosaur bones to be sent to space. In 1985, a piece of a vertebra and an eggshell from a baby Maiasaura were flown on NASA's space shuttle Challenger. And in 1998, a 210-million-year-old Coelophysis skull flew on Challenger's successor, space shuttle Endeavour. Parts of a Tyrannosaurus rex were also launched on the first test flight of NASA's Orion spacecraft in 2014, according to Space.com.

Tardigrades 

Lots of different animals have been sent into space. Some of these you probably already know about, such as dogs, apes, monkeys and rodents. But lots of other creatures have made it into space, including cats, frogs, fruit flies, tortoises, fish and jellyfish.

However, the weirdest animals to be sent to space are arguably tardigrades, also known as water bears, which are renowned for being able to survive extreme conditions. In 2007, they also became the first animals to survive direct exposure to space when they were strapped to the outside of the Russian Foton-M3 spacecraft as it orbited Earth for 12 days, according to the European Space Agency. 

A follow-up paper, published 2008 in the journal Current Biology, revealed that 68% of the tardigrades managed to survive direct exposure to space, despite the extreme cold, dehydration and bombardment by cosmic radiation.

A gorilla suit 

Astronauts also seem to enjoy dressing up as animals in space.

In 2016, retired astronaut and current U.S. Sen. Mark Kelly smuggled a full-body gorilla suit to his identical twin Scott while he was staying on board the ISS. This resulted in a viral video, in which Scott surprised and chased British astronaut Tim Peake through the ISS modules (although Peake later admitted to being in on the joke).

Mark Kelly had originally tried to smuggle a gorilla suit to Scott in 2015, but the SpaceX Falcon 9 rocket it was stashed on exploded in a ball of flames shortly after liftoff.

Luke Skywalker's lightsaber 

The original Star Wars trilogy, released between 1977 and 1983, is widely credited for inspiring an entire generation of astronauts and space scientists. So it is fitting that one of the movies' most famous props — Luke Skywalker's lightsaber — would eventually end up in space.

The lightsaber was launched into space in 2007 with a team of astronauts who delivered and assembled the Harmony module (aka Node 2) to the ISS. The launch coincided with the 30th anniversary of the first Star Wars film, "A New Hope," but the lightsaber is actually Luke's second laser sword (the green one), which featured in the third film, "Return of the Jedi."

Luke's lightsaber isn't the only Star Wars memorabilia to have been sent into space. In 2017, as part of the marketing for "The Last Jedi" — the second film in the newest trilogy — Disney arranged for a replica of the spherical orange droid BB-8 to be sent to the ISS for the astronauts to play with, Space.com reported.

Pizza delivery 

In 2001, Pizza Hut became the first company to deliver food to space when it sent a pizza to the ISS on board a resupply rocket. The recipient of the pizza was Yuri Usachov, who was filmed eating the tasty treat along with other Russian cosmonauts.

The record-breaking delivery was a shameless marketing ploy, which cost the company more than $1 million ($1.7 million in today's dollars). But the chefs who cooked the pizza still had to make some special considerations for its unusual journey: Extra seasoning was added to the food because astronauts can lose their sense of taste in space, and salami was used instead of pepperoni because it had a longer shelf life and the pizza had to be prepared well in advance of the launch, the BBC reported at the time.

Interestingly, NASA astronauts aboard the ISS at the time were forbidden from eating the pizza because of the agency's strict rules on corporate sponsorships.

The pizza isn't the only food that has been successfully delivered to the ISS. In December 2021, Uber Eats announced that it had delivered food to the ISS via Japanese entrepreneur and space tourist Yusaku Maezawa, who briefly visited the station, according to CNET. The meal included miso-coated mackerel and chicken with bamboo shoots.

Amelia Earhart's watch 

Amelia Earhart was a trailblazing aviator who in 1932 famously became the first woman to cross the Atlantic Ocean solo, as well as achieved other significant firsts and broke multiple aviation records. The pioneering pilot was presumed dead in 1937, when her plane was lost as she attempted to circumnavigate the globe. Her plane and body were never found.

Earhart's story has been an inspiration for many young female aviators and astronauts, including NASA astronaut Shannon Walker, who took Earhart's personal wristwatch — which Earhart wore on her famous trans-Atlantic flight — with her to the ISS in 2010, according to Experts Watches. (Earhart wore a different watch on her fatal final journey.)

Parts of the Wright brothers' plane 

Continuing with the aviation trend, parts of Orville and Wilbur Wright's first plane, the Wright Flyer, have also made it into space — on two separate occasions. 

The biplane, which is also known as the Kitty Hawk, is famous for being the first airplane to make a sustained flight with humans aboard, after making four brief flights on Dec. 17, 1903, before being blown over and destroyed. Its longest flight lasted only 59 seconds, during which the plane traveled 852 feet (260 m).

In 1969, Neil Armstrong — the first person to walk on the moon — took parts of the Wright Flyer with him to the moon during NASA's Apollo 11 mission, Time magazine reported. The fragments, which included four pieces of muslin fabric from the plane's wing and two pieces of its propeller, were included in Armstrong's personal preference kit, a small bag of personal belongings that each astronaut could bring onto the lunar module.

And in 2021, another swatch of fabric from the airplane landed on Mars along with NASA's Perseverance rover and Ingenuity helicopter. The plane part is safely secured beneath the solar panels on Ingenuity, which has since made more than 50 flights on the Red Planet.

Musical instruments 

For astronauts living on the ISS, there can be a psychological cost to spending so much time away from Earthly comforts. To overcome these obstacles, several astronauts have taken instruments — including keyboards, guitars, flutes, bells, bagpipes, a saxophone and even a didgeridoo — with them to space. 

For the most part, playing an instrument in space is very similar to playing it on Earth, but microgravity can pose issues. For example, if astronauts play a wind instrument, like the flute, on the ISS, they must keep their feet in loops to stop them from being propelled backward by the air they are blowing out of the instrument, according to NASA.

However, there is also a safety concern with taking instruments, such as guitars, on board the ISS because they are flammable and therefore must be safely stored when not in use. It is also expensive to put instruments into space; it costs around $10,000 per pound ($4,500 per kilogram) of cargo launched.

Honorable mention — Zero-G indicators

Among astronauts, it has become a tradition for crews to select an unusual item as their "zero-G indicator," an object that begins to float around them when gravity lessens. Examples of zero-G indicators include an Einstein doll, Snoopy the dog, Baby Yoda (or Grogu), toy dinosaurs, a planet Earth plushy, a stuffed penguin and a Buzz Lightyear figure, to name a few. 

Tardigrades — those darling, near-microscopic critters that are nearly indestructible — carry proteins that could keep critical drugs and medical treatments stable without refrigeration, scientists say.

In a study published Monday (March 20) in the journal Scientific Reports, scientists tested this idea with human blood clotting factor VIII, a protein used to treat an inherited bleeding disorder called hemophilia A. Due to a genetic mutation, people with this disorder don't make enough factor VIII and their blood can't clot properly. People with hemophilia A bleed spontaneously, and bleed excessively after injury or surgery. 

Treating hemophilia A usually involves injecting factor VIII into the body, to make up for the patient's deficiency. Many factor VIII products require refrigeration, and those that don't can typically be kept at room temperature for only a limited amount of time and within a narrow temperature range. 

Tardigrades, on the other hand, have a remarkable ability called anhydrobiosis, where they essentially dry themselves out and enter a state of suspended animation. In this state, the so-called water bears can withstand temperatures as low as minus 328 degrees Fahrenheit (minus 200 degrees Celsius) and as high as 300 F (148.9 C).

Related: Tardigrades survive being dried out thanks to proteins found in no other animals on Earth

The study authors wanted to see if the tardigrade's remarkable resilience could be carried over to medical treatments.

"Our work provides a proof of principle that we can stabilize Factor VIII, and likely many other pharmaceuticals, in a stable, dry state at room or even elevated temperatures using proteins from tardigrades," senior study author Thomas Boothby, an assistant professor of molecular biology at the University of Wyoming, said in a statement. "And, thus, provide critical live-saving medicine to everyone everywhere."

The team drew two substances from the tardigrade Hypsibius exemplaris: a sugar called trehalose and a protein called cytoplasmic abundant heat soluble (CAHS) D. Both substances help preserve the  tardigrades' bodies during anhydrobiosis so that they survive to be "rehydrated" later on.

The team tweaked both substances' biophysical properties to boost their ability to stabilize factor VIII. They then used the substances to store factor VIII without refrigeration and under unfavorable conditions, such as repeated dehydration and rehydration, extreme heat and long-term dry storage. Both compounds worked, but CAHS D worked better than trehalose, the team noted.

The authors think this approach could potentially be used for other medicines that currently require refrigeration. But we're still in the early days of this research.

"This will not only be beneficial for global health initiatives in remote or developing parts of the world, but also for fostering a safe and productive space economy which will be reliant on new technologies that break our dependance on the cold-chain for the storage of medicine, food, and other biomolecules," the authors wrote.

Tiny tardigrades can survive conditions that would kill most other forms of life. By expelling their body's water and transforming into a seemingly lifeless ball called a tun, they enter a state of dried-up suspended animation in which they can survive for decades without food and water and withstand extreme temperatures, pressures and even the vacuum of space. However, little is known about what drives this protective mechanism and what keeps tardigrades from succumbing to the stresses of prolonged desiccation. 

Now, a new study reveals how tardigrades survive without any water at all: Unique proteins turn the insides of tardigrade cells into gel, thereby preventing the critters' cell membranes from crinkling and collapsing. This strategy is completely different from those seen in other types of animals that can survive dry periods.

In fact, "no such proteins have been reported in other desiccation-tolerant organisms," said Takekazu Kunieda, a biologist at the University of Tokyo who led the new research, published Sept. 6 in the journal PLOS Biology.

Surviving desiccation 

Tardigrades, also known as water bears or moss piglets, are a group of microscopic animals with plump bodies and eight legs ending in disproportionately delicate claws. They're famously resilient, able to survive exposure to space, freezing temperatures, and boiling for an hour (though they can be killed by longer exposure to hot water).  

Scientists have long been interested in how tardigrades do this. Many animals that can survive long periods of desiccation, such as aquatic crustaceans known as brine shrimp, use sugars called trehalose to essentially freeze their cells in a glass-like state that protects their inner workings until the animals are exposed to water again. 

But tardigrades don't have much trehalose. What they do have are numerous proteins not found in other animals. These proteins are hard to understand, because in a non-tun tardigrade, they appear disorganized and disordered, though a 2017 genetic study found that some of these disordered proteins seem to promote a glassy state in dried-out tardigrades, much like trehalose does in other animals. 

Related: Frozen tardigrade becomes first 'quantum entangled' animal in history, researchers claim

The new research focused on a group of tardigrade-specific proteins known as cytoplasmic-abundant heat-soluble (CAHS) proteins. In tardigrades, these proteins float around the cytoplasm, or liquid filling the cells. Kunieda and his colleagues discovered these proteins a decade ago, and other research groups found that the proteins were involved in the survival of tardigrades during desiccation. But no one knew how. 

Cooperative proteins 

Kunieda and his team ended up circling back to CAHS proteins while looking for tardigrade proteins that changed form upon stress. They identified more than 300, and CAHS proteins were among them. 

To learn what CAHS proteins do to protect tardigrades under duress, the researchers dehydrated CAHS-carrying cells and analyzed how the proteins changed. They found that when the cells were threatened with desiccation, these proteins condensed, forming a network of filaments. These filaments shored up the cell, transforming the cytoplasm into a gel-like state and preventing the cell from collapsing as water leached out. This condensation happened in minutes and reversed just as quickly. Within six minutes of rehydration, a cell could be up and running normally again. 

In their experiments, the researchers found that CAHS could make insect cells more resilient to desiccation, but those CAHS-enhanced cells still weren't as tough as tardigrade cells. That means CAHS wasn't working alone, Kunieda told Live Science. 

"It seems obvious for me that other factors are needed to reproduce the tolerant ability of tardigrades," he said.

Fortunately, there are plenty of tardigrade proteins to study; the researchers identified more than 300 that react to stress. Future findings could have applications beyond tardigrades — for example, to help scientists develop better preservatives for improving the shelf life of vaccines and medication, Kunieda said. 

Originally published on Live Science

The next time you're fidgeting in an uncomfortable seat on a crowded train or airplane and wishing for a better way to travel, be grateful that you aren't a tardigrade. For these near-microscopic animals, getting from one place to another sometimes means being swallowed by a snail, riding in its guts and then exiting the mollusk via the anus, on a clump of feces.

Despite the obvious drawbacks of this arrangement, traveling by snail is certainly faster for a wee tardigrade than walking. Unfortunately, tardigrades have only about a 30% chance of surviving the trip, as they run the risk of being digested along the way, scientists discovered.

Tardigrades, also known as moss piglets or water bears, measure between 0.002 and 0.05 inches (0.05 to 1.2 millimeters) long, and are surprisingly cute for such small organisms, with endearingly tubby bodies, round faces and eight stubby legs. They are found almost everywhere on Earth where there's liquid water, but little is known about how such small creatures reach and populate new environments. Winds and water are thought to be the primary conveyors of microbial life (including tardigrades) from one ecosystem to another, and some research has suggested that larger animals may also play a role, serving as buses and taxis for microscopic stowaways. 

But there was little direct evidence of tardigrade dispersal by way of snail ingestion and defecation — until now, scientists recently reported.

Related: 8 reasons why we love tardigrades 

About two years ago, lead study author Tommi Vuori, a master's student in the Department of Biological and Environmental Science at the University of Jyväskylä in Finland, first considered the notion of animals swallowing and then dispersing tardigrades, he told Live Science in an email. A conversation with his supervisor about living tardigrades found in bird feces, described by researchers in 2020 in the journal Polar Biology, led Vuori to another study published in the Journal of Parasitology in 1962, in which scientists described finding live tardigrades in land snail feces. 

These examples inspired him to seek other instances of tardigrade dispersal by land animals, Vuori said. He decided to look for animals that ate moss, where tardigrades are often found, and with feces that "would be easy to sample."

"That's the point when copse snails (Arianta arbustorum) came to my mind," Vuori said. "Everyone who has done any gardening in Finland knows that those snails eat almost anything." So Vuori and his colleagues sampled feces from 21 copse snails collected from a community garden, brought them into the lab and spent around 30 hours examining them, finding tardigrades from two genuses — Macrobiotus and Hypsibius — in about 25% of the feces, according to the study.

"A total of 10 tardigrades were recovered from wild snail feces of which 5 were alive," the authors reported March 31 in the journal Ecology. Some of the tardigrade survivors even reproduced after their recovery, providing the first evidence of tardigrade reproduction after emerging from an animal's gut.

The researchers then fed other tardigrades to copse snails, finding that 218 of the 694 tardigrades (about 30%) survived the ordeal and were pooped out while still alive; 78 were dead on arrival, and the rest "are supposed to have been digested," the authors wrote.

Tardigrades protect themselves from potentially lethal conditions — such as temperature extremes, ultraviolet radiation, the vacuum of space, quantum entanglement and even being shot out of a high-speed gun — by entering what is known as a tun state, in which they expel moisture from their bodies and slow metabolic processes. But becoming a tun is impossible during a snail journey because the gut interior is exceptionally moist, so a traveling tardigrade would lack the protection that a tun state might offer, the scientists reported. 

Most of the snails carried their water bear passengers for two days before ejecting them by process of elimination. Copse snails can travel a maximum distance of about 13 to 16 feet (4 to 5 meters) per day; that means a tardigrade traveling by a snail could relocate — and reproduce — dozens of feet from where it started, which could help wee water bears establish populations in new territories, the researchers wrote.

"Tardigrades have been previously found alive from the feces of snails and birds, but their reproductive ability after passage through the digestive system has been ignored," Vuori said in the email. Finding that tardigrades can reproduce after passing through the gastrointestinal tract of an animal — in this case, a land snail — is therefore an important discovery, and it hints at the water bears' future success in their new home, according to the study.

"Merely transporting an individual to another location is not sufficient, but reproductive ability is prerequisite for colonizing novel habitats," Vuori said.

Originally published on Live Science.

Traveling by snail may not sound like the quickest way to get around, but it's faster than walking ... if you're a tardigrade. 

Eight-legged, endearingly tubby tardigrades — near-microscopic organisms that are also known as water bears or moss piglets — can hitch rides on land snails to journey farther than they could under their own power, new research finds. But while snail-surfing helped tardigrades disperse into new locations, a coating of the snails' slimy mucus often proved fatal to tardigrade riders.

Tardigrades measure from 0.002 to 0.05 inches (0.05 to 1.2 millimeters) long and can live nearly anyplace on Earth where there's liquid water: in oceans, in rivers and lakes, and in soggy clumps of lichen and mosses that grow on rocks and trees. Wee water bears can also endure circumstances that would be fatal to most forms of life, such as extreme temperatures, crushing pressure, ultraviolet (UV) radiation, the vacuum of space and even being shot out of a high-speed gun, by exercising a superpower known as anhydrobiosis — expelling nearly all the water in their bodies. 

In this desiccated and scrunched-up form, called a tun state, tardigrades can survive punishing conditions and can persist for years; some tardigrade tuns that were frozen for 30 years were successfully resuscitated in 2016 and immediately began reproducing, Live Science previously reported. And researchers recently found that active and tun-state tardigrades alike could be picked up and carried by land snails that share their habitats.

Related: 8 reasons why we love tardigrades 

Though tardigrades can swim and walk, their tiny legs don't carry them very far. A tardigrade in search of a new neighborhood therefore needs outside assistance, such as wind, flowing water or an obliging host animal that's damp enough to keep the traveler alive. Little is known about how tardigrades interact with snails in their natural habitats, but because water bears often live side by side with land snails (which are famously moist), the researchers suspected that snails could potentially be "perfect vehicles for tardigrades" to travel from place to place, according to a study published April 14 in the journal Scientific Reports.

"Checking available literature, we found out that this topic was almost unexplored," said lead study author Zofia Książkiewicz-Parulska, an assistant professor in the Institute of Environmental Biology at Adam Mickiewicz University (UAM)  in Poland, and co-author Milena Roszkowska, a UAM doctoral candidate in the Department of Bioenergetics. The only prior research on the subject — dating to more than 55 years ago — described observations of tardigrades that traveled by riding inside snails' guts after being eaten, then exiting in the mollusks' feces, the researchers told Live Science in an email.

To test their hitchhiking tardigrade hypothesis, the study authors collected grove snails (Cepaea nemoralis) and Milnesium inceptum tardigrades; the two species coexist in terrestrial ecosystems across Western Europe, and both are at their most active under humid conditions. Grove snails' shells measure up to 0.9 inches (22 mm) in diameter, making the mollusks good candidates for carrying tardigrades, the researchers reported. 

In their experiments, the scientists sent snails crawling through drops of water and over pieces of moss containing tardigrades, to see how many "piglets" the snails would pick up. Active and tun-state tardigrades readily adhered to the snails' slime-covered bodies for short rides; the snails transported 38 tardigrade hitchhikers from water droplets, and they gathered 12 tardigrade riders from moss. In some of the experiments, the researchers surrounded the tardigrades' watery pool with a physical barrier; in those settings, the only tardigrades that crossed that border did so with help from a snail "vehicle," according to the study. 

But there was also a deadly downside to the snails' sticky mucus coating, once it dried on the tardigrades' tiny bodies.

Only a fraction of tuns that were coated in dried snail mucus — about 34% — could be revived after 24 hours. By comparison, 98% of control group tuns that hadn't been slimed became fully active again once they were rehydrated. Snail mucus is mostly water but it dries quickly, and mucus-coated tuns that were briefly revived by the water in snail slime may not have been able to re-enter a tun state swiftly enough as the slimy envelope around them hardened, and they froze in "very weird poses" that were not fully-formed tuns, the scientists said in the email. 

Other forces can transport tardigrades much farther than snails can; prior studies have shown that wind gusts on glaciers can carry tardigrades over distances greater than 620 miles (1,000 kilometers), the study authors wrote. However, a tardigrade that rides the wind may end up someplace that isn't very hospitable to water bears. A journey by snail is more likely to deposit its rider in an environment that's similar to the one where it started — one where tardigrades (and snails) are likely to thrive. 

Further experiments could confirm if tardigrade eggs can hitchhike on snails too, and could test how far a tardigrade might travel by snail, the researchers said. But even if the traveling tardigrade's new home is just a few centimeters away, that's still far enough to improve genetic diversity among different populations of water bears, according to the study.

That is, as long as the tardigrade hitchhiker avoids being smothered by snail slime before its trip is over.

