Saturn may be famous for its rings, but it has long fascinated scientists for another reason: its restless atmosphere, which is shaped by fierce winds, stubborn megastorms and strange weather patterns that can linger for years.

Now, two new views from the James Webb and Hubble space telescopes are cutting through the ringed planet's clouds, giving researchers what NASA calls the "most comprehensive view of Saturn to date." Together, the images let researchers "slice" through Saturn's atmosphere at different heights.

The paired observations capture one of Saturn's strangest landmarks: the famous hexagon at the north pole. According to NASA, the faint edges of the six-sided jet stream appear in both images. These pictures could be some of the last high-resolution views of the hexagon until the 2040s, as Saturn's north pole is about to tip into 15 years of winter darkness.

Studying Saturn's atmosphere not only allows scientists to understand how large, planet-size storms grow and thrive but also gives further insight into how the planet formed and evolved over billions of years.

A planet seen two ways

In August 2024, Hubble took its visible-light image of Saturn as part of the Outer Planet Atmospheres Legacy program, a decade-long project that tracks the outer planets annually. The James Webb Space Telescope (JWST) captured its infrared image a few months later, in November 2024. Those observations, taken 14 weeks apart, showed the ringed planet shifting from northern summer toward its 2025 equinox.

The two telescopes saw very different Saturns.

While Hubble captured Saturn's pale-yellow bands and brilliant-white rings, JWST's infrared image revealed even more striking details. In the infrared view, Saturn's rings transformed into glowing blue "because they are made of highly reflective water ice," NASA representatives said in a statement. Saturn's poles also shone a strange gray-green, emitting light at wavelengths of about 4.3 microns. These emissions could be from either light scattering off of high-altitude aerosols or auroras, NASA suggested. (The telescope recently caught giant auroras shining on Uranus.)

As Saturn tilts into its southern springtime, both space telescopes will continue to keep their eyes on its atmosphere, perhaps revealing more about the planet's weather dynamics. Until then, Saturn is keeping some of its most interesting secrets hidden in the clouds.

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Saturn's largest moon, Titan, may be made of two different moons that smashed together hundreds of millions of years ago, a new study suggests. If confirmed, this epic collision could also help to solve several long-standing mysteries surrounding the gas giant, including how its iconic rings formed.

Titan is the solar system's second-largest moon, behind Jupiter's Ganymede. It is around 3,200 miles (5,150 kilometers) across, which is roughly 1.5 times wider than Earth's moon and around 5% wider than Mercury.

Aside from its immense size, Titan is notable for its dense atmosphere, which consists mainly of nitrogen and is around 1.5 times thicker than Earth's atmosphere. It is also the only solar system body, other than Earth, that has confirmed liquid on its surface, in the form of methane — making it a potential candidate for hosting extraterrestrial life. The European Space Agency's Huygens probe touched down on Titan in 2005, making it the only moon, other than our own, that a spacecraft has landed on.

Until now, researchers thought that, like most other moons, Titan formed billions of years ago via the gradual accumulation of tiny chunks of rock and dust. But in the new study, uploaded Feb. 9 to the preprint server arXiv and accepted for future publication in The Planetary Science Journal, researchers from the SETI Institute showed that this may not be the case.

Based on data collected by NASA's Cassini probe, which flew past Titan and deployed Huygens to its surface, the SETI team proposes that Titan may have formed around 400 million years ago when two similarly massive moons slammed into each other.

This collision also may have birthed another Saturnian moon, Hyperion, the researchers argue. This smaller satellite, which is around 84 miles (135 km) wide, likely formed from the debris from the collision, much like Earth's moon did when the protoplanet Theia smashed into Earth around 4.5 billion years ago.

Additionally, the new hypothesis may explain the unusual orbits of several other Saturnian satellites, the team said.

Saturn's missing moon

Saturn has at least 274 moons — the most of any planet — after the recent discovery of 128 natural satellites. However, researchers have long suspected that another massive moon is missing.

Saturn's orbit around the sun is heavily tilted relative to the rest of the planets (excluding its wonky neighbor Uranus), which not only allows us to see the planet's extraordinary rings but also hints that something massive once pulled it out of place. This mystery object was most likely a large moon, which researchers have long suspected was gravitationally slingshotted away from Saturn.

In the new study, researchers explored the possibility that this moon didn't disappear but was instead destroyed.

The "most important clue" that this other moon was destroyed is Hyperion, which is locked in an orbital resonance with Titan, circling Saturn three times for every four of Titan's orbits.

"We recognized that the Titan-Hyperion lock is relatively young, only a few hundred million years old," study lead author and SETI researcher Matija Ćuk said in a statement. "This dates to about the same period when the extra moon disappeared. [So] perhaps Hyperion did not survive this upheaval but resulted from it."

After simulating multiple scenarios from the Cassini data, the team now thinks two massive moons, dubbed "Proto-Titan" and "Proto-Hyperion," smashed into each other, thereby birthing Titan and eventually creating Hyperion from the remnants of the massive collision.

Rings, orbits and automobiles

Hyperion may not have been the only moon created or affected by this potential crash.

The researchers propose that the impact could have birthed several other moons that slowly drifted toward Saturn and collided with other existing satellites, creating a field of debris that eventually settled into Saturn's rings around 100 million years ago. (This hypothesis contradicts a recent study that suggested Saturn's rings are much older than previously realized.)

The study team also theorizes that the collision could explain the wonky orbits of two other Saturnian moons, Iapetus and Rhea, which are significantly tilted compared with their surrounding satellites and somewhat resonate with Titan's orbit.

In addition, their hypothesis could explain Titan's surprising lack of impact craters: Because it is much younger than previously realized, it has been exposed to fewer meteor strikes. The team proposes that, prior to its creation, Proto-Titan may have been covered in pockmarks, similar to Jupiter's moon Callisto.