Originally published on Live Science.

Tardigrades — those microscopic, plump-bodied critters lovingly known as "moss piglets" — have been put through the ringer for science. The amazingly durable creatures have been shot out of guns, bathed in boiling-hot water, exposed to intense ultraviolet radiation and even (accidentally) crash-landed on the moon, all to test the limits of their impressive "tun" state — a survival mechanism wherein tardigrades curl up into shrunken, dehydrated balls and suspend their biological functions indefinitely in order to endure extreme environmental conditions.

Now, researchers have exposed tardigrades to the coldest temperatures and highest pressures that moss piglets have ever survived — not just to test the critters' biological limits, but also to see whether a frozen tardigrade could be incorporated into two quantum entangled electric circuits, then later revived to its normal active state.

The results, reported in a new paper published to the preprint database arXiv, suggest that, yes — scientists may be able to add "temporary quantum entanglement" to the tardigrade's growing list of accomplishments. However, early responses to the paper have taken issue with this finding.

If the findings ultimately withstand peer review, then this experiment will represent the first time a living animal has been quantum entangled — a bizarre phenomenon typically confined to the smallest subatomic particles.

Spooky action in a piglet

The phenomenon of quantum entanglement is so strange that even Albert Einstein had his doubts about it, famously nicknaming the process "spooky action at a distance." Essentially, the effect occurs when two teeny, tiny subatomic particles become bound to one another so that a change to one particle's spin or momentum instantaneously changes the other particle in the same way — even when the two particles are separated by incredibly large distances.

This effect may be able to transcend the subatomic realm, as scientists attempted to prove in a 2018 paper in the Journal of Physics Communications. That team found that certain photosynthetic bacteria were capable of becoming entangled with light photons, when the resonant frequency of light in a mirrored room eventually synchronized with the frequency of electrons in the bacteria's photosynthetic molecules, Live Science previously reported.

The authors of the new arXiv paper decided to test whether a multicellular organism like a tardigrade could develop such a relationship. In their experiment, the team collected three tardigrades from a roof gutter in Denmark. In their animated state, the tardigrades measured between 0.008 and 0.018 inches (0.2 to 0.45 millimeters) — however, after the researchers froze the tardigrades and sent them into a tun state, the animals shrunk to about a third of that size.

From there, the team froze the tardigrades even further, cooling them to a fraction of a degree above absolute zero — the coldest temperature a tardigrade has ever been exposed to and survived.

The team placed each frozen tardigrade between two capacitor plates of a superconductor circuit that formed a quantum bit, or "qubit" — a unit of information used in quantum computing. When the tardigrade came into contact with the qubit (named Qubit B), it shifted the qubit's resonant frequency. That tardigrade-qubit-hybrid was then coupled to a second nearby circuit (Qubit A), so that the two qubits became entangled. Over several tests that followed, the researchers saw that the frequency of both qubits and the tardigrade changed in tandem, resembling a three-part entangled system.

Seventeen days after the tardigrades entered their tun states, the researchers gently warmed them up in an attempt to revive them. One of the tardigrades returned to its animated state, while the other two died. That survivor effectively has become the first quantum entangled animal in history, the researchers claimed.

"While one might expect similar physical results from inanimate objects with similar composition to the tardigrade, we emphasize that entanglement is observed with [an] entire organism that retains its biological functionality post experiment," the team concluded in their paper. "At the same time, the tardigrade survived the most extreme and prolonged conditions it has ever been exposed to."

While the paper has not yet been peer-reviewed, early responses from the scientific community have been critical. Douglas Natelson, Department Chair of physics and astronomy at Rice University in Texas, wrote on his blog that the experiment "did not entangle a tardigrade with a qubit in any meaningful sense."

"What the authors did here was put a tardigrade on top of the capacitive parts of one of two coupled qubits," Natelson wrote. "The tardigrade is mostly (frozen) water, and here it acts like a dielectric, shifting the resonance frequency of the one qubit that it sat on… This is not entanglement in any meaningful sense."

Ben Brubaker, a science writer and former physicist agreed.

"The qubit is an electrical circuit and putting the tardigrade next to it affects it through the laws of electromagnetism we've known about for more than 150 years," Brubaker tweeted. "Putting a speck of dust next to the qubit would have a similar effect."

Whether or not the tardigrade experienced any "spooky action" from the qubits it was attached to, the study does show that moss piglets are even more durable than previously thought. As exciting as a "quantum tardigrade" sounds, this experiment should at least serve as a reminder that regular-old tardigrades are fascinating enough on their own.

Originally published on Live Science.

The growing demand for space exploration is increasing the chances of alien organisms invading Earth and of Earth-based organisms invading other planets, scientists have argued in a new paper.

The researchers point to humanity's record of moving species to new environments on Earth, where those organisms can become invasive and harm the native species; they say such behavior suggests the same could happen with alien life from another planet contaminating Earth and vice versa, according to the paper, published Nov. 17 in the journal BioScience.

"The search of life beyond our world is an exciting endeavour that could yield an enormous discovery in the not-too-distant future," lead author Anthony Ricciardi, a professor of invasion biology at McGill University in Montreal, told Live Science in an email. "However, in the face of increasing space missions (including those intended to return samples to Earth), it is crucial to reduce the risks of biological contamination in both directions."

Ricciardi and his colleagues use the paper to call for more collaborative studies between astrobiologists searching for extraterrestrial life and invasion biologists studying invasive species on Earth. "We can only speculate on what kinds of organisms might be encountered if astrobiologists were to find life," Ricciardi said. "The most plausible life-forms would be microbial and probably resemble bacteria." 

Related: 9 strange, scientific excuses for why humans haven't found aliens yet

The scientists consider the risk of interplanetary contamination to be extremely low, partly because the harsh conditions of outer space make it difficult for potential hitchhiking organisms to survive a ride on the outside of a human spacecraft. However, we should still be cautious of interplanetary contamination based on the negative impacts that invasive species have had on Earth, according to Ricciardi.

Humans have damaged ecosystems around the world by allowing organisms to invade new environments they'd never reach naturally. For example, a fungus from South America called Austropuccinia psidii was introduced to Australia in unknown circumstances and is taking over the country's native eucalyptus trees, stunting their growth and sometimes killing them. 

The researchers noted that insular ecosystems that evolve in geographical isolation, such as on islands and in countries like Australia, are particularly vulnerable to invasive species, because the native wildlife in those places hasn't evolved adaptations to deal with such invaders. "Biological invasions have often been devastating for the plants and animals in these systems," Ricciardi said. "We argue that planets and moons potentially containing life should be treated as if they were insular systems." 

For evidence of interplanetary contamination, the researchers cited the Israeli Beresheet spacecraft that crashed into the moon in 2019 while carrying thousands of tardigrades, microscopic animals that can survive extreme conditions, including the vacuum of space, Live Science previously reported. A 2021 study published in the journal Astrobiology concluded that the creatures probably wouldn't have survived the impact of the lunar crash but that the incident demonstrates the potential for biological spills. 

Space agencies such as NASA have long been aware of the potential risks of biological contamination, and planetary protection policies have been in place since the 1960s, according to Ricciardi. "However, unprecedented risks are posed by a new era of space exploration aimed at targeting areas most likely to contain life," Ricciardi said. This includes the rise in private space exploration companies such as SpaceX that are making space more accessible, according to the paper. SpaceX, for example, aims to travel to Mars and beyond with its SpaceX Starship program. 

The researchers suggest increasing biosecurity protocols associated with space travel, focusing on the early detection of potential biological contaminants and developing plans for a rapid response to any such detections. 

Planets and moons have always exchanged material via meteorites, but human space exploration could accelerate contamination, said Jennifer Wadsworth, an astrobiologist at Lucerne University of Applied Sciences and Arts in Switzerland who was not involved in the paper.

The new paper is an "excellent overview" of the current and continuous need for strict and up-to-date planetary protection rules, Wadsworth said. One major issue is that current planetary protection guidelines are not mandatory, Wadsworth told Live Science. 

"The line between exploration and conservation is a thin one," Wadsworth said. "One shouldn't be abandoned at the cost of the other, but both require careful consideration and, most importantly, compliance." 

Originally published on Live Science.

Tardigrades, often called water bears or moss piglets, are tiny aquatic animals. Under a microscope, you can see their plump, segmented bodies and flat heads. They have eight legs, each tipped with four to eight claws, and look a bit like the caterpillar from "Alice in Wonderland." Though tardigrades are cute, they are also nearly indestructible.

Tardigrades were discovered in 1773 by the German zoologist Johann August Ephraim Goeze, who nicknamed them "little water bears." Three years later, Italian biologist Lazzaro Spallanzani named the group "Tardigrada," or "slow stepper," for the way they move.

Scientists have identified about 1,300 tardigrade species. They can survive punishing heat, freezing cold, ultraviolet radiation and even outer space. They do this by becoming dried-out little balls, called "tuns," and almost stopping their metabolism (the way they get energy from food), reviving only when conditions are better. In fact, these tough little water bears will probably survive long after humanity is gone, research has found.

5 fast facts about tardigrades

• Where they live: Water bears, true to their name, live in water, from oceans to drops of water on plants. They can live high in the mountains and deep in the ocean.
• What they eat: Tardigrades mostly eat plants and algae. Some species eat other, smaller creatures, like microscopic worms and tiny, wheel-shaped animals called rotifers.
• What makes them special: They curl up into dried-up balls that can survive boiling water, freezing cold and outer space. This is called a tun state.
• How big they get: They grow to about the size of the period at the end of this sentence.
• How long they live: Water bears may survive up to a century in their tun state. Outside their tun state, they live between 3 months and 2.5 years.

Everything you need to know about tardigrades

Tardigrade taxonomy

Here is the taxonomy, or classification, for the tardigrade, according to the Integrated Taxonomic Information System (ITIS):

Kingdom: Animalia

Subkingdom: Bilateria

Infrakingdom: Protostomia

Superphylum: Ecdysozoa

Phylum: Tardigrada

Tardigrade pictures

Discover more about tardigrades

—1st tardigrade fossils ever discovered hint at how they survived Earth's biggest mass extinction

—Tardigrades survive being dried out thanks to proteins found in no other animals on Earth

—We finally know how tardigrades mate

Scientists discovered an incredibly rare fossil suspended in 16 million-year-old amber: a never-before-seen species of tardigrade, a pudgy, aquatic critter that rarely crops up in the fossil record. 

Modern-day tardigrades, also known as water bears or moss piglets, can be found in just about any environment with liquid water, from the depths of the ocean to the thin water films that coat terrestrial mosses. The tiny creatures are famous for their survival skills; by expelling most water from their bodies and drastically slowing their metabolism, tardigrades enter a state akin to suspended animation in which they can withstand extreme temperatures, pressure and radiation.

But although tardigrades are nearly impossible to destroy when alive, their small size and lack of hard tissue mean that very few tardigrade fossils have ever been discovered — only three, to be exact. The species of two of these fossils, found in Canada and New Jersey, have been formally named; the other, found in West Siberia, remains unnamed. 

Related: 8 reasons why we love tardigrades 

But now, in a new study published Tuesday (Oct. 5) in the journal Proceedings of the Royal Society B: Biological Sciences, scientists have introduced a newfound species of tardigrade that they discovered in amber from the Dominican Republic. The fossil dates to the Miocene epoch  (23 million to 5.3 million years ago) and is so well preserved that the team was able to place the newfound water bear, named Paradoryphoribius chronocaribbeus, within the tardigrade "tree of life."

"There's really only two clear tardigrades from the fossil record," referencing the two fossils whose species are known, "so this is really exciting to find a third," said Frank Smith, an evolutionary developmental biologist and assistant professor at the University of North Florida who was not involved in the new study. And thanks to the quality of the fossil, the researchers were able to apply the same techniques used to identify living tardigrades, which helped the team determine how the newfound species relates to modern-day water bears, Smith said.

The tardigrade measures less than 0.02 inches (0.6 millimeters) long, so how did the researchers spot it? It was really a matter of luck, first author Marc Mapalo, a doctoral student in the Department of Organismic and Evolutionary Biology at Harvard University, told Live Science.

Mapalo's collaborators at the New Jersey Institute of Technology initially acquired the amber to look for ants captured in the material; the team, led by evolutionary biologist Phillip Barden, studies the evolution of social insects such as ants and termites. 

"They'd had the amber for months, but they'd only been looking at ants," Mapalo said. But at some point, a sharp-eyed lab member noticed a stumpy, caterpillar-like shape with teeny, clawed legs jutting out of its underside. Lo and behold, they'd found a tardigrade floating in the amber, alongside three ants, a beetle and a flower. 

"It was more luck that they saw it … because it's not something they look for," Mapalo said. Upon learning about the fossil, Mapalo said he was "really surprised," since the chances of finding a tardigrade fossil are so slim. As someone who loves water bears so much that he once wrote a song about them, he was eager to examine one of the few known tardigrade fossils.   

In addition to finding the fossil, the team lucked out in that the tardigrade sat fairly close to the surface of the amber, meaning that light from their microscopes could easily reach the sample. Using techniques called transmitted light and confocal fluorescence microscopy, the researchers examined both the external anatomy, such as the tardigrade's claws, and some internal morphology, including various hard structures found in the critter's foregut — roughly akin to its "throat."

Related: Ancient footprints to tiny 'vampires': 8 rare and unusual fossils

"This is the first tardigrade fossil where we were able to visualize the internal morphology," Mapalo said. 

Based on the shape and placement of the tardigrade's claws, the researchers identified the water bear as part of the Isohypsibioidea superfamily, a diverse group of modern-day tardigrades. This makes P. chronocaribbeus the oldest known member of the superfamily. 

However, aspects of the water bear's internal anatomy set it apart from related tardigrades. In particular, a hard structure located between the mouth and esophagus, called a macroplacoid, bore a unique shape; whereas other Isohypsibioidea members have two to three thick macroplacoids, the new tardigrade fossil had only a single thin one, marked with a ridge.

"Because of this, it does not correspond to any extant genus within this superfamily," Mapalo said. And for this reason, the team created a brand-new genus and species to accommodate P. chronocaribbeus.

In its heyday, P. chronocaribbeus probably lived in similar conditions to modern-day water bears, hanging out on moss cushions and slurping liquid from plant cells, Smith said. "If we went back 16 million years to this locale, we'd probably find this species all over the place." And in theory, more tardigrade fossils might be lurking in Dominican amber from the same region, as well as in other amber deposits around the world, he said.

As of now, very few people are on the lookout for tardigrade fossils in amber, so if more scientists joined the hunt, more tardigrade fossils might be found, Mapalo said. 

To the naked eye, "I don't even know if it'd look like a speck of dust; you probably wouldn't see it at all," Smith said. So to spot the pudgy sea critters, scientists would need to carefully inspect all their amber samples under a microscope. But generally speaking, "if you find amber, more than likely, there were tardigrades living somewhere near the tree that was producing that amber … So it's worth looking in any amber sample for tardigrades," he said. 

Until more tardigrade fossils are found, Mapalo plans to study the genetic and molecular mechanisms that drive growth and development in living tardigrades. Currently, he's visiting Smith's lab in Florida to study how tardigrade claws develop; this line of research could help reveal what forces drove tardigrade evolution, causing tardigrades to adopt the familiar, plump body plan we now know and love.

In addition, Mapalo wants to study the first fossil tardigrade ever found, which happens to be housed at Harvard. The fossil, identified as the species Beorn leggi, was found in 1964 near Cedar Lake in Manitoba and is about 78 million years old, meaning it dates to the Upper Cretaceous, the authors noted in their report. Because high-resolution imaging techniques were not available at the time, however, the water bear's exact relationship to modern-day species has yet to be determined. 

Originally published on Live Science.

Pudgy, ungainly tardigrades are among the smallest legged animals on Earth, and these microscopic water bears lumber around like chubby-thighed toddlers. But most creatures as small as tardigrades don't even have legs, so scientists recently analyzed tardigrades in motion to better understand how they use their limbs. 

Tardigrades, also known as moss piglets, have segmented bodies and four pairs of legs. They scoot through deep sea sediments and sandy river bottoms, and scurry over lichens and moss on land, scampering toward prospective mates and food or away from predators. 

Footage of scuttling tardigrades in the species Hypsibius exemplaris revealed that their movements closely resembled locomotion in insects about 500,000 times their size, despite being separated by around 20 million years of evolution and belonging to a different phylum. The step patterns of insects and other arthropods (invertebrates with segmented bodies and jointed legs) change when the animals speed up, and tardigrades' steps follow similar patterns when they walk faster, the new study found.

Related: 8 reasons why we love tardigrades

Tardigrades, of which there are about 1,300 known species, are notorious for being hard to kill; they can survive exposure to extreme temperatures, solar radiation and the vacuum of space. But few studies have examined these hardy creatures in more ordinary circumstances, and prior to the new study, scientists knew next to nothing about how tardigrades walk, said lead author Jasmine Nirody, a researcher and independent fellow at the The Rockefeller University Center for Studies in Physics and Biology in New York City.

Most microscopic, soft-bodied animals don't have legs, so it's also difficult to observe exactly how such tiny animals move. By analyzing walking tardigrades, literally one step at a time, the researchers also hoped to uncover clues about locomotion in general on a very, very small scale, Nirody told Live Science. 

"We saw tardigrades as giving us this porthole into both of these things that we don't know that much about," Nirody said.

Nirody's team looked at adults in the species H. exemplaris, which measure up to 0.02 inches (0.5 millimeters) long. All eight of their legs are structurally similar, but the pair closest to their rear ends has fewer muscles than the others. While this pair of legs plays some part in locomotion, most of the hard work is divided among the other six limbs, the scientists reported Aug. 31 in the journal Proceedings of the National Academy of Sciences (PNAS).

At first, the researchers tested tardigrades on slick glass slides, but they found that the water bears had a hard time propelling themselves over the slippery surface. Walking was easier for the tardigrades when they could dig in and push off with their claws. So for the rest of the experiments, the tardigrades trotted over gel that yielded to their claw pressure, according to the study. 

Unlike bigger animals that can be prodded into walking or running, tardigrades are too small for researchers to prompt their movement, Nirody said. So the scientists set up microscopes and cameras in the lab, let the tardigrades loose ... and then waited. 

"You get hours and hours of footage," Nirody said. "And I watched all of it."

Slow steppers

The phylum name Tardigrada (tardigrades are the sole member) comes from the Latin "tardigradus," or "slowly stepping," and tardigrades in the study lived up to that name. When moving at a leisurely pace, they traveled about half their body length per second — approximately 0.01 inches (0.25 mm) — and at faster speeds, they covered about two body lengths per second.

And when the tardigrades shifted gears between slow and fast walking, they smoothly transitioned to a new step pattern, as many arthropods do, rather than shifting into a new gait — in which the body's center of gravity also changes — as is common in animals with backbones.

When arthropods (and tardigrades) walk slowly, they lift one foot at a time. As they speed up, they lift two feet that are diagonal from each other across the body. Faster speeds make the animals shift to a new pattern in which three feet are off the ground at once: a front foot and a back foot on one side of the body, and a foot in the middle on the other side. 

"These patterns are tightly regulated by speed, they transition nicely between five legs on the ground, four legs on the ground, and then three legs on the ground as they get faster," Nirody said. And in the experiments, the tardigrades demonstrated that they followed the same pattern of which legs were airborne when other legs were on the ground.

But why do tardigrades walk like arthropods? It could be that the groups share a common ancestor that was wired to walk this way. However, it's also possible that arthropods and tardigrades evolved this stepping pattern independently, after their lineages diverged, according to the study.

"What that means is that despite having completely different body structures, body sizes and environments that they're moving through, there's something about this particular coordination scheme that's efficient across all of these conditions," Nirody said. 

Originally published on Live Science.

Chubby, resilient tardigrades — arguably the cutest of all microscopic life — can survive punishing temperature extremes, exposure to the vacuum of space and even being shot out of a gun.

But there's one thing tardigrades can't do: see in color.

Tardigrades are related to arthropods (invertebrates with segmented bodies and exoskeletons), and arthropods can see colors because of light-sensitive proteins called opsins, which play a role in vision and circadian rhythms. Tardigrades have opsins too, but little was known about what they do, so scientists recently conducted genetic analysis in two species of tardigrades, to discover how opsins affected sight in these rotund little moss piglets. 

Related: 8 reasons why we love tardigrades

"In general, vision in tardigrades is not particularly well understood," said study lead author James Fleming, a postdoctoral fellow at the University of Oslo's Natural History Museum in Norway. Scientists have previously analyzed tardigrades' eyespots, which are simple structures made of only a handful of cells (though some species are eyeless) and have tested how those tardigrades responded to light, Fleming told Live Science in an email.

"Their visual response really varies from 'directly moves away from dark towards light or vice versa' to 'begins to move when exposed to light, trying to search for a place that is not light,'" he said. Tardigrade eyes have no lenses, which suggests that they can't form images. That means their response to light "might be more directional, or intensity-based rather than image- or space-based," Fleming said. 

In the animal group Ecdysozoa — "molting animals," which includes arthropods, worms such as nematodes, and tardigrades — the opsin group that's primarily associated with vision is rhabdomeric opsins, or r-opsins. Animals with color vision typically have multiple copies of these so-called visual opsins, because "each opsin responds to a specific range of wavelengths of light," Fleming said. 

"In humans, most eyes have one visual opsin that best responds to red, one to green and one to blue — the remaining colors that we see are shades and mixes of them," he said. (Color blindness can result from the absence of one or two of these opsins.) 

In 2018, Fleming and other researchers discovered that tardigrades had multiple copies of visual opsins, suggesting that tardigrades "might be able to distinguish colors," the scientists reported July 13 in the journal Genome Biology and Evolution.

From egg to adult

In the new study, the authors looked at genetic data in two tardigrade species, Hypsibius exemplaris and Ramazzottius variornatus, and went opsin-hunting in the tardigrades' transcriptomes — collections of DNA information that are transcribed as RNA, which means they will eventually be translated into proteins that serve a purpose in the body. Transcriptome analysis can tell researchers when genes are activated and when they're dormant in an organism's cells, according to the National Human Genome Research Institute in Bethesda, Maryland. 

H. exemplaris and R. variornatus both had very well-documented transcriptomes, the authors reported. They identified multiple r-opsins in tardigrades that were associated with vision, and they tracked opsin activity in the two tardigrade species during three stages of their life cycle: egg, juvenile and adult. 

Though both species had multiple copies of active visual opsins, the opsins weren't responsive to different wavelengths of light. Rather, certain visual opsins were activated in different amounts during a given life stage, the study authors reported.

Surprisingly, some of those opsins were most active when tardigrades were still eggs — not exactly a time when you'd expect tardigrades to have much use for vision at all, Fleming said.

"Like a lot of work with tardigrades, this raises loads more questions," he explained. "It suggests that tardigrades might be using some of these opsins for non-visual purposes," but what those purposes might be are unknown, Fleming said.

The scientists concluded that even though they confirmed that tardigrades had multiple visual opsins, "we find it unlikely that they are capable of color vision." However, the presence of multiple and diverse opsins in tardigrades suggests that light sensitivity could influence tardigrade behavior more than previously thought, the researchers added.

"The more we find out about these really lovely creatures, the more questions keep coming up," Fleming said. "They interact with the world around them in a way that is very different to us, and we are still adjusting the focus on our microscope to really see their environment clearly."

Originally published on Live Science.

Tiny water-dwelling  creatures called tardigrades known for their ability to survive in the most extreme environments will be subject to a series of experiments at the International Space Station to reveal the secrets of their superpowers.

The 0.02-inch (0.5 mm) eight-legged creatures, also known as water bears, were sent to the space station as part of the Cell Science-04 experiment aboard the SpaceX Dragon 22nd resupply mission on June 3.

Tardigrades inhabit almost every ecosystem on Earth, including the most extreme habitats such as the deep sea, volcanoes and the Arctic. The new experiment will put their adaptation abilities to test in space under microgravity conditions and high radiation, according to NASA.  Scientists will keep the tardigrades on the space station for four generations to see what changes take place in their DNA over time.

Related: There Are Thousands of Tardigrades on the Moon. Now What?

"We want to see what 'tricks' they [tardigrades] use to survive when they arrive in space, and, over time, what tricks their offspring are using," Thomas Boothby, assistant professor at the University of Wyoming in Laramie and principal investigator of the experiment, said in a NASA statement. "Are they the same or do they change across generations? We just don't know what to expect."

Tardigrades are already experienced space travelers. In September 2007, the European Space Agency (ESA) sent a batch of tardigrades for a 12-day space trip aboard the uncrewed FOTON-M3 spacecraft. Most of the colony survived the exposure to vacuum and cosmic rays. Some even managed to overcome solar UV radiation that can be up to 1,000 times higher in orbit than on the surface of Earth. Past experiments on Earth showed that tardigrades may produce more antioxidants — substances that slow cell damage — when faced with more radiation.  The Cell Science-04 researchers hope the experiment will  find out whether the same happens in microgravity. The scientists will also study how the stresses of spaceflight turn various tardigrade genes on and off, NASA said.

"Checking which genes are also activated or deactivated by other stresses will help pinpoint the genes that respond exclusively to spaceflight. Cell Science-04 will then test which are truly required for tardigrade adaptation and survival in this high-stress environment," NASA added.

The critters will reside in hardware called the Bioculture System, made by NASA's Ames Research Center. The hardware allows Earthbound scientists to remotely examine cultures of microscopic creatures, or cells and tissues, while adjusting the environment as they wish.

"In the long run, revealing what makes tardigrades so tolerant could lead to ways of protecting biological material, such as food and medicine from extreme temperatures, drying out, and radiation exposure, which will be invaluable for long-duration, deep-space exploration missions," NASA said. "That's superhero-size potential for the teeny tardigrade."

Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom and on Facebook. 

Tardigrades, those adorable, chubby water bears, are notoriously hardy — they may even survive an apocalypse that wipes out humanity.

But can these hardy water bears survive being shot from a gun?  New research has found that yes, these hardy critters can make it out alive, but they also have a breaking point.

The new study was inspired by uncertainty about the fate of tardigrades that were aboard Israel's Beresheet probe when it crash-landed on the moon in 2019, according to Science magazine. Had the tardigrades, also called "water bears," survived and contaminated Earth's lifeless companion?

After all, these teensy creatures, about 0.04 inches (1 millimeter) long or less, are famous for their indestructible nature. These hardy beasts can withstand pressures up to six times that of the deepest part of the ocean, extreme amounts of radiation and even the vacuum of space, Live Science previously reported. 

Related: 8 reasons why we love tardigrades

In the new study, a group of researchers at the University of Kent in the United Kingdom decided to test if tardigrades could also survive high-speed impacts. To do this, they fed the tardigrades and then "tucked them into bed" — that is, they froze the creatures into a hibernation mode called the "tun state," in which their metabolism decreased to 0.1% their normal rate, Science magazine reported. Then, the researchers fired the critters, at different speeds, out of a "two-stage light gas gun," which shoots objects at higher speeds than a typical gun.

They found that the tardigrades could survive impacts of nearly 3,000 feet per second (900 meters per second), which would result in about 1.14 gigapascals of pressure upon impact. However, the tardigrades perished at higher pressures and impact speeds.

That means that the tardigrades aboard the Beresheet probe, which would have experienced a shock pressure above that level when it crashed, would not have survived, the scientists told Science magazine. 

Even the tardigrades that did survive low- and moderate-speed impacts took longer than control samples (which were just frozen and revived from the tun state) to recover, "which suggests that a degree of internal damage has to be overcome," the authors wrote. It's not clear whether the surviving tardigrades could later reproduce, and the authors also noted that testing whether tardigrade eggs could survive being shot out of guns to later develop would also be "a fruitful area of study."

The study has implications for a theory known as panspermia, which holds that life could have traveled between worlds on meteorites after being ejected from asteroids that crashed into planets or moons. This study shows that panspermia is difficult but not impossible, the authors told Science. 

About 40% of the rocks and debris that bounce off of asteroid impacts on our planet would hit the moon at speeds low enough for tardigrades to survive, the researchers said. A similar proportion might survive a journey from Mars to its moon Phobos. Of course, these findings  apply only to tardigrades; other life-forms, such as microbes, may survive at higher impact speeds, according to Science.

The research could also have implications for detecting life on other planets, the authors said. Spacecraft that pass near the icy plumes of water worlds such as Jupiter's moon Europa and Saturn's moon Enceladus may be able to collect potential life-forms — with the same hardiness as tardigrades — from ejected plumes, without killing them.

The findings were published May 11 in the journal Astrobiology. Read more about these robust tardigrades in Science.

Originally published on Live Science.

Scientists have discovered yet another reason to be impressed with tardigrades; some of these microscopic, nearly indestructible creatures wear a glowing "shield" that protects them from ultraviolet radiation. 

Tubby tardigrades — also called moss piglets or water bears — are known for their toughness, able to withstand extreme heat, cold and pressure, as well as the vacuum of space. They can also survive exposure to levels of radiation that would kill many other life-forms.

Now, scientists have uncovered new clues about tardigrades' radiation resistance. Experiments with tardigrades in the Paramacrobiotus genus revealed that fluorescence protects them like a layer of sunscreen, transforming damaging UV rays into harmless blue light, according to a new study. 

Related: 8 reasons why we love tardigrades

Biofluorescence bathes diverse creatures in an eerie radiance. It differs from bioluminescence, which sparks light through a chemical reaction between compounds in the animal's body; think of the bioluminescent glimmer produced by fireflies, for example. 

In fluorescent animals, their glow — usually red or green — isn't the result of a chemical reaction. Rather, these animals fluoresce when molecules inside their cells absorb light particles, or photons, from invisible UV rays and emit lower-energy light in a longer wavelength. There are sea turtles with fluorescent shells and heads, and tiny orange frogs and chameleons with fluorescent bones. Jellyfish glow with fluorescent light, as do scorpions, parrots, nematodes and yes — tardigrades, said lead study author Sandeep M. Eswarappa, an assistant professor in the Department of Biochemistry at the Indian Institute of Science in Bangalore, India.

Yet little is known about how most fluorescent species use their glow. For the new study, the authors questioned if fluorescence in tardigrades might be linked to the water bears' radiation tolerance.

"Both phenomena were connected"

The scientists tested Paramacrobiotus tardigrades' UV resistance by exposing them to 15 minutes of radiation at levels high enough to kill most microorganisms. All of the Paramacrobiotus tardigrades were still alive 30 days later, while Hypsibius exemplaris tardigrades that were UV-sensitive all died within 24 hours of radiation exposure, according to the study.

"There was no difference in the survival of these two tardigrade species when they were not treated with UV radiation," Eswarappa told Live Science in an email. 

Paramacrobiotus tardigrades also glowed brightly when exposed to UV light. However, when the researchers extracted fluorescent components from Paramacrobiotus tardigrades and applied them to both H. exemplaris and the nematode Caenorhabditis elegans — which also is non-fluorescent and sensitive to UV — the two species "showed partial tolerance to UV radiation," the researchers reported.

"It was natural to think that both phenomena were connected," Eswarappa said.

Prior studies hint that biofluorescence may offer UV protection in certain corals, and researchers hunting for extraterrestrial life suggest that biofluorescence could help organisms evolve and survive on distant worlds orbiting red dwarf stars — which have a higher UV output than our sun — potentially populating planets with many varieties of luminous creatures, Live Science previously reported.

For glowing Earthbound tardigrades, fluorescence could increase their chances of surviving in habitats where the water bears are often exposed to the sun, Eswarappa said.

"UV resistance provides these tardigrades with an ability to thrive in environments with a high UV index. For example, in tropical regions," he said. 

The findings were published online Oct. 13 in the journal Biology Letters.

Originally published on Live Science.

No, tardigrades haven't colonized the sun. But a tardigrade-shaped speck on a solar mission's images recently led to some joking about the unlikely solar presence of a wee water bear.

Today (July 16), when the European Space Agency (ESA) and NASA unveiled the latest images captured by the agencies' Solar Orbiter mission, some sharp-eyed viewers were quick to point out a small, dark blotch on the left-hand side in one of the image sequences. David Berghmans, a principal investigator for the Solar Orbiter and Head of Scientific Service Solar Influences Data Analysis Center at the Royal Observatory of Belgium, noted during a news conference that the blob resembled a tardigrade: tubby, eight-limbed microscopic animals that are known for their indestructibility.

But the dark blob was actually an image flaw that happened to have a tardigrade-like shape, Berghmans explained.

Related: 8 reasons why we love tardigrades

Solar Orbiter launched in February, carrying imaging equipment to capture views of our nearest star that will zoom in closer than any seen before, Live Science sister site Space.com reported. The mission's first images have already revealed intriguing new solar features, which gobsmacked scientists have nicknamed with "crazy names" such as "campfires and dark fibrils and ghosts," Berghmans said at the news conference.  

And when Solar Orbiter researchers spotted an oval shape that appeared to be "crawling" over some of the images, they referred to it as "a little tardigrade" and "our extra biology experiment," Berghmans said. 

"But in fact, it's a sensor defect," he said. "In future processing when we further optimize this, this will be cleaned up and interpolated from nearby pixels. But for the moment, it's still clearly visible." 

The "tardigrade" looks like it's moving because the original images were "a bit shaky," which the researchers corrected with software. But after that correction, fixed parts of the image — such as defects in the detector — started moving independently, which is why the tardigrade appeared to crawl, Berghmans said. 

On Twitter, Jack Jenkins, a postdoctoral researcher studying solar prominences at Katholieke Universiteit Leuven in Belgium, mentioned the tardigrade "hitchhiker," suggesting that the Solar Orbiter mission adopt the water bear as a mascot (mission representatives had not replied to the tweet by the time of this story's publication).

Tardigrades are unexpectedly hardy for such small creatures. They can resist extreme cold and heat; they survive exposure to radiation, crushing pressure and the vacuum of space; and they can revive after spending years in a dried-out form known as a tun state.

Despite their hardiness, not even tardigrades could survive a close encounter with the sun, where surface temperatures can reach 10,000 degrees Fahrenheit (5,500 degrees Celsius). However, tardigrades have been sent to the moon — and some tardigrades may still be there right now. On April 11, 2019, the Israeli lunar lander Beresheet crashed on the moon, possibly scattering a payload that included thousands of tardigrades in a tun state. 

But whether any of those dried-out tardigrades survived the crash remains unknown, Live Science previously reported.

Originally published on Live Science.

If humanity is ever going to settle down on Mars, we may need to become a little less human.

Crewed missions to Mars, which NASA wants to start flying in the 2030s, will be tough on astronauts, exposing them to high radiation loads, bone-wasting microgravity and other hazards for several years at a time. But these pioneers should still be able to make it back to Earth in relatively good nick, agency officials have said.

It might be a different story for those who choose not to come home, however. If we want to stay safe and healthy while living permanently on Mars, or any other world beyond our home planet, we may need to make some tweaks to our species' basic blueprint, experts say.

Related: Space radiation threat to astronauts explained (infographic)

Genetic engineering and other advanced technologies "may need to come into play if people want to live and work and thrive, and establish their family, and stay on Mars," Kennda Lynch, an astrobiologist and geomicrobiologist at the Lunar and Planetary Institute in Houston, said on May 12 during a webinar hosted by the New York Academy of Sciences called "Alienating Mars: Challenges of Space Colonization." 

"That's when these kinds of technologies might be critical or necessary," she said.

Coming soon?

Genetic enhancement may not be restricted to the pages of sci-fi novels for much longer. For example, scientists have already inserted genes from tardigrades — tiny, adorable and famously tough animals that can survive the vacuum of space — into human cells in the laboratory. The engineered cells exhibited a greater resistance to radiation than their normal counterparts, said fellow webinar participant Christopher Mason, a geneticist at Weill Cornell Medicine, the medical school of Cornell University in New York City.

NASA and other space agencies already take measures to protect their astronauts physically, via spacecraft shielding, and pharmacologically via a variety of medicines. So, it's not a huge conceptual leap to consider protecting them genetically as well, provided that these measures are proven to be safe, Mason said.

"And are we maybe ethically bound to do so?" he said during the webinar. "I think if it's a long enough mission, you might have to do something, assuming it's safe, which we can't say yet."

Tardigrades and "extremophile" microbes, such as the radiation-resistant bacterium Deinococcus radiodurans, "are a great, basically natural reservoir of amazing traits and talents in biology," added Mason, who has been studying the effects of long-term spaceflight on NASA astronaut Scott Kelly. (Kelly spent nearly a year aboard the International Space Station in 2015 and 2016.) "Maybe we use some of them."

Harnessing these traits might also someday allow astronauts to journey farther than Mars, out to some even more exotic and dangerous cosmic locales. For instance, a crewed journey to the Jupiter moon Europa, which harbors a huge ocean beneath its icy shell, is out of the question at the moment. In addition to being very cold, Europa lies in the heart of Jupiter's powerful radiation belts.

"If we ever get there, those are the cases where the human body would be almost completely fried by the amount of radiation," Mason said. "There, it would be certain death unless you did something, including every kind of shielding you could possibly provide."

Genetic engineering at least lets us consider the possibility of sending astronauts to Europa, which is widely regarded as one of the solar system's best bets to harbor alien life. (The Jovian satellite is a high priority for NASA's robotic program of planetary exploration. In the mid-2020s, the agency will launch a mission called Europa Clipper, which will assess the moon's habitability during dozens of flybys. And Congress has ordered NASA to develop a robotic Europa lander as well, though this remains a concept mission at the moment.)

Related: The 6 most likely places to find alien life

Not just us

Genetic engineering almost certainly won't be restricted to pioneering astronauts and colonists. Recent advances in synthetic biology herald a future in which "designer microbes" help colonists establish a foothold on the Red Planet, Lynch said.

"These are some of the things that we can actually do to help us make things we need, help us make materials to build our habitats," she said. "And these are a lot of things that scientists are researching right now — to create these kinds of things for our trip to Mars."

Some researchers and exploration advocates have even suggested using designer microbes to terraform Mars, turning it into a world much more comfortable for humans. This possibility obviously raises big ethical questions, especially considering that Mars may have hosted life in the ancient past and might still host it today, in subsurface lakes or aquifers. (Permanently changing our own genomes for radiation protection or any other reason may also strike some folks as ethically dubious, of course.)

Most astrobiologists argue against terraforming Mars, stressing that we don't want to snuff out or fundamentally alter a native ecosystem that may have arisen on the Red Planet. That would be both unethical and unscientific, Lynch said.

After all, she said, one of the main reasons we're exploring Mars is to determine if Earth is the only world to host life. 

"And how can we do that if we go and change the planet before we go and find out if life actually was living there?" Lynch said.

• How to feed a Mars colony of 1 million people
• How living on Mars could challenge colonists (infographic)
• By the numbers: Astronaut Scott Kelly's year-in-space mission

Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook. 

An image of a tardigrade with a psychedelic light show in its guts took home a top prize in an international photo competition. Inside the microscopic and endearingly tubby "water bear," tiny internal and external structures are illuminated in brilliant fluorescent colors that glow like a disco dance floor.

The photo was captured by Tagide deCarvalho, manager of the Keith Porter Imaging Facility (KPIF) at the University of Maryland, Baltimore County, and it was a regional winner in the 2019 Olympus Image of the Year Award, contest representatives said in a statement.

Every year, the competition awards "the best in life science imaging worldwide," celebrating images that combine visual impact and artistic beauty while also demonstrating the photographer's proficiency with microscopy, according to the statement.

Related: Magnificent microphotography: 50 tiny wonders

"I knew the moment I saw this colorful specimen that it was going to be a remarkable image," deCarvalho said. "I love sharing the fascinating things I see in the microscope with other people."

Peer at a tardigrade through a microscope and you won't see much color, as these tiny creatures are mostly transparent. However, multiple fluorescent stains helped deCarvalho create an image that was not only infused with color, but also highlighted the tardigrade's organs, she said in a statement.

"I'm excited about this image because the fluorescent dyes I used allow you to see the tardigrade digestive tract, including the mouthparts and stomach filled with food," she explained.

While the tardigrade took home the top regional prize for the Americas, the contest's pick for Global Image of the Year went to an image that was even more colorful: a fluorescent-stained photo of a mouse brain slice, captured by Ainara Pintor, a doctoral candidate in biomedicine and molecular biology at the Basque Center for Biophysics in Spain.

"There are over 70 million neurons in a mouse brain," Pintor said in a statement. "This is an example of what we can observe in the hippocampus of a single brain slice." In the image, neurons are green, cell nuclei show up as blue, and fat-associated proteins are red, according to a photo description.

Other winning images of the year portray: a wasp's ovary and eggs; crystals in a beetle's wing case; fluorescent flower buds; and a magnified view of a green opal that resembles an aerial perspective of ocean waves crashing on a rocky coastline.

You can see all of the winners on the Olympus Image of the Year 2019 website. 