NASA is preparing to send its Dragonfly probe to visit and explore Titan. The drone-like spacecraft is scheduled to launch in 2028, which would allow it to reach the moon by 2034. When it arrives, it could potentially confirm the collision hypothesis and unravel more of the moon's remaining mysteries.

Saturn's largest moon, Titan, may be hiding a habitable world of slushy sea ice, new research hints.

Back in 2008, NASA's Cassini spacecraft gathered data on Titan that suggested an open ocean might lurk beneath the moon's frozen crust. But the new analysis hints that what lies underneath is instead "slushy tunnels and pockets of meltwater," according to the investigators.

The results, published Wednesday (Dec. 17) in the journal Nature, have large implications for our understanding of how common water is on other worlds. If confirmed, the work may also influence our search for life on other worlds, as water is a key ingredient for life.

"Instead of an open ocean like we have here on Earth, we're probably looking at something more like Arctic sea ice or aquifers, which has implications for what type of life we might find, [and] also the availability of nutrients, energy and so on," study co-author Baptiste Journaux, an assistant professor of Earth and space sciences at the University of Washington, said in a statement.

The "smushing" moon

The story begins with Cassini, a spacecraft that launched in 1997 and spent much of its 20 years observing Saturn and its moons. Cassini spotted the shape of Titan "stretching and smushing" as it circled Saturn, according to the authors of the new study. Back then, the researchers proposed that if Titan possessed a deep ocean, that would let the crust flex under the pull of Saturn's gravity.

Now, the new study takes into account the timing of Titan's flexes. The team found that the shape of Titan begins to change only about 15 hours after Saturn exerts its strongest gravitational pull in Titan's orbit. The scientists then estimated the energy it would take for Titan's shape to alter, which, in turn, showed more about the mysterious moon's interior.

"Nobody was expecting very strong energy dissipation inside Titan," lead study author Flavio Petricca, a postdoctoral fellow at NASA's Jet Propulsion Laboratory, said in the statement. "That was the smoking gun indicating that Titan's interior is different from what was inferred from previous analyses."

Historically, Titan has always been hard to observe. The planet is shrouded in a thick, orange atmosphere that's rich in chemical compounds that may be precursors to life. Looking at the surface requires radar (which Cassini possessed, whereas predecessor flyby missions Voyager 1 and Voyager 2 did not). Cassini's observations revealed a bizarre surface where methane falls as rain, seas constantly shift, and temperatures stand around minus 297 degrees Fahrenheit (minus 183 degrees Celsius).

Titanic slushies

So what is going on in Titan’s interior? The new study says below the frozen exterior, the moon's innards appear to have ice, meltwater pockets and overall, a slushier environment than believed in 2008. The slush is thick and likely accounts for the observed lag in Titan's shape shifts. While water is believed to be in the slush, it wouldn't be as liquid as an open ocean, the team found.

Aside from recycling the old Cassini radio-wave observations, the researchers used new thermodynamic models developed by Journaux's lab to study how water, minerals and other components behave on worlds like Titan.

"The watery layer on Titan is so thick, the pressure is so immense, that the physics of water changes," Journaux said. "Water and ice behave in a different way than sea water here on Earth."

Expanding the search for life

While at first this lack of a full ocean sounds like a blow to the search for life, the research team emphasized that instead, "It expands the range of environments we might consider habitable," Jones said.

Scientists also found that “pockets of fresh water” may exist within Titan at life-friendly temperatures of 68 degrees Fahrenheit (20 degrees Celsius). Moreover, nutrients would be concentrated in small pools of this water, perhaps allowing for more rich conditions for life than a less-concentrated ocean would.

Upcoming observations may aid our understanding of Titan. NASA's Dragonfly mission is set to launch as soon as 2028, and it should arrive at Titan in 2034. It will be the second flying vehicle on another world besides Earth, after Ingenuity, a helicopter on Mars. It is hoped that Dragonfly's surface observations of Titan will reveal more about where life may be lurking and how much water might be available for organisms.

The frigid conditions on the surface of Saturn's largest moon, Titan, allow simple molecules in its atmosphere to break one of the most fundamental rules in chemistry, a new study shows.

According to this principle, known as "like dissolves like," mixtures containing both polar and nonpolar components, such as oil and water, usually don't mix and instead form separate layers.

But scientists from NASA's Jet Propulsion Laboratory and the Chalmers University of Technology in Sweden were surprised to discover that the polar molecule hydrogen cyanide forms stable co-crystals with the extremely nonpolar hydrocarbons methane and ethane on Titan's frigid surface — molecules that are normally entirely incompatible on Earth.

"This contradicts a rule in chemistry, 'like dissolves like,' which basically means that it should not be possible to combine these polar and nonpolar substances," lead study author Martin Rahm, an associate professor of chemistry, biochemistry and chemical engineering at the Chalmers University of Technology, said in a statement.

The new study, published July 23 in the journal PNAS, challenges a long-held pillar of chemistry and could open the door to the discovery of more exotic solid structures across the solar system.

Re-creating Titan's surface

Conditions on Titan's surface bear a striking resemblance to those of early Earth, research suggests. Its atmosphere contains high levels of nitrogen and the simple hydrocarbon compounds methane and ethane, which cycle in a localized weather system, much like Earth's water cycle.

However, until now, researchers were unsure about the fate of the hydrogen cyanide produced by reactions in this atmosphere. Is it deposited on the surface as a solid? Does it react with its surroundings? Or could it be converted into the first molecules of life?

To investigate these questions, the NASA team replicated the conditions on Titan's surface by combining mixtures of methane, ethane and hydrogen cyanide at temperatures of around minus 297 degrees Fahrenheit (minus 183 degrees Celsius). A spectroscopic analysis — a way of studying chemicals through their interactions with different wavelengths of light — yielded unexpected results, suggesting that these contrasting compounds were interacting much more closely than had ever been observed before.

It appeared that molecules of nonpolar methane and ethane had slotted into gaps in the solid crystal structure of the hydrogen cyanide — a process known as intercalation — to create an unusual co-crystal containing both sets of molecules.

Ordinarily, polar and nonpolar molecules don't mix. Polar compounds, such as water and hydrogen cyanide, have an uneven distribution of charge across the molecule, creating some areas that are slightly positive and others that are slightly negative. These oppositely charged regions are attracted to each other, forming strong intermolecular interactions between the different polar molecules and largely ignoring any nonpolar components.

Meanwhile, nonpolar oils and hydrocarbons have an entirely symmetrical arrangement of charge and interact very weakly with neighboring nonpolar molecules and not at all with polar particles. As a result, mixtures containing both polar and nonpolar components, such as oil and water, usually form distinct layers.

To explain their bizarre observations, the NASA team joined forces with researchers at the Chalmers University of Technology to model hundreds of potential co-crystal structures, assessing each for its probable stability under the conditions on Titan.

"Our calculations predicted not only that the unexpected mixtures are stable under Titan's conditions but also spectra of light that coincide well with NASA's measurements," Rahm explained.

Their theoretical analysis identified several possible stable crystal forms, which they propose are stabilized by a surprising boost in the strength of the intermolecular forces in the hydrogen cyanide solid triggered by this mixing.

Their rigorous combination of theory and experiment impressed Athena Coustenis, a planetary scientist at the Paris-Meudon Observatory in France. She is excited to see how future data, including that from NASA's Dragonfly probe (due to arrive on Titan in 2034), will complement the study's findings.

"Comparing laboratory spectra with upcoming Dragonfly mission data may reveal signatures of these solids on Titan's surface, providing insight into their geological roles and potential importance as low-temperature, prebiotic reaction environments," Coustenis told Live Science in an email. Further work could even expand this approach to other molecules likely generated by Titan’s atmosphere, including cyanoacetylene (HC₃N), acetylene (C₂H₂), hydrogen isocyanide (HNC), and nitrogen (N₂), she said. “[This] will test whether such mixing is a general feature of Titan's organic chemistry."

In a universe where change usually unfolds over eons, astronomers have gotten a rare front-row seat to watch a small, icy world beyond Saturn build a brand-new set of rings in real time.

A team of Brazil-based astronomers found that the bands of material orbiting around (2060) Chiron, a 125-mile-wide (200 kilometers wide) object that circles the sun between Saturn and Uranus, are new and still taking shape. The findings suggest that Chiron's surroundings are in a transitional state somewhere between a chaotic cloud of debris and a fully formed ring system, offering scientists a rare snapshot of ring formation in progress, which has never been directly witnessed before.

"It was an exciting surprise," Chrystian Pereira, a postdoctoral researcher at the National Observatory in Brazil who led the study, told Live Science. "In a way, it reminds us that the solar system is alive and continuously evolving, even on human timescales."

Chiron joins the asteroid Chariklo and dwarf planets Haumea and Quaoar as one of only four small worlds in our solar system known to host rings, but it may be the most dynamic of them all.

Chiron's changing environment, detailed in a paper published Oct. 14 in the Astrophysical Journal Letters, could help scientists understand how both small icy objects as well as giant planets like Saturn and Uranus built their iconic rings billions of years ago.

Rings in the making

Composed of rock, water ice and organic compounds, Chiron belongs to a strange population of objects called centaurs, which orbit between Jupiter and Neptune and behave partly like asteroids and partly like comets. Chiron orbits the sun once every 50 Earth years.

Since its discovery in 1977, astronomers have seen it occasionally brighten and even sprout a faint tail, evidence that it sometimes vents gas and dust into space.

In September 2023, when Chiron briefly crossed in front of a distant star from Earth's point of view, the Pico dos Dias Observatory in Brazil detected tiny, repeated dips in the star's light. When the researchers compared this data to similar events cataloged in 2011, 2018 and 2022, they found that the three distinct, dense rings — orbiting at a distance of about 170 to 270 miles (270 to 430 km) from Chiron's center — had stayed in place for more than a decade.

In the 2023 data, the team also spotted a new disk-like structure stretching from about 120 miles up to 500 miles (200-800 km) around Chiron that hadn't appeared in previous data. The broader, diffuse disk likely formed only within the past decade, possibly from a collision or outburst that released fresh material into orbit, said Pereira.

Intriguingly, the team also discovered a faint outer feature nearly 870 miles (1,400 km) from Chiron — well beyond what's known as the Roche limit, the boundary where ring material should clump together into a moon rather than stay as debris, the new study notes.

"This is the first time we've detected any signature of material in that region," Pereira told Live Science, adding that higher-resolution observations are needed to confirm it. "Beyond that limit, particles forming a ring should naturally begin to coalesce into a satellite — yet something seems to be preventing that from happening."

The researchers aren't certain what caused Chiron's strange setup. One possibility is that volatile ices beneath its surface erupted in a comet-like outburst, ejecting dust and ice that later settled into orbit. Another is that a small moon shattered, scattering fragments that spread along Chiron's equator, according to the new study.

The latter theory could also explain Chiron's steady brightening over the past decade, which is hard to account for through cometary activity alone, Pereira said.

Other experts say the findings raise new questions about how rings around small bodies can survive for long periods.

"It may be that something is adding energy to these particles and allowing them to persist outside the limit without coalescing," Keighley Rockcliffe, a postdoctoral researcher at NASA Goddard Space Flight Center in Maryland who was not involved in the new paper, told Live Science via email.