• Tiny life revealed in stunning microscope photos
• Award-winning microscope images
• Amazing look at fruit fly eye (photo)

Originally published on Live Science.

Tiny-but-tough tardigrades aren't as indestructible as previously believed. 

These microanimals, which live in both fresh and salt water, are famous for their ability to survive extremes that would kill other organisms. But new research finds that the creatures rapidly wilt under heat. Water temperatures of about 100 degrees Fahrenheit (37.8 degrees Celsius) can kill tardigrades in only a day. As global temperatures rise, that could become a problem for these animals, the authors of the new study said. 

"Tardigrades are definitely not the almost-indestructible organism as advertised in so many popular science websites," said Ricardo C. Neves, a postdoctoral scientist in biology at the University of Copenhagen, who co-authored the new paper on tardigrade toughness, published Jan. 9 in the journal Scientific Reports.

Related: 8 Reasons Why We Love Tardigrades

The limits of tardigrades

Tardigrades are well-loved among science enthusiasts for their oddly adorable appearance. They have plump bodies and four sets of stubby legs. This cuteness has earned tardigrades the nicknames "water bears" and "moss piglets." Most species measure less than 0.02 inches (0.5 millimeters) in length. 

They're also survivors. Tardigrades can handle being frozen, dried out, deprived of oxygen and blasted with radiation — they've even survived trips into the vacuum of space. The critters do this by going into what's called a "tun" state. They draw in their limbs and contract their bodies, suspending their metabolism and essentially entering a state of suspended animation. There may even be tardigrades in this tun state on the moon right now, after a crash landing by an Israeli lunar probe likely sent some specimens scattering. 

Previous research found that tardigrades could even survive being boiled at up to 303.8 F (151 C) for an hour, Neves told Live Science. But no one had studied how tardigrades handle heat for longer periods. That's what Neves and his colleagues set out to do. 

Related: How Long Do Tardigrades Live?

Their methods were simple. The research team exposed tardigrades of the freshwater species Ramazzottius varieornatus to temperatures of up to 104 F (40 C) in increments of 2, 24 or 48 hours. The tardigrades were in either an active or a tun state. Researchers also tested the the creatures' survival when the temperature increase was gradual rather than immediate, exposing some of the tardigrades to acclimation periods of 2 hours at 86 F (30 C) and then 2 hours at 95 F (35 C). 

The result? Too long in the heat wasn't great for tardigrade health and happiness. After 48 hours at 104 F, all tardigrades in the active state died. At 98.6 F (37 C), about 46% of the active tardigrades died within 48 hours. Acclimation helped, though. Active tardigrades that went through the acclimation steps had a 72% survival rate at 48 hours, meaning just 28% died.

Heating up

Using a benchmark of a 50% death rate, the researchers found that it takes 48 hours at 98.8 F (37.1 C) to kill half of active tardigrades that haven't been acclimated to heat. Acclimation boosted the temperature needed to kill half of active tardigrades to 99.7 F (37.6 C). 

Tardigrades in the tun state fared a bit better, tolerating higher temperatures. It took heating to 180.9 F (82.7 C) to kill half of tun-state tardigrades within 1 hour. Longer exposure time decreased the temperature needed for lethality, though. For 24 hours of exposure, 145.6 F (63.1 C) was enough to kill half of the tun-state tardigrades.

"At the end of our study, we were quite surprised to see our results, because we expected the tardigrades — both in their active state and desiccated state — to survive higher temperatures, which was clearly not the case," Neves said. "We had found their Achilles' heel."

This Achilles' heel is troubling, Neves said, because it undermines the belief that tardigrades will survive anything, even nearby supernovas or life-destroying asteroid impacts.

"The fact that the median lethal temperature for active Ramazzottius varieornatus is so close to the currently measured maximum temperature in Denmark (i.e., 36.4 degrees C [97.5 F]) — where the specimens used in this study have been sampled — is quite worrying in our opinion," Neves wrote in an email to Live Science. 

But the tardigrades' future is still uncertain, he added. The laboratory experiments showed that the animals are capable of acclimating to temperature increases to some extent, so the rate of warming and the ability of tardigrades to adapt will probably decide their fate. Another question, Neves said, is how well marine tardigrades, not just freshwater species, will respond to hotter waters as the globe warms.

• Extreme Life on Earth: 8 Bizarre Creatures 
• The Best Gifts for Tardigrade Lovers
• In Photos: The World's Freakiest-Looking Animals

Editor's Note: This article was updated to clarify the temperature range at which tardigrades cannot survive. 

Originally published on Live Science.

The world saw plenty of sad, angry and downright catastrophic news this year. But a river of heartwarming, amazing discoveries also flooded in this year, from tardigrades on the moon (lunar water bears?!) to jewel-like lakes under Greenland to a trippy wonderland of hydrothermal vents. Here’s a look at the gems science turned up in 2019.

How we got showered in gold

Astronomers this year calculated that a single merger between two neutron stars could have showered our solar system with millions of pounds of precious metals like gold and platinum. It would have happened about 100 million years before the solar system formed during a collision of the ultradense corpses of giant stars that ended their lives in explosive events. The merger, they estimated, happened about 1,000 light-years from us. And if you’re wearing a gold or platinum ring, you carry a bit of this explosive past on your hand, the researchers said.

Lunar tardigrades?! 

Thousands of tardigrades landed on the moon this year. These were not astronaut-suit-wearing water bears, however. Rather, the microscopic beasties crashed onto the surface during a failed landing attempt on April 11 by the Israel spacecraft called Beresheet. The tardigrades were in a tun state, meaning they were dehydrated, with metabolic activity suspended. While the tardigrades may have survived the crash landing, they’d need water to come back to life, so there’s little chance of tardigrades colonizing our moon — but picturing the chubby guys roaming around is a cheery thought.

Trippy wonderland discovered

As if Dr. Seuss created this undersea wonderland, deep in the Gulf of California lies a fantastical expanse of hydrothermal vents, scientists discovered this year. They found glimmering pools of piping-hot fluids, rainbow-hued life-forms and towering mineral structures rising some 75 feet (23 meters) from the seafloor. The researchers who discovered the system said that it seems to have built up over the past 10 years as hydrothermal venting, where mineral-laden water jets out from the seafloor, ramped up. Speaking about the discovery in April, team leader Mandy Joye of the University of Georgia said: "Astonishing is not strong enough of a word."

Ninja rat drop-kicks rattlesnake

An epic slow-motion video released this year revealed some crazy acrobatics in the wild. In a feat that would put Bruce Lee to shame, a kangaroo rat — Ninja Rat — drop-kicks a deadly rattlesnake in a blindingly fast motion. In fact, the researchers studying these videos found that kangaroo rats could react to a snake attack in as little as 38 milliseconds. In some instances, they would leap clear of the snake in just 70 milliseconds. 

Baby T. rex was adorable ball of fluff

One may not be able to help but smile a this baby T. rex covered in fluff. RAWR! The tyrannical beast wasn’t always so formidable; T. rex hatchlings broke from their egg at about turkey-size, though skinnier and covered in a coat of downy feathers, according to reconstructions that represent the most accurate models of what the dinosaur would have looked like. This fluffball and other dino surprises were unveiled in March at the exhibit "T. rex: The Ultimate Predator," which opened at the American Museum of Natural History (AMNH) in New York City.

HEART-warming blue whale?

For the first time ever, scientists recorded the heartbeat of the world's largest creature to ever liver: the blue whale. And it turns out, the behemoth can survive on just two heartbeats a minute. The researchers suction-cupped a pulse monitor to the back of a blue whale off California and then proceeded to watch the beast dive and resurface over 9 hours. During these meal-searching dives, the whale's heart pumped as many as 34 times per minute at the surface and as few as just two at the deepest depths. Did your heart skip a beat?

Antarctic lake of bubbling lava

Just about everything found in Antarctica is pretty amazing. This year's discovery of a huge lake of sizzling hot lava there was no exception. On a remote sub-Antarctic island in the South Atlantic Ocean, scientists discovered what is now only the eighth lake of molten rock ever identified. They found this bubbling cauldron of sorts inside the crater of the volcano Mount Michael on Saunders Island. The molten rock, which rises between 300 and 700 feet (90 and 215 meters), reaches a whopping 1,812 to 2,334 degrees Fahrenheit (989 to 1,279 degrees Celsius), the researchers found.

Giant squid filmed alive

The elusive, giant squid generally comes out of hiding only after the creature is dead and washes up on some beach. That's what made this year's "catch" so exciting: Scientists captured video of the eight-legged creature, in the genus Architeuthis, deep in the Gulf of Mexico, revealing the graceful creature as it approaches blinking lights on a decoy crafted to look like a bioluminescent jellyfish. The encounter is a fast one: As soon as the squid realizes the lights are coming from a non-jellyfish object, it darts away. But it did stay long enough to reveal the awe and wonder of the deep sea.

The gorgeous and befuddling Hoag's Object

Perhaps one of the most gorgeous, and befuddling, objects in the cosmos, this galaxy within a galaxy within a galaxy slithers through the northern sky. A stunning image captured by the Hubble Space Telescope and processed by geophysicist Benoit Blanco this year shows Hoag's Object — which spans 100,000 light-years across — glistening in the serpent constellation, with a billions of blue stars forming a perfect circle around a much smaller and denser orb of reddish stars; that's not all, lurking in the gap between these star circles is another ring galaxy that's much farther away from us. 

Keeping Schrödinger's cat alive

What if physicists could both peek at the enigmatic Schrödinger's Cat while also keeping the famous feline alive? That's just what physicists sort of figured out this year after studying the feline-based thought experiment in which an unlucky, imaginary cat is both alive and dead inside a box (in a state of superposition in terms of quantum particles). Once the owner looks inside the box, that cat's fate is sealed, so the idea goes. In a new study, scientists figure out an ingenious way to separate that initial interaction (peeking at the cat) from the result (knowing whether it's alive or dead). Keeping a furry four-legged creature alive, one that seemed doomed to living in the unknown, is pretty amazing. Plus, it advances "scientists' understanding of one of the most fundamental paradoxes in physics," Live Science reported in November.

Diamond inside a diamond

This is not your average diamond. Scientists declared this year that a diamond extracted from a mine in Yakutia, Russia, was holding a sparkly surprise: another diamond. The smaller diamond was rattling around in an air pocket at the center of the larger stone, Russian experts who examined the gemstones said. The diamond-in-a-diamond is estimated to be about 800 million years old. 

In fact, it's now considered the only known examples of such a dynamic duo. "I have no knowledge of anything like this in the natural mineral world," George Harlow, a curator in the Department of Earth and Planetary Sciences at the American Museum of Natural History in New York City, told Live Science in an email. 

Jewels under Greenland

There are gems under Greenland's ice sheet. Though not actual gemstones, 56 sparkly blue, oddly shaped lakes were discovered this year. The discovery brings the known subglacial lakes in Greenland to 60. The lakes range from tiny — just 656 feet (200 meters) long — to enormous — stretching some 3.6 miles (5.9 kilometers) in length. And life could be hiding in this under-ice bodies of water, the extreme kind. 

"These lakes could provide important targets for direct exploration to look for evidence of extreme life," study co-researcher Stephen Livingstone, a senior lecturer in physical geography at the University of Sheffield in the United Kingdom, said in a statement.

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Originally published on Live Science.

Will we one day combine tardigrade DNA with our cells to go to Mars? 

Chris Mason, a geneticist and associate professor of physiology and biophysics at Weill Cornell University in New York, has investigated the genetic effects of spaceflight and how humans might overcome these challenges to expand our species farther into the solar system. One of the (strangest) ways that we might protect future astronauts on missions to places like Mars, Mason said, might involve the DNA of tardigrades, tiny micro-animals that can survive the most extreme conditions, even the vacuum of space! 

Mason led one of the 10 teams of researchers NASA chose to study twin astronauts Mark and Scott Kelly. After launching in 2015, Scott Kelly spent almost a year aboard the International Space Station while his twin brother, Mark Kelly, stayed back on Earth. 

Related: By the Numbers: Astronaut Scott Kelly's Year-in-Space Mission 

By comparing how they biologically reacted to their vastly different environments during that time, scientists aimed to learn more about how long-duration missions affects the human body. Mason and the dozens of other researchers who worked to assess the genetic effects of spaceflight uncovered a wealth of data that has so far revealed many new findings about how space affects the human body. 

Researchers hope that this work, which continues today, might inform strategies to support astronaut health on future missions. Mason discussed some of the results of this research at a talk at the 8th Human Genetics in NYC Conference on Oct. 29. 

In addition to the research Mason discussed at the conference, these researchers are working on seven more papers incorporating the data from the twins study. However, they also hope to use new data from a larger sample.

"We want to do some of the same studies, longitudinal studies, with people on Earth, people in space," Mason told Space.com at the conference.

Mitigating the effects

By studying, specifically, how certain genes are expressed during the different stages of spaceflight (including the intense return to Earth), these research efforts could support future efforts to mitigate the dangers of spaceflight, Mason said. 

For instance, if further studies were to confirm that landing back on Earth were harmful to the human body, scientists could develop ways to prevent those detrimental effects. But with such a small body of data (the twins study was just two people), scientists aren't ready to prescribe any specific treatment or preventative medicine to alter how humans genetically react to spaceflight. 

"I think we do what is normally done in science … We see something interesting; let's try it in mice first," Mason said. 

He noted that they might not even find it necessary to prescribe anything to alter the effects they've seen in astronauts like Scott Kelly. "Some of those changes, even though they're dramatic, maybe that's how the body needed to respond," Mason said. 

Related: Space Radiation Threat to Astronauts Explained (Infographic)

Future astronauts and tardigrade DNA

While, Mason noted, future astronauts might be prescribed medicine or other tools to help to mitigate the effects which they've uncovered with this research. However, new studies are investigating how tools such as gene editing could make humans more capable of traveling farther into space and even to planets such as Mars. 

One of the main health concerns with space travel is radiation exposure. If, for example, scientists could figure out a way to make human cells more resilient to the effects of radiation, astronauts could remain healthier for longer durations in space. Theoretically, this type of technology could also be used to combat the effects of radiation on healthy cells during cancer treatments on Earth, Mason noted. 

However, the idea of tinkering with human genes is controversial. But Mason emphasized that there will likely be decades of research completed before this kind of science is applied to humans. 

"I don't have any plans of having engineered astronauts in the next one to two decades," Mason said. "If we have another 20 years of pure discovery and mapping and functional validation of what we think we know, maybe by 20 years from now, I'm hoping we could be at the stage where we would be able to say we can make a human that could be better surviving on Mars." 

But what does it mean to genetically engineer a person to better survive in space or on another planet? There are multiple possible approaches.  

One way that scientists could alter future astronauts is through epigenetic engineering, which essentially means that they would "turn on or off" the expression of specific genes, Mason explained

Alternatively, and even more strangely, these researchers are exploring how to combine the DNA of other species, namely tardigrades, with human cells to make them more resistant to the harmful effects of spaceflight, like radiation.

This wild concept was explored in a 2016 paper, and Mason and his team aim to build upon that research to see if, by using the DNA of ultra-resilient tardigrades, they could protect astronauts from the harmful effects of spaceflight. 

Genetically editing humans for space travel would likely be a part of natural changes to the human physiology that could occur after living on Mars for a number of years, Mason said. "It's not if we evolve; it's when we evolve," he added.

While changes to the human body are to be expected as our species expands off-Earth, there is a way to do this science responsibly, Mason said. "In terms of a question of liberty, you're engineering it [a future human] to have lots more opportunities, again assuming we haven't taken away opportunities," he said. "If we learned that, in some way, when we decided to try and prove the ability of humans to live beyond Earth, and we take away their ability to live on Earth, I think that would be unjust."

Genetically engineering humans could be ethical if it makes people more capable of inhabiting Mars safely without interfering with their ability to live on Earth, Mason said. 

• Twins In Space: Astronauts Mark and Scott Kelly in Photos
• By the Numbers: Astronaut Scott Kelly's Year-in-Space Mission
• How 1-Year Space Mission Affected Astronaut Twin Scott Kelly: Early Results

Follow Chelsea Gohd on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.

If you can't get enough of tardigrades — those tough, tubby microscopic critters with eight squirmy legs — you'll love this newly discovered microinvertebrate. 

Behold, the "mold pig."

Discovered by paleobiologist and entomologist George Poinar Jr. of Oregon State University, mold pigs earned the nickname thanks to their fungi-heavy diet and vague resemblance to hogs, according to a statement released yesterday (Oct. 8). Only 0.003 inches (100 micrometers) long, the creatures boast four pairs of teensy legs, a flexible head and an exoskeleton that molts as they grow. The tiny swines' proposed scientific name, Sialomorpha dominicana, derives from words meaning "fat hog-shaped" in Greek. 

"The mold pigs can't be placed in any group of currently existing invertebrates — they share characteristics with both tardigrades, sometimes referred to as water bears or moss pigs, and mites but clearly belong to neither group," Poinar said in the statement.  

Poinar may be best known as the paleobiologist who inspired a major plot point in author Michael Crichton's signature novel, "Jurassic Park," according to Science Friday. Poinar and electron-microscopist Roberta Hess (Poinar's wife) discovered that organisms can be immaculately preserved in amber, the fossilized resin of ancient coniferous trees. Within the yellowish substance, an organism's cellular machinery can remain largely intact over the course of millennia. 

Related: Ancient Footprints to Tiny 'Vampires': 8 Rare and Unusual Fossils

Inspired by this finding, Crichton dreamt up a world where dinosaurs could be summoned from DNA encased in amber.   

Back in reality, Poinar never stopped digging for and discovering new organisms hidden in ancient resin. Recently, he and his colleague Diane Nelson of East Tennessee State University came upon several hundred mold pig fossils coated in amber from the Dominican Republic. The specimens date back to the mid-Tertiary period, about 30 million years ago, and would have shared their habitat with pseudoscorpions, nematodes, protozoa and fungi, the authors said.  

"The large number of fossils provided additional evidence of their biology, including reproductive behavior, developmental stages and food," Poinar said. The creatures mostly fed on fungi but also ate some small invertebrates, the researchers found. Although mold pigs may resemble tardigrades at first glance, they represent a previously unknown new family, genus and species of microinvertebrate, according to Poinar. He and Nelson described their discovery in a paper published Sept. 28 in the journal Invertebrate Biology.  

"Based on what we know about extant and extinct microinvertebrates, S. dominicana appears to represent a new phylum," Poinar said. "But we don't know when the Sialomorpha lineage originated, how long it lasted, or whether there are descendants living today." 

• 8 Reasons Why We Love Tardigrades 
• Photos: Ancient Ants & Termites Locked in Amber 
• Tiny Grandeur: Stunning Photos of the Very Small 

Originally published on Live Science. 

Scientists recently deciphered a key ingredient in tardigrades' arsenal of superpowers, unraveling how a unique protein in everyone's favorite microscopic water bears acts as a barrier against harmful radiation.

Though tiny, tardigrades are notoriously tough. They can weather extreme conditions that would kill most forms of life, including exposure to freezing cold, broiling heat, and the vacuum and lethal radiation of space.

But what are the chemical secrets that lend tardigrades their near-invulnerability? To answer that question, researchers peered closely at a compound found only in tardigrades: the so-called damage-suppressor protein, or Dsup. 

This protein's protective powers were previously found to extend beyond tardigrades; when added to human cells, Dsup safeguards against damage from X-rays. And now, scientists have discovered how Dsup binds to chromosome structures and protects DNA from the harmful effects of radiation, the researchers reported in a new study.

Related: 8 Reasons Why We Love Tardigrades

"We thought this fascinating protein in an extreme organism might tell us something new that we wouldn't get from regular proteins," said study co-author James Kadonaga, a professor with the Division of Biological Sciences at the University of California, San Diego.

Though tardigrades may seem indestructible, they require water in order to be active and reproduce. In water's absence, they retreat into a form of suspended animation called a tun state, expelling moisture from their bodies and existing in a desiccated limbo until more-hospitable conditions return. 

As tuns, tardigrades are impervious to most forms of harm and can even be revived after decades, possibly even after spending time on the moon. Thousands of tuns may have been scattered on the lunar surface after the Israeli lunar lander Beresheet (which was carrying a payload of desiccated water bears) crashed on April 11 during a failed landing attempt. Under certain conditions, if they survived the crash landing, those freeze-dried tardigrades could still come back to life, Live Science previously reported.

Seemingly indestructible

Some of the proteins that allow tardigrades to revive after being dried out are found in other organisms, but Dsup is exclusive to water bears. And while prior studies found that this protein made human cells resistant to X-ray radiation, the mechanisms of how Dsup did that were uncertain. 