It could also be that the ring is very diffuse or that it simply hasn't existed long enough to coalesce, Rockcliffe said. "Maybe it's recently formed and it hasn't had the chance to form a little centaur-let."

To confirm whether Chiron's rings are truly evolving, and not just appearing different from our changing vantage point, astronomers hope to capture more events in which Chiron passes in front of distant stars. Such events, when recorded with high-speed cameras at observatories across multiple continents, are the only direct way to see if the disk's material is changing in opacity, width, or position — signs that, according to Pereira, would reveal the dust and ice are being actively redistributed, offering direct evidence of ongoing evolution.

"The ideal scenario to satisfy our curiosity, however, would be a space mission dedicated to in-situ observation of this intriguing system," Pereira said.

Scientists have discovered that the molecular building blocks needed for life are "readily available" on Saturn's icy moon Enceladus.

At only 314 miles (505 kilometers) wide, Enceladus could fit inside Colorado — and thanks to its liquid water, hydrothermal energy source and chemical tool kit, it has the potential to host extraterrestrial life.

Twenty years ago, NASA's Cassini spacecraft discovered evidence that a vast salty ocean hidden beneath Enceladus' surface was spitting out minuscule "ice grains" through cracks near the moon's south pole. Subsequent studies have spotted five of the six essential elements for life — carbon, hydrogen, nitrogen, oxygen and phosphorus (only missing sulfur) — within these grains.

However, the majority of these past studies looked at the relatively old ice grains that settled in Saturn's E ring — a diffuse ring outside the planet's bright main rings — after being ejected decades or centuries prior. This meant scientists couldn't be sure that the compounds truly came from Enceladus rather than from space weathering in the ring.

Now, astronomers have identified organic molecules, perhaps including nitrogen and oxygen, in fresh ice grains sprayed from Saturn's icy moon. The new research was published Wednesday (Oct. 1) in the journal Nature Astronomy.

Secrets of the ice moon

In 2008, as Cassini shot through a geyser of freshly spewed-up ice grains from Enceladus, it collected data on the splatter that covered the spacecraft's Cosmic Dust Analyzer. These grains hit the spacecraft at 11 miles per second (18 kilometers per second), which was so fast that the water molecules didn't cluster. This meant the team could see "previously hidden signals," study co-author Nozair Khawaja, a planetary scientist at the Free University of Berlin, said in a statement.

The researchers used mass spectrometry to analyze the chemical fingerprint of the molecules in the fresh ice grains. They found chemical compounds that, on Earth, are involved in reactions that lead to the formation of complex molecules required for life, including structures potentially containing nitrogen and oxygen.

"These molecules we found in the freshly ejected material prove that the complex organic molecules Cassini detected in Saturn's E ring are not just a product of long exposure to space, but are readily available in Enceladus's ocean," study co-author Frank Postberg, a professor of planetary science at the Free University of Berlin, said in the statement.

Nozair said there are various ways these molecules could become biologically relevant, "which enhances the likelihood that the moon is habitable." Even so, he said it would still be a huge discovery to not find any life on Enceladus because it would raise "serious questions about why life is not present in such an environment when the right conditions are there."

ESA is planning a future mission to land a spacecraft on the southern pole of Enceladus to collect more samples. The agency is targeting the early 2040s as the earliest possible launch date.

The James Webb Space Telescope has discovered strange "dark beads "above a four-armed star pattern in Saturn's atmosphere. The surprising structures are unlike anything scientists have seen before, and they're not sure what they are.

The unusual features were discovered by the James Webb Space Telescope's (JWST's) Near Infrared Spectrograph (NIRSpec) as it peered into the gas giant's atmosphere above the hexagonal storm that swirls at the planet's north pole.

The astronomers expected to see emissions across broad bands of the infrared spectrum in the atmospheric layers above the vortex. Yet what they noticed instead were dark, bead-like features — separated by vast distances yet possibly interconnected — drifting slowly in the charged plasma of the planet's ionosphere, and a lopsided star-shape structure in the stratosphere beneath. They published their findings Aug. 28 in the journal Geophysical Research Letters.

"The results came as a complete surprise," Tom Stallard, a professor of astronomy at Northumbria University in the U.K., said in a statement. "These features were completely unexpected and, at present, are completely unexplained."

Saturn's Hexagon was first discovered in 1980 by NASA's Voyager spacecraft and imaged in fine detail by the Cassini spacecraft, which orbited the planet from 2004 to 2017. It rises as an 18,000-mile-wide (29,000 kilometers) six-sided tower whirling above the planet's surface, making a complete rotation roughly once every 10 hours.

Scientists believe that the hexagon is driven by a jet stream circling the planet's pole, and owes its unique shape to the properties of the gases in Saturn's atmosphere. Yet the exact reasons it has this flow and shape aren't known for certain; and neither is the behavior of the upper atmosphere above it, due to the very weak emissions coming from it.

To investigate, the astronomers focused JWST's NIRSpec instrument on Saturn's ionosphere and stratosphere, located 684 miles (1,100 km) and 373 miles (600 km) above the planet's nominal surface, respectively.

Related: Saturn will be at its biggest and brightest on Sept. 21 — here's how to see it

Over 10 hours, the telescope tracked positively-charged hydrogen molecules (H3+, involved in many reactions in the planet's atmosphere) across Saturn's ionosphere and methane molecules throughout its ionosphere, revealing the strange structures.

"We think that the dark beads may result from complex interactions between Saturn's magnetosphere and its rotating atmosphere, potentially providing new insights into the energy exchange that drives Saturn's aurora," Stallard said.

The asymmetric star pattern, meanwhile, may somehow be tied to the hexagonal storm pattern, he said.

"Tantalisingly, the darkest beads in the ionosphere appear to line up with the strongest star-arm in the stratosphere, but it's not clear at this point whether they are actually linked or whether it's just a coincidence," he added.

To understand what could be causing the features, and their effects on Saturn's atmosphere, the team hopes to conduct followup observations with JWST. Saturn is currently at its equinox, meaning the patterns could change drastically as the sun shifts across the planet's face. On Sept. 21, the ringed planet will also be at its closest point to Earth — the best time to observe Saturn with telescopes and to attempt to parse its many mysteries.

The best time to view Saturn is almost here: On Sept. 21, the ringed planet will reach opposition, meaning Earth will be positioned directly between Saturn and the sun. (In other words, it is on the opposite side of Earth as the sun.) At that moment, the sun, Earth and Saturn will form a straight line.

During opposition, Saturn will appear to be at its biggest and brightest because the planet will be at its closest point to Earth. Similar to a full moon, Saturn will seem to be fully illuminated by the sun's rays because of its position relative to the sun. This event happens just once every 378 days, so you won't want to miss this opportunity to see it.

When Saturn reaches opposition, viewing conditions will be ideal. On Sept. 21, the moon will be in its new phase, so moonlight won't threaten to wash out objects in the night sky. And because Saturn will be directly opposite the sun, the planet will be visible all night, rising in the east around sunset and setting in the west around dawn local time, according to Earth Sky.

To make these viewing conditions even better, observe Saturn away from sources of artificial light, which can wash out objects in the night sky and make skywatching more difficult. You'll also want to allow 15 to 30 minutes for your eyes to adjust to the dark before you begin your observations. If you must use a flashlight, choose red light instead of white light to preserve your night vision.

Saturn will appear at the bottom of the constellation Pisces. Because the ringed planet is quite bright, it's easy to spot in the night sky. But if you need help locating Saturn, you can use a skywatching app like Stellarium.

The best way to view Saturn is through a pair of skywatching binoculars or a backyard telescope. Through skywatching equipment, you can observe Saturn's stunning rings, which undergo a dramatic brightening known as the Seeliger effect.

Related: A 'crescent sunrise' solar eclipse is coming this weekend. Here's where to see it.

When Saturn reaches opposition, the rings appear much brighter than normal because the direct sunlight reflects off the rings and eliminates shadows among the countless particles that make up Saturn's rings, according to Astronomy Magazine. The Seeliger effect lasts a few days around the time Saturn reaches opposition.

Although the precise moment of opposition centers on Sept. 21, it takes Saturn a couple of weeks to approach and leave its position in the opposite part of the sky from the sun. So if you can't see Saturn on the 21st, you still have some time to view the ringed planet at its biggest and brightest a day or two before and after that date.

Saturn happens to reach opposition this year on the same day that a partial solar eclipse will be visible from parts of Antarctica, Australia and New Zealand. The next day, Sept. 22, marks the autumn equinox in the Northern Hemisphere, when Earth’s seasons change and progressively longer nights for skywatching begin in the North.

Who hasn't looked into the sky and wondered if there's life out there, somewhere, looking back at us? Is it possible there's alien life closer to home — within the bounds of our solar system?

The short answer is yes, there are several places researchers are looking for signs of life within our solar system, and there are some hints that life might be hiding in unexpected places.

Is there life on Mars?

While there don't seem to be any "little green men" inhabiting Mars, it's possible there was microbial life in the past. Mars is currently a frigid desert, but thanks to Mars rovers that have studied the planet's rocks, we know that a long time ago, it had liquid water — an important condition for life.

"The Curiosity rover was built to search for habitable environments, the kind that could have supported microbial life on Mars in the past, if life ever arose on the Red Planet," said Amy Williams, a geology professor at the University of Florida and a member of both NASA's Curiosity and Perseverance science teams. "Curiosity's payload was selected to accomplish this task by looking for the conditions that we know life on Earth requires — liquid water, a source of carbon, and chemical energy to power a metabolism," she told Live Science.

In addition to studying the Martian environment, the Perseverance rover has been collecting promising rock samples to be returned to Earth for advanced analysis. The Mars Sample Return mission is currently under development by NASA and ESA to travel to Mars, collect the sample cores, and bring them back to Earth. (The Donald Trump administration has proposed cutting NASA funding to pay for this mission, however.)

"At least one of the cores collected has qualities that fit the definition of a possible indicator of ancient microbial life," Williams said of a particularly interesting rock sample. "Returning samples to Earth with the Mars Sample Return architecture would enable us to address some of humanity's most profound questions, including whether we are alone in the universe."

Related: How would we give aliens directions to Earth?

Could there be life on Venus?

Even though it's commonly called Earth's "twin," Venus is probably not the first place anyone might look for life in the solar system. Its surface temperature is hot enough to melt lead, and the average surface pressure is more than 90 times that of Earth. It's wrapped in thick, dense clouds that are mostly made from sulfuric acid, a highly corrosive substance that mixes with water to form acid rain on Earth, damaging flora, fauna and soil.

Despite those hostile conditions, extremophile microbial life might be able to survive high in Venus' atmosphere, where the temperatures and pressures aren't so extreme; perhaps life could find ways to protect itself from sulfuric acid's destructive nature. To find out, MIT is putting together the Morning Star Missions, which will travel to Venus' atmosphere with the ultimate goal of collecting a sample of the planet's clouds and returning it to Earth for better analysis.

"Microbial life might exist in Venus's clouds, despite their composition of concentrated sulfuric acid," Sara Seager, a professor at MIT and the director of the Morning Star Missions, told Live Science. "If we find compelling signs of life on Venus, it would upend our understanding of habitability and prove that life can exist in non-water solvents, opening up the range of worlds where life is possible."

When looking for life, scientists often focus on the search for liquid water because it's a requirement for life on Earth. Finding life on Venus would shatter that limitation — meaning alien life could be a lot stranger than we've thought and there could be a lot more places to look for it.