In the new study, the researchers discovered that Dsup binds to a structure called chromatin, a package that holds a cell's long strands of DNA in a dense package, Kadonaga told Live Science. 

"We found it binds to chromatin. Then we asked, 'How does it make it resistant to X-rays?'" he said.

When cells are bathed in X-rays, water molecules split and form highly reactive particles  of oxygen and hydrogen called hydroxyl radicals; these radicals can damage DNA inside cells, according to the study. 

"We thought, 'Why don't we just see if Dsup can protect DNA from hydroxyl radicals?' And the answer is yes, it can," Kadonaga explained. High-energy Dsup has a cloud-like structure; the cloud surrounds the DNA's chromatin envelope, blocking hydroxyl radicals and preventing them from disrupting cellular DNA, the researchers reported.

"Now that we know how it worked, that's a stepping stone to potentially using it for practical applications," Kadonaga said.

By piecing together how Dsup functions at ever-more-precise levels, scientists can then use it as a blueprint for building other types of proteins — "better versions of Dsup" — that are even more effective at protecting cells from DNA damage, Kadonaga said. These new proteins probably won't be used to produce radiation-proof people, but they could improve the hardiness of cultured cells that are used for growing pharmaceuticals, he added.

"You can have more-durable cells, more-longer-lived cells. That might be a case for putting some form of Dsup in that cell," he said.

The findings were published online Tuesday (Oct. 1) in the journal eLife.

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Originally published on Live Science.

Tardigrades, which live on every continent on Earth, are also (maybe) living on the moon, following the crash of a lunar lander carrying thousands of the microscopic water bears.

Did any of them survive the impact? If they did, what happens to them now?

When the tardigrades were placed on the Israeli moon mission Beresheet, they were in a tun state — dehydrated, with their chubby limbs and heads retracted and all metabolic activity temporarily suspended. Their arrival on the moon was unexpectedly explosive; Beresheet's crash landing on April 11 may have scattered the microorganisms onto the lunar surface. 

Tubby tardigrades are notoriously tough, but were the Beresheet tardigrades hardy enough to survive that impact? It's certainly possible that some of them made it to the moon intact. But what would that mean for the moon to have what might be thousands of Earth microbes as new inhabitants? And what might it mean for the tardigrades?

Related: 8 Reasons Why We Love Tardigrades

First of all, is anyone in trouble for accidentally spilling tardigrades on the moon? That's a complicated question, but the short answer is no. Space agencies from around the world follow a decades-old treaty about what is permissible to leave on the moon, and the only explicit prohibitions are against weapons and experiments or tools that could interfere with missions from other agencies, according to the 1967 Outer Space Treaty.

In the decades that followed the treaty, other guidelines were created that acknowledged the risks of seeding other worlds with Earth microbes, and these stipulations outlined practices for sterilizing mission equipment to avoid contamination. But even though large space agencies typically follow these rules, there is no single entity enforcing them globally, Live Science previously reported.

Scientists have yet to find any evidence that the moon ever hosted living organisms (other than visiting astronauts and microbial hitchhikers from Earth) that could be threatened by microscopic invaders. However, contamination could carry serious consequences for missions to planets where life might yet be found, such as Mars; experts suggest that one potential consequence of colonizing Mars could be the extermination of native microbial life through exposure to Earth bacteria.

It's possible that even before the Beresheet tardigrades crashed on the moon, other forms of terrestrial microbes were already there: gut bacteria in abandoned bags of astronaut poo, said Mark Martin, an associate professor of biology at the University of Puget Sound in Tacoma, Washington.

"I'd be very surprised if you couldn't culture a few things out of the center of that freeze-dried material," Martin told Live Science. "Especially spore-formers. They make a very thick outer layer of their spore proteins that's known to protect them against dehydration, radiation — a variety of things."

Sole survivor 

Tardigrades survive conditions that would destroy most other organisms; they do so by expelling the water from their bodies and generating compounds that seal and protect the structure of their cells. The creatures can remain in this so-called tun state for months and still revive in the presence of water; scientists even resuscitated two tardigrades from a 30-year deep freeze in 2016.

As a tun, a tardigrade can weather boiling, freezing, high pressure and even the vacuum of space, the European Space Agency (ESA) reported in 2008, after sending water bears into orbit. Ultraviolet radiation turned out to be the tardigrades' kryptonite, as few of the creatures survived full exposure to UV light during the ESA experiments.

This could be good news for the desiccated Beresheet tardigrades. If they landed in a spot on the moon shielded from UV radiation, the microscopic creatures might stand a chance of survival, Martin said.

"My guess is that if we went up in the next year or so, recovered the wreckage, and found these tiny, little tuns and put them in water, a few of them would come back to life," he explained. 

But as long as the tardigrades remain on the moon, their chances of spontaneously awakening are low. Without liquid water, the tiny creatures will remain in a tun state, and while there's evidence of ice on the moon, liquid water is nowhere to be found. 

Even if the lunar tardigrades did somehow encounter liquid water while still on the moon, without food, air and a moderate ambient temperature, they wouldn't last very long once they revived, Kazuharu Arakawa, a tardigrade researcher with the Institute for Advanced Biosciences at Keio University in Tokyo, told Live Science in an email.

"Much as I would love to see the establishment of the Lunar Tardigrade Republic, I don't think that's going to happen," Martin said.

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Originally published on Live Science.

When you look up at the moon, there may now be a few thousand water bears looking back at you.

The Israeli spacecraft Beresheet crashed into the moon during a failed landing attempt on April 11. In doing so, it may have strewn the lunar surface with thousands of dehydrated tardigrades, Wired reported yesterday (Aug. 5).

Beresheet was a robotic lander. Though it didn't transport astronauts, it carried human DNA samples, along with the aforementioned tardigrades and 30 million very small digitized pages of information about human society and culture. However, it's unknown if the archive — and the water bears — survived the explosive impact when Beresheet crashed, according to Wired. [8 Reasons Why We Love Tardigrades]

The tardigrades and the human DNA were late additions to the mission, added just a few weeks before Beresheet launched on Feb. 21. Much like Cretaceous fossils locked in amber, the DNA samples and tardigrades were sealed in a resin layer protecting the DVD-size lunar library, while thousands more tardigrades were poured onto the sticky tape that held the archive in place, Wired reported.

But why send tardigrades to the moon? Tardigrades, also known as moss piglets, are microscopic creatures measuring between 0.002 and 0.05 inches (0.05 to 1.2 millimeters) long. They have endearingly tubby bodies and eight legs tipped with tiny "hands"; but tardigrades are just as well-known for their near-indestructibility as they are for their unbearable cuteness.

Tardigrades can survive conditions that would be deadly to any other form of life, weathering temperature extremes of minus 328 degrees Fahrenheit (minus 200 degrees Celsius) to more than 300 F (149 C). They also handily survive exposure to the radiation and vacuum of space.

Another tardigrade superpower is their ability to dehydrate their bodies into a state known as a "tun." They retract their heads and legs, expel the water from their bodies and shrivel up into a tiny ball — and scientists have found that tardigrades can revive from this dehydrated state after 10 years or more.

In other words, if any creature were capable of surviving a crash-landing in space, it would probably be a tardigrade. Whether any of the Beresheet tardigrades are biding their time in a lunar impact crater until they can be resuscitated, only time will tell.

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Originally published on Live Science.

There are few things more wondrous than watching a tardigrade wriggle under a microscope with something weird in its belly — be it an absurdly large poo, a clutch of spaghetti-topped eggs or, as shown in a remarkable video posted to Twitter this week, a mysterious mother lode of glowing crystals.

Tardigrades — more whimsically known as water bears or moss piglets — are near-microscopic, piggly-wiggly invertebrates found on mosses and in other wet places around the world. In the brief Twitter video, biologist Rafael Martín-Ledo studied a tardigrade from the Saja river in northern Spain, using an imaging technique called phase contrast microscopy, which brightens structures that scatter higher amounts of light. The technique highlighted tricky-to-see structures, like the tardigrade's stylets — a pair of hard, food-piercing tools flanking the piglet's mouth (seen on the left side of the video) — but also revealed the surprising contents of the tardigrade's tummy. Glittering like a tiny galaxy, chunks of strange crystals filled the water bear's stomach. [8 Reasons Why We Love Tardigrades]

What are they, and how did they get there? Nobody knows. But according to Martín-Ledo — a high school science teacher in Santander, Spain, and co-author of numerous studies on marine microfauna — those gut crystals could be bits of the tardigrade's own mouth.

"The tardigrade's two stylets are made of aragonite," a common mineral made of carbon and calcium, Martín-Ledo told Live Science. "So, when I saw crystal-like elements inside its belly, I supposed they must be pieces of aragonite crystals that it swallowed."

This is just a hunch, Martín-Ledo noted. But, considering tardigrades molt and regrow their stylets from time to time, it's plausible that some bits might end up in the animals' bellies.

And, if it turns out that tardigrades do, occasionally, swallow bits of their own mouths, it would hardly be the weirdest thing about them. Structurally, tardigrades are little more than eight-legged heads with a mouth and an anus, and yet they are one of the animal kingdom's most resilient champions, capable of withstanding extreme heat, bone-chilling cold and blasts of radiation that would kill most other creatures. Some have even come-to after being frozen solid for 30 years.

With more than 1,000 known species of these puny, pudgy superheroes discovered so far, it's fair to say that Earth may be the tardigrade's world, and we're just living in it. If water bears want to eat their own faces from time to time, who are we to stop them?

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Originally published on Live Science.

The Year in Cute

2018 was a tough news year for a lot of us, but it was also a great year for the advancement of Cuteness Studies. In May, for example, scientists discovered that puppies reach peak cuteness at 6 to 8 weeks old. This is important information that will inform many lunchtime Google image searches for decades to come.

Elsewhere around the world, a donkey fell in love with an emu, a momma duck babysat 76 fluffy babies and penguins requisitioned a research camera to take selfies. Join us now for a photographic review of 2018's most adorable scientific moments. You've earned this.

A Very Smol Octopus

In 2018's top smol animal news, feast your peepers on this really, really, ridiculously tiny baby octopus.

This pea-sized cephalopod was spotted this August riding a piece of plastic litter in the ocean near Hawaii's Kaloko-Honokōhau National Historical Park. Park workers rescued the octo-baby from its debris boat, snapped a few pictures, then released it "safe and sound in a small protected space," the team wrote on Facebook. 

Smol as he is now, this little boi now has a chance to grow. While the baby is too young to identify as a precise species, similar-looking octopi can grow to have an armspan measuring up to 7 feet (2 meters). They grow up so fast!

When Penguins Pose

When you give a penguin a camera, it will try to take a selfie.

That was one of the (accidental) findings of a recent Antarctic research project, in which scientists left a live video camera perched near a rookery of emperor penguins. It didn't take long for the tuxedoed birds to find their watchers.

In the adorable footage that followed, the camera first focuses on the feet of two pudgy penguins as they waddle toward it — but the birds soon nudge the camera upward to focus on their faces. (And yes, even bird beaks look larger in selfies.) The penguins then make several vocalizations, as if to say, "Look what I found!" It turns out that even animals become a little vain when they know they're on camera (well, at least the best-dressed animals).

This Duck Supermom is Parenting Goals

One momma bird, 76 ducklings. Experts agree: That is one duckload of beaks to feed.

For what it's worth, this Minnesota supermom (dubbed 'Momma Merganser' by nature photographer Brent Cizek) definitely didn't lay all those eggs herself; mother ducks can incubate about 20 eggs at a time, ornithologist Richard Prum told The New York Times. The other ducks following momma may be enrollees in a sort of duckling day-care system called a crèche, in which female birds entrust their newborn young into the care of an older, wiser female.

This elder babysitter is usually experienced in raising young and doesn't mind taking a few hatchlings under her wing while the little tykes' parents go off to do important adult bird things, like molt their feathers. Still, while crèches of 20 or 30 ducklings are not uncommon, one bird with 76 followers is exceptional. The mystery of Momma Merganser remains one tough nut to quack.

Aye Aye, Captain!

How bizarre can a newborn look and still, somehow, be cute? Tonks the baby aye-aye may answer that question. Born at the Denver Zoo on Aug. 8, Tonks is one of only 24 of the nocturnal lemurs in captivity in the United States. She's a squirrel-size bundle of wiry fur, beady eyes and freakishly scraggly claws, and she's somehow still absolutely adorable.

Tonks is named after the "Harry Potter" character Nymphadora Tonks, a fitting moniker given that the newborn's mother is called Bellatrix, after the "Harry Potter" villain Bellatrix Lestrange. The new aye-aye's father, another Denver Zoo resident, is named Smeagol, after the dark-loving "Lord of the Rings" character. (Perhaps you can sense a theme here.)

Aye-ayes (Daubentonia madagascariensis) are native to Madagascar. No one knows precisely how many exist in the wild, but they are considered endangered. At the risk of sounding like a nosy mother-in-law, we hope Tonks carries on the family tradition of begetting healthy, literary-themed children.

The Donkey Who Loved an Emu

It was love at first… squawk-neigh?

Living on a farm in North Carolina, a donkey and emu named "Jack and Diane" have developed a deep bond with one another and appear to be in love. "They like to cuddle and even sleep together," Jennifer Gordon of the Carolina Waterfowl Rescue told The Charlotte Observer.

The Rescue discovered the unlikely couple when the farm's owner vanished in early November. When the cross-species lovers were put in separate pens, both showed signs of anger and anxiety (Jack, the donkey, reportedly started crying). They were promptly reunited — and hopefully they'll stay that way. Last we heard, the rescue team as currently looking for someone willing to adopt both a donkey and an emu. Could it be you??

When Elephants Eat Cereal

Elephants use their trunks to smell, touch and sometimes paint lovely little self-portraits. But how helpful is a trunk when it comes to eating tasty breakfast cereal?

In one of 2018's most adorable studies, scientists found out — with a lot of help from an African elephant named Kelly, who lives at Zoo Atlanta in Georgia. Researchers fed Kelly 24 plates of either chopped veggies or granular piles of bran cereal to see how the size of a meal changed the way Kelly used her trunk during feeding.

While Kelly picked up the veggies by scooping them into a tight bundle using the side of her trunk, the chalky piles of bran required a more tender approach. To eat the cereal, Kelly pressed her trunk onto the pile, pinched the tip of her trunk into a chopstick-like wedge and carried the captured pile of bran directly to her mouth. This research shows that elephant trunks are even more versatile tools than scientists previously knew — and also, elephants look really, really cute scooping up piles of treats.

The World's Punkiest Turtle

"The Mary River Turtle" would make a pretty good name for an '80s alt-rock band, but it happens to be the actual name of a tiny, green-mohawked turtle living in Australia. With whisker-like growths forking out of its chin and shocks of algae bursting off of its head like a punky green mohawk, the freshwater swimmer looks as much like an aging rocker as it does an endangered species.

Sadly, like many a rock star, this turtle is a dying breed. The rare turtle ranks 29th on a list of the world's 100 most endangered reptiles, released in April by the Zoological Society of London. One 2017 study estimated there may be as few as 136 of them left in the wild. The Zoological Society hopes to keep this number from plummeting by raising awareness of the cute, quirky creatures Earth stands to lose if habitats aren't properly protected from human encroachment.

A Brand-New Tardigrade with Spaghetti Eggs

Pinkish, pudgy and oh-so-smol, tardigrades — aka "water bears" — have a newborn baby cuteness about them that's hard to ignore, even when they're making poos half the size of their own bodies.

This year, a new species of tardigrade called Macrobiotus shonaicus was discovered in a parking lot in Japan. While it has the signature round, 8-legged body of all tardigrades, this newcomer has some of the weirder eggs researchers have seen. The spherical sacs are covered in wobbly, noodle-like filaments, possibly to help the egg attach to the surface where its laid. A new tardigrade with spaghetti eggs? We'll take it!

Tardigrades, in general, are famous for their toughness: They can survive in extreme cold (down to minus 328 degrees Fahrenheit, or minus 200 Celsius), extreme heat (more than 300 degrees F, or 149 degrees C), and even the unrelenting radiation and vacuum of space, as one 2008 study reported.

I Heard You Like Moons…

The moon is Earth's little buddy in the sky, but what if our moon had its own tiny companion to hang out with when the Earth was busy (say, during a total lunar eclipse)? We're talking about moonmoons — moons that orbit other moons.

Moonmoons (also known online as submoons, moonitos, grandmoons, moonettes and moooons) may not exist in our solar system or any other. However, according to a pair of astronomers writing in the preprint journal arXiv.org in October, the concept of a moon hosting its own mini-moon is, at least, plausible — so long as the host moon is sufficiently massive, the moonmoon is sufficiently small, and there is a wide orbital gulf between those moons and their host planet.

Whether humans will ever set foot on a moonmoon is hard to say. But if and when we do, it will truly be one (very) small step for man, and one giant leap for moonkind.

Originally published on Live Science.

They're cute, they're tiny and they're extremely resilient. Tardigrades, commonly known as "water bears" might just outlive us all. These eight-legged creatures, usually smaller than the tip of a sharpened pencil, can survive trying times by curling up into a ball and entering a near-death state called "cryptobiosis."

They can withstand extreme temperatures from as cold as negative 328 degrees Fahrenheit (minus 200 degrees Celsius) to as hot as over 300 degrees F (148.9 degrees C). They can also live through radiation, boiling liquid, extreme pressure and can even survive in space without any protection. 

But perhaps their greatest achievement is their obsessive human following. The internet is filled with tardigrade paraphernalia that just might make the perfect holiday presents for the water-bear-entranced (including yourself). Tardigrades are here, they're there, they're everywhere, take a look:

Tardigrades on your feet

Hashtag Collectibles Water Bear Slippers, $24.99

Tardigrades closer to your feet

Hashtag Collectibles water bear socks, $11.99

Tardigrades on your shirt

'Live Tiny Die Never' shirt, $15.95

Tardigrades on your skirt

Tadigrades skirt, $46.87

Available from Etsy seller Interrobangirl.

Tardigrades in your garden

Tardigrades Garden Flag, $12.99

Tardigrades on your tree

Ornament-Tardigrade water bear, $10

Available from Etsy seller CuteSci.

Tardigrades on your ears

Tardigrade earrings, $19.75 

Available from Etsy seller tcustom.

Stressed? Tardigrades can help

The Tardigrade Stress-o-Cizer, $20,

Available from Etsy seller stexe.

Bored? Crochet your own tardigrade

Tardigrade crochet pattern, $5

Available from Etsy seller hepp.

Tardigrades can hang with your keys

Tardigrade keychain, $26.75

Available from Etsy seller tcustom.

Tardigrades can hold your pins

Waterbear Pincushion, $32

Available from Etsy seller alleluja. 

Tardigrades can welcome your mail

Tardigrades in Space Custom Mailbox Covers, $12.5,

You can hug this tardigrade

Stuffed Water Bear, $39.99

You can hug this mini tardigrade

Stuffed Water Bear Plush-Mini, $14.99

Tardigrades with your wine

Biologist Tardigrade Wine Glass Gift, $15.99

Available from Etsy seller GlassCannons.

Is your baby tiny but mighty like a tardigrade?

Tardigrade Onesie, $23

Available from Etsy seller BrawnAndBrindle.

Originally published on Live Science.

Here at Live Science, our top choice for "cute animal" is the roly-poly and nearly indestructible tardigrade. Yep, we're talking about the water bear, the microscopic organism that looks more like an alien caterpillar than an Earthly animal when viewed up close.

Plenty of gorgeous shots of the tiny creatures online show their segmented, pudgy bodies; their eight legs tipped with claws; and their circular mouths in all their glory. But those images are generally shot through high-powered and advanced microscopes, and sometimes, they're even touched up afterward. That got us wondering whether an inexpensive, off-the-shelf microscope you may have used as a kid in biology class would do the trick.

What if we went out and grabbed some tardigrades and popped the little, squirming bodies under a microscope lens? Well, that's just what we did. At first, we planned to go out to a backyard and collect them from the grass and dirt; apparently, they thrive in just about any environmental conditions. But to ensure they had all their legs and other body parts, we went with "store-bought" specimens. [Here's a look at what we learned about each microscope's pros and cons while using them to look at tardigrades.]

If you're interested in doing the same, you can buy live tardigrades from Carolina Biological Supply Co.

BUY tardigrades >>>

Overall, we found that the digital microscopes are completely unsuitable for looking at things as small as tardigrades, which grow to be no longer than a millimeter, or about the thickness of a credit card. The nondigital optical microscopes, however, produced some amazing tardigrade images.

Let's have a look under the lens:

Traditional microscopes

Omano Monocular Compound Microscope

In this image snapped through the lens of the Omano, you can see a couple of the tardigrade's legs and it's "face," with its tubular mouth. If you could dive even closer to its mouth, you'd see a telescoping structure and a whirl of teeth for grabbing food. Some tardigrade species feast on leafy foods like algae, while others are carnivores and devour meaty snacks that are smaller than themselves — such as rotifers.

My First Lab Duo Scope

What a cutie! But what's up with those teensy bubble-like structures inside its gut? Turns out, they aren't eggs (though we do have a photo of a pregnant tardigrade.) They're called coelomocytes, according to Paul Bartels, a professor of biology at Warren Wilson College in Asheville, North Carolina. "These are large cells that move freely in the body cavity," he told Live Science. "They are used for energy storage — those with more seem to survive cryptobiosis [a dormant-like state during harsh conditions] better than those with few."

AmScope Kids

This seemingly benign blob under the AmScope lens could likely survive being completed toasted and dried out and even being hit by a nuclear disaster and even worse. Research out in 2017 revealed one secret to their superpowers: They have a special protein that forms glass-like structures to preserve dessicated cells.

Digital microscopes

Because of the way these digital microscopes are constructed, with the lights and the plastic cap on the front of the scope, you are extremely limited in how close you can get to items being viewed. That means the tardigrades are probably always too far away from the lens to allow the necessary magnification. In our testing, we never saw any tardigrades with any of the digital microscopes, even when we knew for sure they were there. 

Plugable USB 2.0 Digital Microscope with Flexible Arm

Not much to see here. The tardigrade never came into view with this microscope. Here's a fun (and gross) fact about this creature we can't see through the Plugable 2.0: It takes huge poops. Back in May, a Harvard graduate and biologist posted a video on Twitter showing a tardigrade with a dark mass about a third the lenght of its body inside its belly ... just before it expels the giant poop. 

Celestron 5 MP Handheld Digital Microscope Pro

Our tries at seeing the tardigrade through the Celestron lens were also in vain.

Dino-Lite USB Handheld Digital Microscope

Though the Dino-Lite and the other digital microscopes failed to reveal our favorite mini beast, the microscopes are still useful. Check out what we learned from working with all of the microscopes on our Best Microscopes for Kids page.

Original article on Live Science.

Tardigrades are probably the most paradoxical animals on the planet. On the one hand, these microscopic organisms are impossibly cute, seeming like tiny blimps that bumble around harmlessly on their stubby legs. But they also enjoy a legendary reputation as the toughest, most indestructible creatures on Earth.

Just 0.04 inches (1 millimeter) long (or less), their little bodies contain biological superpowers that help them withstand conditions that would spell certain death for other organisms. Taking their toughness into account, how long can these creatures live?

That depends on where they're found. Tardigrades occur almost everywhere on the planet, but most are happiest frolicking about in moist habitats, such as the moss that adorns river stones. When tardigrades have enough food and water to support their bodily functions, they live out the natural course of their lives, rarely lasting for longer than 2.5 years, according to Animal Diversity Web, a database run by the University of Michigan. [How Did Life Arise on Earth?] 

And yet, tardigrades can survive for much longer if they go into a state called cryptobiosis, which is triggered when environmental conditions become unbearable.

"Tardigrades are fascinating little beasties," said Sandra McInnes, a tardigrade researcher with the British Antarctic Survey, who has been studying species that occur in the frozen snowscapes of Antarctica since 1980. "Tardigrades have this ability to cope with extreme environments by shutting down their metabolism. This ability to cope with drying out or freezing is what gives them their durability in the Antarctic."

Cryptobiosis puts tardigrades into a "tun" state, slowing their metabolism to a halt, reducing their need for oxygen and ridding their cells of water almost completely, according to the Encyclopedia Britannica. In this shrunken state, tardigrades mimic death so closely that they're able to survive in places devoid of water, at temperatures as low as minus 328 degrees Fahrenheit and as high as 304 degrees F (minus 200 Celsius and 151 degrees C). When these mummy-like tardigrades are exposed to water again, they simply reanimate, returning to normal life in a matter of hours.

"So long as the tardigrade can get into the tun, it will cope with anything that you throw at it," McInnes told Live Science.

McInnes once defrosted a moss sample from a former experiment and found it contained live tardigrades. She deduced that the organisms had survived, frozen, for at least eight years. In 2016, a paper published in the journal Cryobiology made waves when it showed that a handful of tardigrades, frozen in another Antarctic moss sample back in 1983, had survived in this frigid state for 30 years until they were revived in 2014. It's thought that the tardigrade's talent for self-preservation comes down, in part, to its production of unique proteins that can lock fragile cell components into position. That protects the membranes, proteins and DNA from being shattered, pierced and torn when cells become desiccated, according to a 2017 study in the journal Molecular Cell.

But the range of risky scenarios that tardigrades can survive has left scientists puzzled by just how these little beasties pull it off. "We are literally just scratching the surface of the biochemistry, the molecular pathways by which these animals cope with these environments," McInnes said. For instance, along with being frozen, boiled and dried, it's known that tardigrades can withstand pressures of up to 87,000 pounds per square inch (600 megapascals) — six times what you'd experience at the bottom of the sea. Just half this pressure would kill most other organisms on Earth. [What's the Oldest Living Organism?]

Many researchers have gone to extreme lengths to test tardigrade resilience, by blasting them (in their tun state) into space. In many of these studies, the space-traveling tardigrades were exposed to direct solar radiation and gamma-rays. But when they were popped into a water-filled petri dish back on Earth, they "basically walked away and said, 'OK, where's dinner?'" McInnes said. Tardigrades are seemingly able to resist radiation and even repair their DNA, which may explain why they're so resilient to radiation's extreme effects, a 2013 PLOS ONE study reported.

"If they've got this ability to last over time, how long do they live? Well, how long is a piece of string?" McInnes said. But she cautioned against the prevailing belief that tardigrades are invincible: "They can't live forever," she said. The widely publicized notion that tardigrades can survive in a tun state for 100 years or more is an overstatement, for instance. And high-stress living does take its toll on their physiology. Only some tardigrades survive the torments of experimental freezing, boiling and radiation that we humans subject them to.

But there is another way to appreciate their resilience: on a species level. Not only have tardigrades existed since the Cambrian period 541 million years ago, but they may well go on to outlive us — and probably all other life on Earth, according to a 2017 paper published in the journal Scientific Reports. It found that if a cataclysmic event like an asteroid impact were to befall Earth and destroy life, a group of tardigrades inhabiting the ocean's Mariana Trench would endure.

As well as being impossibly cute, it would therefore seem that tardigrades are our surest hope for maintaining life on this planet.

Original article on Live Science.

Pushing the tiny-house movement to bizarre new limits, French scientists have constructed the "world's smallest house" on the tip of an optical fiber.

With each wall spanning about 0.0006 inches in length (15 micrometers, or 15 millionths of a meter), the humble chalet is too small to accommodate a dust mite, an amoeba or a sperm cell. It's about 10,000 times too small to host a tardigrade; it's even too small to hold a piece of tardigrade poop. [8 Reasons Why We Love Tardigrades]

So, why build a house so small that even a tardigrade can't make use of it? Mainly just to prove it can be done. According to a new paper published in the May issue of the Journal of Vacuum Science and Technology, this project was a test of a new nanoconstruction platform known as the MicroRobotex (or μRobotex) station — a high-tech rig built at the Femto-ST Institute in Besançon, France, with the sole purpose of affixing microscopic, 3D components onto ridiculously small surfaces.

"We decided to build the microhouse on the fiber to show that we are able to realize these microsystem assemblies on top of an optical fiber with high accuracy," study author Jean-Yves Rauch, a researcher at the Femto-ST Institute, said in a statement.

The fabrication station combines a focused ion beam (which uses charged particles to cut and bend micron-thin sheets of construction materials) with a gas injection system to stick those pieces together, and a set of tiny robot arms capable of maneuvering components with exceptional accuracy. Taken together, the rig allows researchers to build three-dimensional structures on the tips of optical fibers — a construction area of just 0.0001 square inches (300 micrometers by 300 micrometers).

Using this high-tech construction kit, the team members built their teeny, tiny house the same way you might build a cube out of construction paper (only with much, much more expensive scissors). Each surface of the house was etched onto a single sheet of micron-thin silica crystal; cut free with an ion beam; and then folded into place, origami-style, with some help from the team's tiny robot helpers.

The finished chalet has four walls, seven windows and an intricately tiled roof. It even has a little chimney on top, because "it snows in winter and it is cold"in Besançon, the researchers wrote in the study.

While the teeny house may seem like a frivolous application of such advanced technology, this piece of microscopic real estate is merely a proof of concept, the researchers wrote. The team has already moved on to constructing new microstructures that could enable optical fibers to detect radiation levels in jet engines or viral molecules in blood vessels. It may not help put a roof over any tardigrade heads — but honestly, they'll probably be fine without it.

Originally published on Live Science.

Here are some things that are true about tardigrades: They're tiny, measuring between 0.05 millimeters to 1.2 mm (0.002 to 0.05 inches) long, right on the edge of visible. They're not one species, but a whole phylum of animals. (A phylum is a broad category; There are just 32 phyla in the animal kingdom.) They're incredibly common in wet soil. And they're among the hardiest creatures on Earth, able to survive dehydration, blasts of radiation, and intense swings in temperature.

Here's something else that's apparently true about them: They take great big poops.

Tessa Montague, a recent PhD graduate of Harvard's Department of Molecular and Cellular Biology, posted a video on Twitter of a tardigrade, well, taking a huge poo. The little animal has a large dark mass in its digestive tract, about a third of its total length. And in the remarkably clear video Montague posted, the poop passes out of the tardigrade's rectum, then it kicks all eight of its little legs to squirm away from it. Its two rear legs scrabble at the poo as it moves.

Live Science reached out by email with a few questions for Montague about the video and tardigrade poop, and her answers are printed below, lightly edited for clarity.

Live Science: About how often do tardigrades poop?

Tessa Montague: I have no idea. The scientist who provided me with the tardigrades, Bob Goldstein (a prof at UNC Chapel Hill), had not yet borne witness to tardigrade defecation when I showed him this video, so that would suggest this kind of pooping doesn’t happen very often.

LS: Are the poops always this big compared to their bodies?

Montague: Yes (n=2) [this means she's only seen two examples]. There is one other tardigrade pooping video online, and that poop was also very large. Interestingly, that tardigrade seemed to struggle to relieve itself more than mine did. There might be a technical explanation: My tardigrade was lightly pressed between two cover slips to keep it from moving out of the frame of the microscope, so it’s possible that by doing this, I added a little extra oomph to the poop release. Hopefully the tardigrade felt as relieved as I did watching it.

LS: Do we know how much they weigh?

Montague: No, afraid not. The tardigrade is about 0.2 mm (0.008 inches) long, so perhaps you could calculate an approximate biomass for the poop.

LS: What are the poops made up of?

Montague: Tardigrades eat lichens, algae etc. so the poop was probably partially digested lichen. I captured this footage using a phase contrast setting on the microscope, so it’s in black and white. In full technicolor, the poop is bright green!

LS: Is there anything else you think readers should know about tardigrades and their poops?

Montague: Apparently some tardigrades only poop when they molt. Not this guy. This species molts when it lays eggs.

Originally published on Live Science.

They're adorable and indestructible

It doesn't need to be said, but we'll say it anyway: Tardigrades are amazing.

Their tiny, endearingly tubby bodies — about half a millimeter long — can dry out for years at a stretch and then revive with no damage. They can endure extreme heat and cold that would kill most other forms of life, and they can even withstand radiation in space.

Whether you know them as water bears or moss piglets, they’re microscopic bundles of awesomeness, and here are 8 reasons why.

They're basically just heads

You may be familiar with the comics series and T.V. show "The Walking Dead," and you might know the music of "The Talking Heads." But if tardigrades were to form a band, they might call themselves "The Walking Heads."

All tardigrades have plump, compact bodies, with four leg-bearing segments — each sporting a pair of clawed limbs — and a stubby head tipped by a toothy mouth ring. But the relationship of their body segments to the bodies of other arthropods has proven tricky to nail down, and the explanation might be that tardigrades are actually just heads with legs, researchers noted in a study published in 2016 in the journal Cell Biology.

At some point in their evolutionary past, tardigrades lost several genes linked to the development of body segments, and along with that they also lost the body parts that correspond to the thorax and abdomen in other arthropods, the study authors reported. Tardigrades' present "segmented" body plan closely resembles the head segments found in arthropods, showing that when it comes to evolution, there's more than one way to get a head.

They lay eggs topped with grasping "spaghetti"

Tardigrades can live just about any place on Earth where there's water, and a new species was recently discovered in a parking lot in Japan.

There are more than 1,000 known tardigrade species, and Macrobiotus shonaicus became the 168th species from Japan when it was described in a study published Feb. 28 in the journal PLOS ONE. Tardigrades are often found living in moss and lichens, and the new species turned up in a moss sample that the study's lead author had collected from a parking lot near his apartment, which was "quite surprising," he told Live Science in an email.

But the oddest thing about this tardigrade was not its urban location, but its eggs, which were topped with wiggly, spaghetti-like tendrils. These noodly appendages may help to attach the eggs to surfaces after the tardigrade leaves them, the study authors reported.

They can withstand intense heat and freezing cold

Hardy tardigrades can survive punishing conditions that would be lethal to most living things, weathering temperatures up to 300 degrees Fahrenheit (149 degrees Celsius) and as low as minus 328 degrees Fahrenheit (minus 200 degrees Celsius).

They do this by expelling all the water from their bodies, retracting their stubby limbs, and curling up into dried-out balls, a type of suspended animation known as a "tun." When the danger has passed, they rehydrate and return to normal, with seemingly no ill effects.

Recently, scientists discovered that a certain type of protein that is unique to tardigrades may be the secret to their recovery prowess. Tardigrade species that had a constant supply of this protein were more successful at recovering from a tun state than their cousins that did not always produce the protein, according to a study published in March 2017 in the journal Molecular Cell.

They have no childhood, hatching from their eggs fully formed

Researchers have long been fascinated by tardigrades, which have been around for at least 500 million years, and in 1938 scientists learned that minuscule water bears hatch from their eggs in their adult forms.

Many arthropod relatives of tardigrades have a distinct larval stage as juveniles, in which their bodies look dramatically different from those of adults — picture the chubby grubs that grow up to be termites, or the caterpillars that metamorphose into moths or butterflies.

Hatchling tardigrades, on the other hand, look exactly like adult tardigrades, if a little smaller. Molting occurs several times during tardigrades' lifetime, during which they shed their skins to accommodate their growing bodies, but they maintain the same body plan throughout their lives, according to a study published in May 2015 in the journal Polar Biology.

They have a built-in "space suit"

Not only can tardigrades survive exposure to extreme temperatures, they can also withstand boiling liquids and pressures up to six times that at the ocean's deepest regions. But tardigrades' survival superpowers extend even further, beyond conditions on Earth to encompass the hazards of space travel.

Tardigrades can recover after facing unfiltered solar radiation and space's vacuum, adding them to an "exclusive and short list of organisms" capable of doing so, researchers reported in September 2008 in the journal Current Biology.

Dried-out adult tardigrades and eggs in two species — Richtersius coronifer and Milnesium tardigradum — were exposed to space vacuum and radiation over 10 days at low-Earth orbit, about 846,000 to 922,000 feet (258,000 to 281,000 meters) above sea level. The specimens were then later resuscitated and examined.

Both species survived "very well" after exposure to the vacuum of space, though survival among those exposed to radiation was "significantly reduced," the study authors reported.

They can be frozen for decades and still reproduce when they wake up

Two Acutuncus antarcticus tardigrades that spent over 30 years in a researcher's freezer were successfully resuscitated, and one of them almost immediately started getting busy.

The tardigrades were retrieved from a piece of moss that had been stored at minus 4 degrees Fahrenheit (minus 20 degrees Celsius) since 1983, and the animals were in a suspended state known as "cryptobiosis," showing no signs of their normal metabolic processes.

But just one day after rehydration, one of the tardigrades was stretching its legs, and by the time 22 days had passed, researchers saw eggs inside its body. It eventually laid 19 eggs, producing 14 live hatchlings.

They inspire new kinds of glass

A new type of glass that could improve the efficiency of solar cells and LED lights owes its inspiration to tiny tardigrades.

When these microscopic creatures expel all the water from their bodies to enter their suspended "tun" state, special proteins that are only found in tardigrades turn the fluid inside their cells into a glasslike substance, protecting biological structures until the tardigrade can be rehydrated and revived.

Researchers were intrigued by this ability, which led them in 2015 to develop a glass material with a molecular structure that was highly organized, more akin to crystals than glass. These "oriented" molecules could make glass more efficient at capturing and directing light, which could improve the performance of devices such as optical fibers, LEDs and solar cells, the scientists said in a statement.

They may outlive humanity, this planet, and possibly even the sun

People joke about "our insect overlords," but when the curtain comes down on our solar system, it may well be tardigrades that have the last laugh.

A team of scientists considered a series of doomsday scenarios that would be catastrophic for humanity, including nearby supernovas, the expansion of our own sun to a red giant star, and a massive asteroid colliding with Earth.

In every scenario, tardigrades were just fine, confirming that when it comes to life on Earth, they are as close to indestructible as it gets, the researchers said in a statement. We can therefore all rest assured that even if a sequence of devastating events — or one enormous planet-killing disaster — manages to wipe out most species alive today, the tardigrades will still somehow manage to come out on top, ensuring that "life as a whole will go on," the scientists concluded.

When troops are injured on the battlefield, time is of the essence: How long it takes service members to receive medical care is often the single most important factor in determining whether they live or die.

Now, scientists are looking at new ways to buy some extra time for battlefield injuries, but not by getting medical care to troops faster. Instead, the scientists want to essentially slow down time.

And they're taking a cue from tiny creatures called tardigrades.

A new program from the Defense Advanced Research Projects Agency (DARPA) — the U.S. agency tasked with developing new technologies for the military — aims to develop treatments that literally slow down the body's biochemical reactions, tipping the body into a slowed or suspended state until medical care is available. In other words, the program, called Biostasis, aims to "slow life to save life," according to a DARPA statement.

Such a treatment sounds like science fiction, but there are organisms on Earth that employ similar strategies to stay alive in seemingly deadly environments. For example, tardigrades, the microscopic creatures often known as "water bears," can survive freezing, dehydration and extreme radiation. They do so by entering a state called "cryptobiosis," in which all their metabolic processes appear to have stopped, but the organisms are still alive.

"Nature is a source of inspiration" for the project, Tristan McClure-Begley, the program manager of Biostasis, said in the statement. [Biomimicry: 7 Clever Technologies Inspired by Nature]

"At the molecular level, life is a set of continuous biochemical reactions," McClure-Begley said. Often, these reactions occur only with the help of proteins or "molecular machines" called catalysts, which speed up the rate of chemical reactions.

"Our goal with Biostasis is to control those molecular machines and get them to all slow their roll at about the same rate, so that we can slow down the entire system gracefully, and avoid adverse consequences when the intervention is reversed or wears off," McClure-Begley said.

But perfectly preserving bodies on the battlefield as they wait for medical attention is still a long way off.

First, the scientists plan to examine various ways to slow down biochemical processes in cells and tissues, and eventually scale up to the level of a complete organism, the statement said. A treatment will be considered successful if it slows down all measurable biological functions within a system and the treatment doesn't damage cellular processes when the system returns to "normal" speed.

Technologies developed through the Biostasis program might also be used to extend the shelf life of blood products or biological reagents and drugs, the statement said.

A webinar about the Biostasis program will be held on March 20 at 12:30 p.m. EDT.

Original article on Live Science.

A newfound species of tardigrade, or "water bear," with tendril-festooned eggs has been discovered in the parking lot of an apartment building in Japan.

The newfound tardigrade, Macrobiotus shonaicus, is the 168th species of this sturdy micro-animal ever discovered in Japan. Tardigrades are famous for their toughness: They can survive in extreme cold (down to minus 328 degrees Fahrenheit, or minus 200 Celsius), extreme heat (more than 300 degrees F, or 149 degrees C), and even the unrelenting radiation and vacuum of space, as one 2008 study reported.

They're bizarre and adorable at the same time, with eight legs on a rotund little body (they're usually far less than a millimeter in length) and circular mouths that make them look perpetually surprised.