In 2020, a possible detection of phosphine gas in Venus' clouds became the center of a controversy about signs of life on Venus. Phosphine gas was an unexpected find because most known chemical processes that produce it come from living organisms or from extreme pressures on gas giants. However, the signal was small and critics said it might have been noise in the data. The Morning Star Missions to Venus will give us much more information about the planet's chemistry and possibly confirm if there's phosphine floating in the clouds.

Is there life on the moons of Saturn and Jupiter?

Further out in the solar system, there are several moons orbiting Saturn and Jupiter that could potentially host life, particularly Enceladus and Europa.

Saturn's moon Enceladus has a global subsurface ocean hiding underneath a thick icy shell. The moon constantly spits giant plumes of salty water into space that give scientists a rare opportunity to directly sample the interior of a celestial body other than Earth. The Cassini mission performed several flybys of Enceladus from 2005 through 2017, collecting images and even direct samples from the plumes that are still being analyzed. A 2023 paper in Nature announced that scientists had detected phosphates on Enceladus — meaning scientists have now detected all the basic chemical ingredients for life in the moon's ocean.

Several missions to study astrobiology on Enceladus, with the goal of collecting more samples from the plumes, have been in the works by teams at ESA and NASA, although they're still a long way from getting to the launch pad.

Like Enceladus, Jupiter's moon Europa is an icy world with a global subsurface ocean and water plumes erupting from its surface. Jupiter's massive gravitational pull on the moon provides energy and motion that fuels active geologic activity, and is thought to be the main reason the ocean is warm enough to be liquid. Interactions between the salty ocean and the rocky interior could possibly host life similar to the life found around hydrothermal vents on Earth.

ESA's Jupiter Icy Moons Explorer (Juice) launched on April 14, 2023 with an expected arrival at Jupiter in July 2031, where it will study Jupiter and three of its moons: Europa, Callisto and Ganymede. NASA's Europa Clipper mission launched on Oct. 14, 2024 to reach Jupiter in 2030 and conduct flybys of Europa to study if conditions for life are present.

Titan, another of Saturn's moons, is an extremely unique place in the solar system. It has a methane cycle like Earth's water cycle and a thick nitrogen and methane atmosphere. The Cassini mission performed over 50 flybys of Titan from 2004 through 2017 and launched the Huygens probe that landed on the moon's surface in 2005. These two missions collected data that indicated Titan's atmosphere could probably create complex molecules that are building blocks for life. NASA is putting together a car-sized octocopter to fly on Titan and collect samples at different landing sites.

Where else could life be in the solar system?

There are quite a few other places we might find life in the solar system, including dwarf planets like Ceres. Ceres is thought to have a lot of liquid water under an icy and rocky crust, thanks to images taken by NASA's Dawn mission which visited it in 2015.

The more we explore the solar system, the more places we find that have conditions that could support life. If there is life out there, it's likely not advanced enough to reach out to us, so we'll have to be the first to say hello.

Extraterrestrials quiz: Are you an alien expert, or has your brain been abducted?

Six planets — Mercury, Venus, Jupiter, Saturn, Uranus and Neptune — will appear in a dark night sky together for almost a week, beginning Sunday, Aug. 17. The fairly rare "planetary parade," which is sometimes mistakenly called a planetary alignment, will continue through Wednesday, Aug. 20.

The celestial gathering, last seen in February, will appear in the eastern sky about an hour before sunrise. Although most of these planets have been visible in the morning sky for weeks, Mercury will join the fray, bringing the planet count from five to six.

Under clear skies, you should be able to spot Venus, Jupiter and Saturn. Mercury will be closer to the horizon but still bright enough to be seen by most observers. However, Uranus (appearing between Jupiter and Saturn in the sky) and Neptune (close to Saturn in the sky) are too dim and distant to be seen with the naked eye. The only way to see these two ice giants is by using a good telescope.

Although it's relatively rare for six planets to appear in the sky simultaneously, the beauty of the view will be vastly increased by the waning crescent moon.

Related: How to photograph the moon: Tips on camera gear, settings and composition

On Aug. 17 and Aug. 18, a crescent moon will rise above Jupiter and Venus. The two brightest planets in the night sky are now slowly moving apart after an incredibly close conjunction on Aug. 12.

Mercury may be visible below Jupiter and Venus, but it will be easier to see it on Aug. 19. On that morning, and on Aug. 20, a slim crescent moon will be very close to Jupiter and Venus — a visual highlight of the "planetary parade."

By around Aug. 21, Mercury will begin to fall back into the sun's glare and will become more difficult to see.

According to the Star Walk app, there will be two six-planet parades in 2026: one after sunset in February and another before sunrise in August.

Over the next few months, there will be several chances to see a giant "hole" shoot across the surface of Saturn, as the shadow of its largest moon passes across the ringed planet's Earth-facing surface. The rare spectacle will not be visible again until 2040 — and we'll tell you how to see it from your backyard.

Every 15 years, Saturn and Earth become perfectly aligned so that the gas giant's rings face our planet head-on. In March, this alignment was so perfect that the planet's super-thin rings completely disappeared from view, Live Science's sister site Space.com previously reported. In 2032, the opposite will occur, and we will be able to see the entirety of the dusty disks in a perfect circle around the fifth planet from the sun.

Saturn's current orientation also means that the planet's largest moon, Titan, circles it in a way that causes its large shadow to repeatedly transit the planet's surface, similar to how the moon's shadow races across Earth during a lunar eclipse. The same phenomenon also happens to some of Saturn's other major moons, including Mimas and Rhea. However, their respective shadows are smaller and lighter than Titan's, making it harder to see them.