Kazuharu Arakawa, a researcher who studies the molecular biology of tardigrades at Japan's Keio University, discovered the newfound species in a small sample of moss. He'd scraped the moss from the parking lot of his apartment in Tsuruoka City along the Sea of Japan. [Extreme Life on Earth: 8 Bizarre Creatures]

"Most of [the] tardigrade species were described from mosses and lichens — thus any cushion of moss seems to be interesting for people working on tardigrades," Arakawa told Live Science in an email. But, he said, "it was quite surprising to find a new species around my apartment!"

Spaghetti eggs

Arakawa routinely samples moss he finds around town, he said, but the portion from his parking lot turned out to be special. The tardigrades he found there could survive and reproduce in a laboratory environment, which is very rare for these creatures, he said.

He sequenced the tiny animal's genome and only then realized that it matched no previously found tardigrade sequence. Arakawa looped in tardigrade expert Łukasz Michalczyk of Jagiellonian University in Poland, and the researchers determined that they had a newfound species on their hands. 

The species ranges in length from 318 micrometers to 743 micrometers. It has the typical plump-caterpillar look of a tardigrade, and its O-shaped mouth is ringed by three rows of teeth. It can live on algae, which is odd because other species in the Macrobiotus genus are carnivores that eat even tinier animals called rotifers, Arakawa said. [In Photos: The World's Freakiest Looking Animals]

Perhaps the weirdest aspect of M. shonaicus, though, is its eggs. The spherical eggs are studded with miniscule, chalice-shaped protrusions, each of which is topped with a ring of delicate, noodle-like filaments. These features might help the egg attach to the surface where it is laid, Arakawa said. 

Tardigrade family tree

The newfound species is part of a set of tardigrade species, known as the hufelandi group, that all have these cup-like egg decorations, Arakawa and his team reported today (Feb. 28) in the open-access journal PLOS One. Macrobiotus hufelandi was the first tardigrade species ever discovered, way back in 1834. That species was found in Italy and Germany originally, but it and its close relatives have now been found all over the globe, Arakawa said. 

"This is the first report of a new species in this complex from East Asia," he said. More tardigrade-hunting is necessary to find out how tardigrades diversified and adapted over time, he said.

Also exciting is that M. shonaicus can thrive in the lab, Arakawa said.

"It is an ideal model to study the sexual-reproduction machinery and behaviors of tardigrades," he said. "We are actually already submitting another paper describing their mating behaviors."  

Original article on Live Science.

It started as a speck of a speck, a bundle of nerves and immature tissues curled up inside an egg, bunched up against its siblings. The small clutch of embryonic water bears was immobile, silent, unseeing and possibly unfeeling. Locked away inside their mother's ovaries, they waited to be born.

One of nearly 1,000 species of hardy tardigrades, the Hypsibius dijardini embryo pictured above may have been the product of a sexless act of reproduction, its mother squirting her genetic material directly into eggs without bothering with any of the handful of males of her species for fertilization, according to the Encyclopedia of Life. That reproductive ability (called parthenogenesis), a genetic heritage largely unchanged through the generations, was her birthright and one she would likely have passed down to her children.

Tardigrades are among the hardiest animals on planet Earth, resistant to heat and cold, radiation and extreme dehydration. This H. dijardini embryo would have eventually emerged from its egg fully formed, and as ready to take on those horrors as her mother had been. Tardigrades, as researchers studying them way back in 1938 for a paper in American Midland Naturalist discovered, have no childhood. They pierce through their eggs small, but fully formed.

The embryo captured by photographer Vladimir Gross is 50 hours old, nearing readiness to emerge. All of her limbs, mouth parts and most of her organs developed over the course of those hours, before and after her mother squeezed her out into the world. (Gross snagged runner-up in the Royal Society Publishing Photography Competition's Microimaging category.)

When the egg-enclosed baby was ready, the 1938 researchers discovered, she would have driven her mouthparts into the wall of her egg, carved a small hole, and wriggled through it into her new life. Her organs, streamlined for digestion and reproduction, would already be churning. She wouldn't swim through her wet world, but would instead get around on her eight stubby, clawed legs.

If she were in the wild, she would have gotten to work munching on the wet mosses and small plants where she would have made her home. And with all the food she would take in, she would grow. Over the course of her lifetime, she could expect to cast off her outer skin several times to make room for her growing body, according to a study published in 2015 in the journal Polar Biology.

According to The Encyclopedia of Life, she would have been ready to give birth to her first batch of eggs within two weeks of her own birth — between one and 30 tardigrade embryos, depending on how much food she'd had available. Some species of tardigrade lay eggs inside their cast-off skins. Some wait for males to fertilize them, but not H. dijardini. Except in unusual circumstances, which scientists still do not fully understand, she would create eggs with near-exact copies of her genetic code, just like her mother had with her.

She could expect to birth several more clutches of eggs in her life, which would last another 70 or so days — unless, of course, she were frozen or dehydrated, in which case she might live on in a dormant state for months, years, decades or longer, until the world was ready for her again. Then she would wake up, and get right back to the business of being a water bear.

Originally published on Live Science.

Science speaks

Photos are said to be worth "a thousand words." And that's what the Royal Society looks for when judging images for their Publishing Photography Competition, which "celebrates the power of photography to communicate science and the role great images play in making science accessible to a wide audience." The judges received more than 1,100 entries for the 2017 competition, with winners' shots ranging from a close-up of a tardigrade embryo (showing the water bear baby's every nook and cranny), to an aerial of Antarctic "ice cubes," to a pensive polar bear. Here's a look at the award-winning photos.

Icy sugar cubes

Photographer Peter Convey took the overall winner as well as the winner in the Earth Science and Climatology category with this image called "Icy Sugar Cubes."

Using a Pentax ME Super camera and 70-300 mm zoom, Convey flew over the southern Antarctic Peninsula capturing unusual bi-directional crevassing on an ice sheet. A Twin Otter airplane displays the scale of the fissures.

Bow first

An image of the Russian research vessel, the Akademik Tryoshnikov, sitting at the snout of the Mertz Glacier in Eastern Antarctica won the photographer Giuseppe Suaria runner-up in the Earth Science and Climatology category.

Moments after the photo was snapped, a remotely operated underwater vehicle named ROPOS was deployed to examine the melting ice sheet.

Olive oil drop family

Snagging the winning position in the Micro-Imaging category, this image of tiny olive oil droplets was snapped with a Nikon D300 camera and Phlox backlight at 10,000 lux.

Photographer Hervé Elettro found inspiration from the Nephilia Madagascariensis spider which uses micro-glue droplets to trap its prey.

Water bear embryo

Photographer Vladimir Gross' image of a 50-hour-old embryo of a Hypsibius dijardini, a species of tardigrade, snagged runner-up in the Micro-Imaging category of the 2017 Royal Society Publishing Photography Competition.

Waiting in the shallows

King penguins busy themselves with preening at the water's edge on Marion Island, in the Indian Ocean and part of South Africa. In the bay, a group of killer whales surface, startling a group of penguins in the water. And, a Lesser Sheathbill watches the entire scene perched on a rock. This beautiful and busy photo garnered photographer Nico de Bruyn winner in the Ecology and Environmental Science category.

Invincible ants

While the Nepenthes bicalcarata, a species of carnivorous pitcher plant, presents certain death to many insects, the Camponotus schmitzii ants are impervious to its traps. As seen is this image, which won photographer Thomas Endelin runner-up in the Ecology and Environmental Science category, the specialized ants live in the vines of the plant and climb in and out of the pitcher with no problem.

Respiro

Photographer Antonia Doncila, of Edinburgh University, snapped this image while crossing the Fram Strait, between Greenland and Svalbard in the Arctic Ocean. A polar bear gazes into the water from a portion of fast ice. Many polar bears are not so lucky and die in the open ocean while swimming for sea-ice. The image, taken with a Canon EOS 5D Mark II + Tamron telephoto lens, was the winner in the Behavior category.

Breeding

Taking runner-up in the Behavior category of the 2017 Royal Society Publishing Photography competition, this unique image of two Arctic terns "communicating" on their cleverly chosen nest: an abandoned shovel. Photographer David Costantini of the Muséum National d'Histoire Naturelle in Paris, France, captured the image in Svalbard.

Lunar spotlight

A rare optical phenomenon created by ice crystals in the atmosphere brought photographer Daniel Michalik, of the School of Biosciences, University of Kent, the winning image in the Astronomy category. The image was captured with a single long exposure. The illusion is created more often in the geographic South Pole than other non-polar regions.

The rainy season

In the Brazilian semi-arid desert of Caatinga, the first summer rains birth a spectacular green world that's lush with flora and alive with fauna. The Phyllomedusa nordestina frog dons a new bright green garment with which to woo potential mates.

The inspiring image garnered photographer Carlos Jared of Instituto Butantan, Cell Biology Laboratory, Sao Paulo, Brazil, honorable mention in the Ecology and Environmental Science category of the contest.

Acari trapped in spiderweb

With this image of an Acari spider mite hanging from a thin string of a spider's web in the Chilean temperate forests, photographer Bernardo Segura, of the University of Chile, snagged honorable mention in the Micro-Imaging category of the contest. The web, spun by Austrochilus spiders, have some threads with stunning bluish tones.

Diamond ring through thin clouds

IPhotographer Wei-Feng Xue got the rare chance to observe a total solar eclipse along the path of totality in northern Georgia on Aug. 21, 2017. His gorgeous image of the Great American Eclipse, with the sun's corona showing up like a diamond ring, snagged runner-up in the Astronomy category. To capture the shot, Xue used a Canon EOS6D digital SLR camera with an EF 70-200mm + 2x extender.

Pele's fire

Using a 55-300mm Tele lens, photographer Sabrine Koehler of the University of Hawai'i at Manoa won honorable mention in the Earth Science and Climatology category of the 2017 Royal Society Publishing Photography Competition and collected a stunning image of the power of the 61g lava flow at the current Pu'u O'o eruption site of the Kilauea volcano. The term "61g" refers to the seventh flow (indicated by letters of the alphabet) in the sequence of events that make up the so-called 61st episode of the current eruption from the East Rift Zone of Kilauea, according to the U.S. Geological Survey.

Toss the scorpion

In Tadoba, India, photographer Susmita Datta captured an image of a rascally Indian roller bird playing with its morning snack, a scorpion. The image, taken during a morning safari on the Tadoba Andhari Tiger Reserve using a Canon 60D with a Sigma 150-500 lens, brought an honorable mention in the Behavior category to the photographer.

Within Reach

Over ESO's Paranal Observatory, the skies echo oil on water with the many colors blending into an shimmering skyscape.

The image, featuring our own Milky Way arching across the Chilean night sky with the Very Large Telescope off in the far distance, won photographer Petr Horálek an honorable mention in the Astronomy category of the 2017 Royal Society Publishing Photography Competition.

People are gearing up to spread life from our solar system out into the cosmos. But the first life-forms to make that journey won't be human beings, or even critters most folks would recognize. Instead, scientists plan to send tiny, chubby, pinch-faced tardigrades on the first living journey out past the Oort cloud (the ring of icy debris around our solar system) and into interstellar space.

Why tardigrades? Well, if you've heard anything about these eight-legged, dirt-dwelling "water bears" before, it was probably because they're ridiculously resilient against ravages of the universe — ravages both foreign and domestic to our planet. Boiling doesn't kill them. Neither does extreme pressure nor extreme cold. A study published online July 14 in the journal Scientific Reports suggests that even Earth-pummeling asteroids, nearby supernova blasts and powerful interstellar bursts of gamma radiation would fail to wipe the buggers out.

That hardiness, along with their small size — reaching only about a millimeter (0.04 inches) long — makes tardigrades ideal candidates to make a first cruise outside the solar system. These moss piglets, as they're sometimes adoringly called, join C. elegans, a kind of mulch-dwelling nematode, as finalists to surf laser beams at relativistic speeds (or those approaching the speed of light) astride wafer-size spacecraft toward the far edge of the solar system, Space.com reports. The outer-space trip on laser-fueled wafers was borne out of NASA's Starlight program, whose aim is to use photons to push tiny objects at extreme fractions of the speed of light toward neighboring stars. [7 Huge Misconceptions About Aliens]

Tardigrades have a special power that makes them particularly useful for extrasolar experimentation: They're super-dehydrators and super-freezers. Under extreme dehydration and cold, they shrivel up into little balls to wait out the trauma. When conditions improve, they rehydrate (or melt their internal liquids) and carry on like nothing's changed. That means, the project's authors wrote on their website, that interstellar tardigrades could be periodically knocked out, stored and reawakened under different conditions to observe their behavior.

C. elegans, meanwhile, make good candidates for the trip because scientists already have a huge wealth of data about their genetics and behavior. At just under 1,000 cells in their bodies, they are fairly simple to study; and despite their small size, they can observe their environment, learn from it and adjust their actions as a result. Also, like tardigrades, they can be frozen and revived. [Extreme Life on Earth: 8 Bizarre Creatures]

It also helps, of course, that both species are on the far low end of the animal size scale. C. elegans are microscopic, and tardigrades are just on this side of visible to the naked eye. That's plenty small enough to pack some onto miniscule spaceships for Earthly life's first journey into the stars.

Though plans are still fluid, the Russian philanthropist and funder of the Breakthrough Starshot program Yuri Milner has said that the first interstellar trip could happen by 20 to 25 years from now, with one proposed target being our closest star system, Alpha Centauri.

Originally published on Live Science.

Tardigrades, also known as water bears, are less than a fraction of an inch in length, yet they are believed to be Earth's toughest, hardiest animals. They are virtually indestructible. Tardigrades have the ability to withstand complete dehydration. Once desiccated, they have been frozen in blocks of ice, exposed to radiation, and sent into the vacuum of space, and yet they still usually spring back to life when water becomes available again.

New genetic research, published in the journal PLOS Biology, reveals how tardigrades achieve such resurrections after drying to a crisp. The authors now even believe that alien life forms could possess this remarkable ability.

"If life exists on other planets, and it is water-based, then those organisms that live out of water will evolve to resist extreme events, including the threat of drying out," said co-author Mark Blaxter of the University of Edinburgh's Institute of Evolutionary Biology.

He added that the ability to undergo anhydrobiosis — the desiccated, dormant state — "has evolved multiple times on Earth, so I am sure it will have evolved on other living planets."

Blaxter and his colleagues took a clever approach to unravel the scientific secrets behind anhydrobiosis in tardigrades.

The scientists re-sequenced and reassembled the genome of Hypsibius dujardini, a tardigrade that can only undergo desiccation after extensive pre-exposure to drying conditions. They then compared the tiny animal's DNA with that of Ramazzottius varieornatus, a related species with tolerance to rapid desiccation.

The researchers then looked at a particular set of genes, the so-called HOX genes, which establish the nose-to-tail pattern in embryos. There are usually about ten different HOX genes in animals, but tardigrades are missing five. Nematodes (roundworms) lack these same five genes.

RELATED: Microscopic Tardigrade 'Water Bears' Will Be the Last Survivors on Earth

"This could be because they share a common ancestor with tardigrades, and the loss happened in this ancestor," Blaxter said. "Alternatively, it could be that the loss is associated with both groups becoming miniaturized, and these 'middle' HOX genes are the ones that are the easiest to lose."

He added that the shared genetic loss could also simply be due to independent evolution. Because of these remaining questions, scientists continue to debate whether or not tardigrades are more closely related to nematodes or to arthropods — insects, spiders, and crustaceans.

By asking which genes were turned on during tardigrade anhydrobiosis, the scientists could identify sets of proteins, which appear to replace the water that tardigrade cells lose, thus helping to preserve the microscopic structures until water is available again.

Arakawa explained that all cells contain around 60–80 percent water when they are active, including human cells.

The key proteins that they identified are highly soluble. They dissolve in water that, due to surface tension, clings to and surrounds intracellular molecules within tardigrades. Like a microscopic protective coating, they prevent the cells from denaturing when the animal otherwise desiccates.  

Arakawa added that tardigrades also possess additional genes that protect their DNA from damage. Because these small animals lack stress-sensing pathways, their cells do not usually die out when damaged. Instead, the identified proteins try to make repairs, and are often successful in doing so.

Due to these abilities, scientific consensus holds that tardigrades could be Earth's last survivors. Such resilience is unexpected in a tiny creature that seems to exist in the slow lane.

"Tardigrades are slow walkers, and are not really aggressive animals," Arakawa explained. "Therefore, they tend to lose competitions for food, or can become prey in a diversified ecosystem. But tardigrades fled to their own niche, where only tardigrades can survive, so paradoxically, tardigrades presumably acquired their extreme survival abilities due to their ecological incompetence."

RELATED: Tardigrade 'Water Bear' Dries to a Crisp and Then Comes Back to Life

Arakawa and his colleagues can envision a day when enzymes, vaccines, human organs, tissues, and cells could be preserved in a state of anhydrobiosis instead of by liquid-nitrogen-based freezing.

"Some people have suggested that tardigrades could somehow travel through space to seed other planets with Earth-derived life," Baxter said. "That obviously didn't happen on Earth, as only some tardigrades are able to do anhydrobiosis, and tardigrades are derived from other, more ancient forms."

While it is doubtful that tardigrades are somehow hurtling through space now, these amazing animals continue to captivate researchers. Blaxter and Arakawa, for example, have been studying them with awe and admiration for years.

Blaxter, one of the few tardigrade genomics experts in the world, reminisced that his scientific career was sewn when, as a child, he was gifted with an animal encyclopedia by his parents.

"I especially pored over the weird and wonderful animals that were so beyond what I had seen with my own eyes," he recalled.

When, many years later, one of his Ph.D. students suggested that he study tardigrades, a lightbulb went off.

"We haven't looked back," Blaxter said.

Originally published on Seeker.

The eight-legged micro-animal called a tardigrade could survive nearly all the way until the death of the sun, a new study suggests — long after humans are history.

The study, from Harvard and Oxford universities, detailed the threats to life on Earth over billions of years, finding that Earth-pummeling asteroids, nearby supernova blasts and gamma-ray bursts would be unlikely to completely sterilize Earth (taking out the little tardigrades in the process).

Tardigrades, which are usually less than a millimeter long (0.04 inches), are nearly indestructible, some of the most resilient forms of life on Earth. They can survive for up to 30 years without eating, and can be frozen, boiled, squished under intense pressure, and exposed to the vacuum and radiation of space without ill effect. The animal, which lives in water (and is also known as a "water bear," can survive for up to 60 years, according to a statement from the University of Oxford. [Earth's 'Alien' Creatures May Reveal Clues About Extraterrestrial Life]

"'A lot of previous work has focused on 'doomsday' scenarios on Earth — astrophysical events like supernovas that could wipe out the human race," David Sloan, a co-author on the new work and researcher at Oxford, said in the statement. "Our study instead considered the hardiest species — the tardigrade. As we are now entering a stage of astronomy where we have seen exoplanets and are hoping to soon perform spectroscopy [on those planets], looking for signatures of life, we should try to see just how fragile this hardiest life is."

"To our surprise, we found that although nearby supernovas or large asteroid impacts would be catastrophic for people, tardigrades could be unaffected," he added. "Therefore, it seems that life, once it gets going, is hard to wipe out entirely. Huge numbers of species, or even entire genera may become extinct, but life as a whole will go on."

The researchers detailed what would happen with each of those threats in a new paper, released today (July 14) in the journal Scientific Reports. 

How might Earth die?

Gamma-ray bursts, the most powerful explosions in the universe, are jets of radiation likely released when a star collapses into a black hole after emitting an ultra-powerful supernova blast. If one of those blasts occurred close enough to Earth, heading straight toward the planet, it could take out Earth's ozone layer, leaving Earthlings exposed to deadly radiation levels, the researchers wrote in the paper. But life that lived below ground or in large bodies of water would be shielded from harm and could survive, including the tardigrade.

To boil away Earth's oceans, the researchers wrote, a gamma-ray burst would have to occur less than 40 light-years away, if it were aimed right toward Earth.

An ordinary, less-powerful supernova would pose the same radiation danger, but it would have to be just 0.14 light-years from Earth to vaporize the oceans and sterilize the planet. One light-year, the distance that light travels in a year, is about 6 trillion miles (10 trillion kilometers).

A killer asteroid could cloud the sky with debris, killing life that relies on sunlight, or even lead to the loss of Earth's atmosphere. But life could live on deep in the ocean, or gather sustenance from volcanic vents, the researchers said. Less than 20 known asteroids and dwarf planets, including Vesta and Pluto, would provide enough of a kick to boil off Earth's oceans with their impacts — and none are headed toward Earth anytime soon.

Calculating the probability of each of those events, and factoring in the heightened temperatures and pressures in which tardigrades can survive, the researchers found an incredibly tiny probability that an ocean-boiling, life-ending event would occur within 10 billion years.

The sun will someday evolve into a red giant star and expand to be even larger in diameter than Earth's orbit. But before that point, the star would get hot and close enough to sterilize Earth for good, boiling away the world's oceans before consuming the planet or knocking it out of orbit — ending the tardigrades' reign at last. [Death of the Sun: How It Will Destroy Earth (Infographic)]

(And even then, the researchers said in the paper, there's a possibility that a planet's orbit will be disturbed enough by its star's expansion that it'll be knocked away early, wandering the galaxy as a rogue world. Scientists have discussed the possibility that creatures like tardigrades could survive on a free-floating planet for a time.)

Looking outward

Studies suggest that Mars once had better conditions for life, including a thicker atmosphere and lakes and streams. If life that developed on planets like Mars is anything like tardigrades, it would stick around despite the planet's current inhospitable conditions, the researchers said.

"It is difficult to eliminate all forms of life from a habitable planet," Avi Loeb, a study co-author and Harvard's chair of astronomy, said in the statement. "The history of Mars indicates that it once had an atmosphere that could have supported life, albeit under extreme conditions. Organisms with similar tolerances to radiation and temperature as tardigrades could survive long term below the surface in these conditions."

Similarly, the subsurface oceans on Saturn's moon Enceladus and Jupiter's moon Europa may feature volcanic vents that provide heat, similar to the locations where tardigrades can thrive deep under Earth's sea, he said.

"Tardigrades are as close to indestructible as it gets on Earth, but it is possible that there are other resilient species examples elsewhere in the universe," added Rafael Alves Batista, a co-author and researcher at Oxford. "If tardigrades are Earth's most resilient species, who knows what else is out there?"

Email Sarah Lewin at slewin@space.com or follow her @SarahExplains. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com. 

Microscopic, blobby-bodied tardigrades — also known as "water bears" — are famed for their ability to survive in extreme conditions, even appearing to come back from the dead.

But although tardigrades' hardiness has intrigued scientists for over 250 years, the mechanisms that enable these animals to recover after drying out for a decade or longer have remained a mystery.

Now, a new study reveals that special proteins coded into tardigrade DNA may be the secret to the creatures' resuscitation superpowers. [It's Alive! 'Water Bears' Revived After 30+ Frozen Years | Video]

Tardigrades measure between 0.002 and 0.05 inches (0.05 to 1.2 millimeters) in length, so they can't be seen with the naked eye. The wee beasties have endearing features: fat, segmented bodies; four pairs of chubby legs tipped with grasping claws that resemble those of a sloth; and rotund heads with a circular mouths.

Tardigrades live on damp moss and algae around the world. Researchers have found that tardigrades can withstand searing heat and freezing cold, up to 300 degrees Fahrenheit (149 degrees Celsius) and as low as minus 328 degrees Fahrenheit (minus 200 degrees Celsius). Tardigrades can even emerge unscathed after exposure to boiling, high pressure, and the radiation and vacuum of space.

The creatures survive by expelling the water from their bodies and entering a suspended state known as a "tun." During this state, they retract their limbs and shrink into tiny, desiccated balls, emerging only when life-threatening conditions have passed. But scientists have wondered how that was possible, particularly for tardigrades that spend a decade or more as dried-out tuns.

Tardigrade-specific proteins   

Previously, a sugar called trehalose was thought to be the key to tardigrade regeneration. This sugar is found in other types of animals and in plants, and is known to play a role in tolerance to dry conditions. However, prior studies of tardigrade biochemistry found little evidence that these animals have trehalose, suggesting that the sugar isn't the main driver for tardigrade recovery.

In the new study, researchers analyzed tardigrade genetic activity as the micro-animals dried out. First, the scientists identified which genes were highly active at the time, and then the researchers looked closely at what those genes do.

Results showed that certain genes were expressing a type of protein unique to tardigrades, which the scientists dubbed tardigrade-specific intrinsically disordered proteins, or TDPs. In some species of tardigrades, the genes that produce TDPs were active all the time, while in other species, these genes were activated only under certain conditions.

TDPs protected the tardigrades in much in the same way that trehalose protects other animals, by forming glass-like structures that help to preserve cells that are in a dehydrated state.

The tardigrade species that had a constant supply of TDPs was more successful at recovering from drying out than the species that weren't always producing TDPs, the researchers wrote.

"We think it can do this because it has so many of these proteins around already and doesn't need time to make them," study lead author Thomas C. Boothby, a Life Sciences Research Foundation Postdoctoral Fellow at the University of North Carolina, said in a statement.

The findings reveal that biological methods used to tolerate environmental stress and withstand desiccation are more diverse than suspected, the researchers said. Now that the role of TDPs in tardigrade resuscitation has been identified, other uses for the proteins could be found, such as protecting crops that are vulnerable to drought, or preserving perishable medications, Boothby said in a statement.

"Being able to stabilize sensitive pharmaceuticals in a dry state is very important to me personally," Boothby said. "I grew up in Africa, where lack of refrigeration in remote areas is a huge problem. These real-world applications are one of the things that led me to study tardigrades."

The findings were published online March 16 in the journal Molecular Cell.

Original article on Live Science.

After being locked in a deep freeze for more than 30 years, two microscopic creatures called tardigrades have been resuscitated, with one of the adults getting busy with reproduction "immediately" and "repeatedly," scientists reported.

Scientists were even able to revive a tardigrade egg after it spent the past three decades cooling its jets alongside the mature duo in a researcher's freezer.

Their findings shattered the previous preservation and revival record for tardigrades and their eggs, which had been eight years for frozen tardigrades and nine years for dried eggs stored at room temperature. [Video: Watch the Frozen Tardigrades Come Back to Life]

It's alive!

But after more than 30 years in this suspended state, they were brought back to life.

Scientists rehydrated them and video-recorded the results, observing that after just one day, a revived tardigrade was tentatively stretching a pair of its stubby legs. Six days after rehydration, the tardigrade was moving its body, as though it were trying to lift itself, the researchers noted. After 13 days had passed, the animal was eating algae, its first meal in decades, And after 22 days, eggs were visible inside the tardigrade's chubby body.

It eventually laid 19 eggs. A. antarcticus reproduce through parthenogenesis, which means that their embryos grow and develop without fertilization, and in this instance, a total of 14 hatchlings emerged.

The other tardigrade survived for just 20 days after rehydration, and died without reproducing. But the frozen egg hatched and produced a larva that went on to lay 15 eggs, of which seven hatched successfully.

Hard to kill

Tardigrades, which also go by the endearing names "water bears" and "moss piglets," measure about 0.02 inches (0.5 mm) long. They have eight limbs tipped with clawlike structures that propel their plump, segmented bodies through a variety of watery, algae-rich environments all over the world.

But they have a hidden superpower — surviving adverse conditions such as extreme heat or cold that would kill just about any other form of life. Tardigrades were even sent into low-Earth orbit in 2007, where they weathered exposure to space's vacuum, cosmic rays and solar ultraviolet radiation. Their secret lies in an ability to expel all the water in their cells and generate a protective coating, suspending them in a deathlike but still-living state that they can maintain until conditions improve.

Other tiny creatures are known for similar long-term preservation capabilities. The researchers described prior studies that revived refrigerated adult and larval nematodes, microscopic worms, after as long as 39 years.

But reviving a tardigrade after 30 years is unprecedented, and their ability to reproduce after a brief recovery period is a testament to their durability. It also raises questions about their preservation mechanisms, and how they and other organisms can survive a deep-freeze recover, and how they repair cellular and DNA damage when they're restored to life, Megumu Tsujimto, the lead researcher at National Institute of Polar Research, said in a statement.

Looks like the cold never bothered them anyway.

The study was published online Feb. 16 in the journal Cryobiology,

Follow Mindy Weisberger on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science.

A really weird, really tiny animal — the microscopic tardigrade — is the inspiration behind a new material that could improve the efficiency of things like LED lights and solar cells.

The material under investigation is glass, and tardigrades (sometimes known as "water bears" or "moss piglets") know a thing or two about glass. These water-dwelling critters, which look like tiny blimps with pudgy bodies and eight stubby legs, are capable of shedding almost all of the water in their cells when exposed to extreme conditions, such as heat, cold or even the vacuum of space.

"When you remove the water, they quickly coat themselves in large amounts of glassy molecules," Juan de Pablo, professor of molecular engineering at the University of Chicago and one of the authors of a recent study on the tardigrade-inspired glass, said in a statement. The glassy molecules help the microscopic animals stay in a deathlike state of suspended animation as they float through harsh environments, he added. [Biomimicry: 7 Clever Technologies Inspired by Nature]

The tardigrade's ability to produce glasslike molecules under a wide range of temperatures — they can survive temperatures as high as 304 degrees Fahrenheit (151 degrees Celsius) and as low as minus 328 degrees F (minus 200 degrees C) — led the researchers to experiment with the creation of new glass materials under extreme conditions. And this, in turn, led to the development of a glass material that is almost as strange as the creature that inspired its discovery.

Putting things in order

By definition, glasses have an amorphous, or less rigidly defined, molecular structure, than regular, crystalline solids. But the new type of glass created by researchers at the University of Chicago and the University of Wisconsin-Madison defies this definition. Like a crystal, it has a well-defined molecular organization, de Pablo said in a statement.

The new glass, which was described in a paper in the Proceedings of the National Academy of Sciences (PNAS) in March, was produced using a method known as physical vapor deposition. This is a process in which the molecules that will make up the glass are evaporated inside a vacuum and then left to condense, layer by layer, on top of a temperature-controlled substrate, or support structure.

After creating the glass atop the substrate, the researchers analyzed the material using spectroscopic ellipsometry, which measures the way that light interacts with the glass. They found that in some areas within the new glass, the molecules were all oriented in the same way, and, as such, interacted with light in a similar way. [Elementary, My Dear: 8 Elements You Never Heard Of]

Because the structure of glasses is usually random, finding one of these materials that has most or all of its molecules "pointing" in the same direction is rare. And not only is a molecularly structured glass hard to come by, it's also really desirable, according to lead study author Shakeel Dalal, a graduate student at the University of Wisconsin-Madison.

In a post on Reddit's Ask Me Anything (AMA) series, Dalal wrote that, in recent years, researchers who make organic semiconductors using physical vapor deposition — things like light-emitting diodes (LEDs) and solar cells — noticed that they could sometimes produce glass-coated devices with structured, or "oriented" molecules.

"Orientation is great for those applications, because by being able to 'point' the molecule in a direction, you have the ability to improve its ability to carry charge or emit light, for example," Dalal wrote.

When building an LED, getting as much of the light that hits the surface to go "up" and away from the substrate is an engineer's goal. Meanwhile, those who build solar cells want as much light as possible to move "down," toward the substrate, Dalal said.

Until now, semiconductor researchers weren't sure what caused the molecules in glass, in certain instances, to cooperate and point in the same direction. They assumed that certain glass molecules were just better at orienting themselves than others. But the new, tardigrade-inspired research suggests that isn't the case.

Like a tardigrade

The temperature difference between the glass molecules and the substrate where it condensed seemed to drive the orientation of the molecules, the researchers found.

To expand on their preliminary research, de Pablo and colleagues from several institutions in the United States and France recently conducted another series of experimental and model-based tests to see if this temperature finding held true. They found that it does.

"What we have done is to demonstrate that one can create glasses where there is some well-defined organization. And now that we understand the origin of such effects, we can try to control that organization by manipulating the way we prepare these glasses," de Pablo said.

The results of the most recent experiments were published Sept. 1 in the Journal of Chemical Physics.

Follow Elizabeth Palermo @techEpalermo. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

Since 2007, scientists have been exposing tardigrades, commonly called water bears, to outer space in low Earth orbit. These creatures are able to withstand extreme conditions including high pressure, extreme cold and can survive nearly 10 years in a dry state. While they are water-dwelling creatures, these tiny animals are able to suspend growth and go into a state of cryptobiosis meaning they freeze growth and reproduction for a time. These tiny segmented animals are able to survive the trip to and back from space and scientists say they could have come to Earth by hitching a ride on a celestial object.

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Ask anyone to name an Antarctic land animal, and chances are the response will be, "penguin." Try again, says David Barnes, a scientist with the British Antarctic Survey.

"Penguins aren't really residents on land. All the species except for one — emperor penguins — spend most of their lives at sea," Barnes told OurAmazingPlanet.

"And likewise the other sea birds go north during Antarctica's winter," he added.

It turns out that the usual suspects — penguins, seals — don't actually live on the continent. They just visit.

"In order to see Antarctica's resident land animals, you have to have a microscope," Barnes said.

And one look reveals an outlandish cast of characters more suited to Lewis Carroll's fiction than a Disney movie, both in name and ability. The continent's natives — rotifers, tardigrades and springtails, collembola and mites — possess a bizarre array of physiological tools to survive on the coldest, windiest, highest and driest continent on Earth. 

In addition, evidence is mounting that these weird Antarctic animals are remnants of a bygone age, the only survivors of a vanished world — something once thought nearly impossible. 

"The take home message is that we think our animals survived the last ice age," said biologist Byron Adams, a professor at Brigham Young University. 

Petite pachyderms

The largest of the continent's land animals, the so-called "elephants of Antarctica," are the collembola, or, as they are more commonly known, springtails. Unlike the majority of their neighbors, they are visible to the naked eye.

"They look like insects — a little bit like an earwig," said Ian Hogg, a freshwater ecologist and associate professor at New Zealand's University of Waikato. "But they're a lot cuter than earwigs," Hogg added.

Typically under a millimeter long, the tiny, six-legged arthropods are similar to insects, but more primitive, and likely resemble the ancient ancestors of modern-day insects,  Hogg said. They live under rocks near coastal areas, and survive on a diet of fungus and bacteria. Hogg has found them as far south as 86 degrees latitude. [Strangest Places Where Life Is Found]

Although springtails are found all over the planet, those that live in Antarctica have a few tricks to survive the brutal conditions. They can slow down their metabolism to save energy, "and when it gets close to winter, they start to produce glycerol, which lowers their freezing point," Hogg said.

But even springtails can succumb in harsh Antarctic conditions. "If they get too cold they'll freeze solid, and that's the end of them," Hogg said.

They're aliiiive

Yet for Antarctica's most abundant land animal, tiny nematode worms, freezing is not fatal — it's more like a neat party trick.

The hardy worms are one of the most abundant creatures on Earth, and in Antarctica's simple ecosystems, they are king.

"They're the rulers of the continent," said BYU's Byron Adams. "As far as animals go, you're more likely to find a nematode than anything."

The worms may be tiny — a real whopper is almost as long as a dime is thick, Adams said — but they have the combined biological powers of a MacGyver and a Lazarus.

First, the worms employ inventive physiological processes to stave off the effects of the extreme cold.

Like springtails, Antarctica's nematodes can lower their freezing point. They also have a mechanism to protect their cells from the dangers of frozen water, allowing them to survive in temperatures well below freezing.

Inside a cell, ice can be deadly. "Imagine a drop of water," Adams said. "It's smooth and round. When that turns into ice, it turns into a ninja-star type of thing, with all these sharp points. That causes the cells to burst — it kills the cell," he said. This same process causes frostbite and its nasty effects. As cells die, tissue is destroyed.

To prevent this, nematodes produce proteins that act as packing peanuts, surrounding the sharp-edged ice crystals with tiny cushions to protect the cells from rupture and ensuing death.

When conditions get too dry (the worms require moisture to function), the worms have the ability to drop into a death-like state of suspended animation from which they can revive many months, even decades later, when conditions improve.

"They pump all the water out of the bodies until they're dried out like a little Cheerio," Adams said — a process similar to freeze-drying. The worms then literally just blow around in the wind until water returns — often, not until the following summer, when melt from glaciers creates freshwater streams around the continent.

"When the water comes back, the nematodes suck the water back into their bodies and they're re-animated — they come back to life," Adams said.

The strategy is not unique to Antarctica. Nematodes that live in hot, dry deserts do the same thing, he added. [Harshest Environments on Earth]

It's still not clear just how long the worms can survive in this state, but nematodes have reawakened after 60 years in freeze-dried mode.

For all their toughness, the nematodes may have reason to envy one of their Antarctic colleagues — tardigrades — which are similarly rugged, yet have one thing nematodes just haven't got: good looks.

Brawny beauties

"They're really cute," Adams said.

Tardigrades look a bit like a bear crossed with a sweet potato. In fact, they look huggable — a rare quality among microscopic animals. They have chubby bodies and eight legs, from which curved, bear-like claws protrude. 

Like nematodes, these algae-eating water beasts can "freeze-dry" themselves, and have even survived a trip into low-Earth orbit.

"It was quite surprising to me that exposure to the vacuum of space, with its extreme desiccating effect, did not affect survival at all," said Ingemar Jönsson, a professor at Sweden's Kristianstad University, in an email. Jönsson orchestrated the tardigrade space trip aboard a European Space Agency craft in 2007.

Where'd you come from?

The two remaining major Antarctic residents are mites — tiny arachnids that live alongside springtails under rocks — and rotifers, microscopic, slinky-like creatures that dwell alongside nematodes and tardigrades in more moist environments. Although there are many species of each, it's astonishing to essentially be able to count the land animals of an entire continent on one hand.

And although these extreme organisms use a range of biological stunts to survive in Antarctica, they can't live in the ice itself, and it was long accepted that the animals were fairly new arrivals.

"The dogma is that in the last glacial, the continent was totally covered with ice and there was no life," Adams said. "That would mean that all the organisms that live there had to have moved back there since the last glacial maximum — in the last 12 [thousand] to 20 thousand years." That's when retreating ice would have exposed bits of land fit for habitation.

"The problem with that is almost all the animals we find in Antarctica are indigenous to Antarctica," he said. "They're not found anywhere else in the world, and they're not closely related."

Genetic evidence suggests that the continent's residents must have stuck it out through the last glacial maximum. That, in essence, they've been there since 100,000 years ago, when the planet began to cool.

This, along with geological evidence, is changing some of the accepted thinking. Now many Antarctic scientists think the continent wasn't entirely icebound during the last glacial maximum. "We think that there were areas that were exposed, and that these animals survived in little pockets — and once the ice sheets receded, they expanded their range."

Essentially, the crushing cold and lack of moisture killed off the continent's more delicate beasts, and left behind only the hardiest. With almost no competitors for the limited resources, Antarctica's tiny animals were suddenly the smartest guys in the room, able to move out and take over the continent.

Tense future

Even as researchers are learning more about the past of Antarctic wildlife, they are using the continent's residents to peer into the future.

"What is really fascinating about working in Antarctica, is that we can look at the effect of climate change on a single species in the soil," said Diana Wall, a soil ecologist at Colorado State University who has studied Antarctica's tiny animal life for more than two decades.

"We can't do that with a single species anywhere else — the communities are so complex," she said.

Hogg agreed. "Antarctica is such a simple system. The springtails are the biggest things you have to worry about," he said. "And the changes down there happen much more quickly than they will in more temperate latitudes, so it makes it a really fascinating place to look at these changes and how things might respond."

The continent serves as a pristine, natural laboratory, Adams said.

"If you take a sample from a beach in Florida, and you get an anomalous reading, it could be due to anything" he said. "Where we're working in Antarctica, we don't have any of those variables."

Ironically, because Antarctica has no native human population (along with the inevitable environmental footprints we leave behind), it's one of the best places on Earth to study how changing climate will affect the places people do live, Adams said. [Gallery: One-of-a-Kind Places on Earth]

"Someone might say, 'Well, springtails aren't very exciting animals,'" Hogg said. However, he added, studying them and their Antarctic neighbors, which all play a role in cycling nutrients through the environment, can help illuminate how ecosystems closer to home might change with the climate.

"It can help us learn about agricultural systems and the places that we care about and rely on for our daily well-being," he said

"It's very appealing to those of us who are trying to get to the bottom of the fundamentals of the relationship between biodiversity and climate change," Adams said. "This is the one place where we can do these experiments in a natural system."

• Infographic: Antarctica – 100 Years of Exploration
• Creatures of the Frozen Deep: Antarctica's Sea Life
• Image Gallery: Life at the South Pole

Reach Andrea Mustain at amustain@techmedianetwork.com. Follow her on Twitter @AndreaMustain. Follow OurAmazingPlanet for the latest in Earth science and exploration news on Twitter @OAPlanet and on Facebook.