Titan orbits Saturn roughly every 16 days, meaning that there will be a total of 10 transits visible while Earth is still aligned with the ringed gas giant. Three of these transits have already happened, most recently on June 16. But there are still seven more occasions when the spectacle could be visible between now and mid-autumn, depending on your location and weather conditions at the time.

The remaining transits will occur on July 2, July 18, Aug. 3, Aug. 19, Sept. 4, Sept. 20 and Oct. 6, according to Sky & Telescope. For exact times, check the table below.

Related: Saturn gains 128 new moons, giving it more than the rest of the solar system combined

Titan will also be visible during these transits, although its position relative to the shadow changes with each viewing, as Saturn continues to circle the sun. But it will be slightly smaller than the shadow it casts.

To see the spectacular transits for yourself, you will need a good telescope with at least 200x magnification. From North America, most of the transits will start and end before sunrise. To find where Saturn will be in the night sky, you can use websites such as TheSkyLive.com.

However, we recommend that you don't leave it to the last minute, because adverse weather conditions could completely obscure your view. As you can see from the table below, the length of transits will also decrease each time, which means you will have to be more precise with your timings later in the year; On Oct. 6, the shadow will only be momentarily visible when Titan is exactly at mid-transit.

But even if you miss the impressive shadow over the next few months, you will still be able to see Titan pass in front of Saturn every 16 days, up until January 2026, when it will stop transiting the planet until 2040.

If you are lucky enough to see the stunning celestial spectacle, be sure to keep in mind that Titan is the second-largest moon in the solar system, behind Jupiter's behemoth satellite Ganymede. At more than 3,200 miles (5,150 kilometers) across, it is also slightly bigger than the planet Mercury and 50% wider than Earth's moon.

It is also the only one of the solar system's moons, other than Earth's, that has been visited by a human-made spacecraft. The European Space Agency's Huygens probe landed on the Saturnian satellite in 2005 — and it is still there today.

Solar system quiz: How well do you know our cosmic neighborhood?

The James Webb Space Telescope (JWST) has captured its first direct image of a planet in a remote solar system, and it's lighter than any seen before.

The planet, named TWA 7b, is a gas giant with a size comparable to Saturn's. Orbiting a star just over 6 million years old, the planet is still glowing hot from its formation.

The planet is the first observation of hypothesized yet previously unseen "shepherd" planets, which clear gaps of material found inside planetary rings. The researchers behind the discovery published their findings June 25 in the journal Nature.

"It tells us that indeed, planets can form gaps in disks (which was theorised, but not observed) and trojan-like structures can indeed be present in exoplanetary systems," lead study author Anne-Marie Lagrange, an astronomer and research director at the French National Center for Scientific Research (CNRS) in Paris, told Live Science.

"It is the first time that such a light planet is imaged, ten times lighter than the lightest [previously known] planet," she said. "This is thanks to the extreme sensitivity of JWST in the thermal domain."

Astronomers study exoplanets because they help them to understand how planetary systems, such as our own, form. Yet while thousands have been seen indirectly — through the dimming of host stars as they pass in front of them or the wobble the planets' gravitational tugs give them — the light bouncing off exoplanets is usually drowned out by the light from the star, making them effectively invisible.

Related: 'Eyeball' planet spied by James Webb telescope might be habitable

To peer through this glare, JWST uses a coronagraph attached to its Mid-Infrared Instrument (MIRI); this device blocks out a star's light and makes it easier to spot objects orbiting around it. To further boost the effectiveness of this search, astronomers select young stars whose planetary disks are pole-on to the telescope, enabling them to “look down” over star systems whose satellites are still glowing hot from their formation.

The system containing TWA 7b, called TWA 7, is 110 light-years from Earth and contains three concentric rings of rocky debris and dust, one of which was narrow and flanked by two empty bands of space. Within the heart of this narrow ring, the scientists found a hole containing a source of infrared-radiation.

Follow-up simulations suggested that this radiation source is a planet roughly 30% the size of Jupiter that's orbiting its star at 52 times the distance that Earth orbits the sun. Its presence in a gap inside the planetary ring is also intriguing; while observations of holes in the discs surrounding stars have been made before in other systems, this is the first clear detection of the shepherd planets believed to create them.

To further investigate the new system and others like it, Lagrange said that she and her colleagues will obtain "more data to study TWA7 b atmosphere, to search for other light, cold young planets in imaging" and "to search for cold old massive planets."

When you think of a planet with rings, majestic Saturn almost definitely comes to mind. But it's not the only planet in the solar system with these breathtaking bands. So which planets in our solar system have rings?

All four giant planets — Jupiter, Saturn, Uranus and Neptune — sport these spectacular structures. Plus, many other objects in the solar system, including the dwarf planet Haumea and asteroid Chariklo, have rings. Whether or not we can see these rings easily from Earth depends on what they're made of.

Unlike a diamond ring, planets' rings don't last forever — not even the most iconic ones in the solar system. Scientists think Saturn's rings will vanish as the debris that makes up the rings falls into Saturn's atmosphere, but that won't happen for a long time.

"We still have hundreds of millions of years to enjoy them," Saunders said. "But it makes me think about how lucky we are to live at a time when Saturn has beautiful, icy, visible rings."

Scientists have known for a while that Saturn's largest moon, Titan, has rivers and seas of liquid methane on its surface. But it's strangely lacking in deltas, a new study suggests.

On Earth, large rivers create deltas with sediment-filled wetlands. Deltas form when the mouth of a river empties into another body of water. Besides Earth, Titan is the only planetary body in our solar system with liquid flowing on the surface.

Researchers recently looked for deltas on the big Saturn satellite but came up empty.

"We take it for granted that if you have rivers and sediments, you get deltas," study leader Sam Birch, an assistant professor in the Department of Earth, Environmental and Planetary Sciences at Brown University in Rhode Island, said in a statement.

"But Titan is weird. It's a playground for studying processes we thought we understood," he added.

Related: Space photo of the week: Look into Titan's 'eye,' 20 years after the Huygens spacecraft's historic landing on Saturn's largest moon

The researchers were hoping to find deltas on Titan, because these landforms feature lots of sediment. The sediment in deltas tends to come from a large area, and deltas gather it in one place. Studying such sediment could reveal insights about Titan's climate and tectonic histories — and perhaps even possible signs of alien life.

"It's kind of disappointing as a geomorphologist, because deltas should preserve so much of Titan's history," Birch said.

We know that Titan's surface has flowing liquid methane, because NASA's Cassini spacecraft spotted evidence of the stuff on multiple flybys. Cassini used synthetic aperture radar (SAR) to look through Titan's thick atmosphere during these close encounters and found channels and large flat areas that are consistent with large bodies of liquid.

But shallow liquid methane is largely transparent in Cassini's SAR data. Scientists have therefore had a hard time studying Titan's coastal features, because it's hard to make out where the coast ends and the sea floor starts.

So, Birch's team came up with a computer model that simulates what Cassini's SAR would see when looking at Earth. But the model replaced the water in Earth's rivers and oceans with Titan's liquid methane.

"We basically made synthetic SAR images of Earth that assume properties of Titan's liquid instead of Earth's," Birch said. "Once we see SAR images of a landscape we know very well, we can go back to Titan and understand a bit better what we're looking at."

The synthetic SAR images of Earth that they created "resolved large deltas and many other large coastal landscapes," according to the researchers.

They say that new analysis of the Cassini SAR data also revealed other mysteries. For example, Titan's coasts appear to have pits of unknown origin deep within lakes and seas, and deep channels cut across the moon's sea floors offer no clue to how they got there.

"This is really not what we expected," Birch said. "But Titan does this to us a lot. I think that's what makes it such an engaging place to study."

The new study was published in the Journal of Geophysical Research: Planets on March 25.

Originally posted on Space.com.

With its beautiful rings, Saturn may be the most stunning planet in the solar system. It is the sixth planet from the sun and the second-largest planet in the solar system, after Jupiter.

Though Saturn is famous for its rings, all of the other giant planets — including Jupiter, Uranus and Neptune — have ring systems. But Saturn stands out for having beautiful yellow and gold bands across its surface, as well as for hosting more moons than any other planet in the solar system. In fact, some of Saturn's moons are among the best places to search for life outside Earth.

5 fast facts about Saturn

• Saturn is the farthest planet from Earth that is still visible with the naked eye in the night sky.
• The name "Saturn" comes from the Roman god of wealth and agriculture.
• A day on Saturn lasts 10.7 hours, but a year on Saturn lasts 29.4 Earth years.
• It takes 80 minutes for sunlight to travel to Saturn.
• Saturn is less dense than water, so it could float in a (very large) bathtub.

Everything you need to know about Saturn

Saturn pictures

Discover more about Saturn

—What are Saturn's rings made of?

—There's a weird, disappearing dark spot on Saturn's moon Enceladus

—100-year-long 'megastorms' on Saturn are creating radio signals that scientists can't fully explain

If you look up to the sky in the early hours of April 25 you might just see it smiling back at you, NASA skywatchers have forecast.

That's when a rare celestial spectacle called a triple conjunction will occur. On the morning of Friday, April 25, Venus, Saturn and the crescent moon will appear close together in the predawn sky, forming a triangular formation reminiscent of a smiley face. You can spot the celestial spectacle close to the eastern horizon just before sunrise, according to NASA. Both planets are bright and easily seen with the naked eye, but a good backyard telescope or stargazing binoculars can help you pick out details on the smirking crescent moon.

Mercury may also be visible below the twinkling trio for those with a clear view of the horizon, according to NASA. Unlike the larger planets, it will appear very low in the sky, so may not be visible everywhere.

What is a triple conjunction?

In astronomy, a conjunction occurs when two or more celestial objects appear very close to each other in the night sky. When three objects are involved, it becomes a triple conjunction.

"Venus is higher above the eastern horizon with Saturn lower, and a thin, crescent Moon a bit lower and a little farther north," NASA Solar System Ambassador Brenda Culbertson told local Kansas TV station KSNT. "The thin, crescent Moon looks like a smile. To some people, the triangle of bright objects may appear as a smiley face."

Related: The 10 best stargazing events of 2025

The face will be visible from anywhere in the world with good viewing conditions, although the window in which to watch it will be narrow — Culbertson said that the alignment will slide into place at around 5:30 a.m on April 25 and the sun will rise around an hour later.

"Anyone wanting to try for a glimpse of the conjunction should find a clear eastern horizon from which to observe," Culbertson said.

The conjunction will light up the skies just days after the Lyrids meteor shower peaks. The shower is ongoing, but the peak can be seen anytime between 10:30 p.m. and 5 a.m. local time from April 21 to 22, with little interference from the waning crescent moon. According to NASA, up to 15 meteors will be visible per hour under dark skies.

Astronomers have discovered 128 never-before-seen moons orbiting Saturn — giving it almost twice as many moons as all the other planets in the solar system combined.

The findings have further bolstered Saturn's status as our solar system's "moon king." With an updated total of 274 known natural satellites orbiting the gas giant, it is leagues ahead of its main competitor Jupiter, which has just 95 confirmed moons.

This week, the International Astronomical Union officially recognized the team's discovery. The researchers published their findings March 10 in the journal arXiv, so they have not yet been peer-reviewed.

"Our carefully planned multi-year campaign has yielded a bonanza of new moons that tell us about the evolution of Saturn's irregular natural satellite population," study lead author Edward Ashton, an astronomer at Institute for Astronomy and Astrophysics at Academia Sinica, Taiwan, said in a statement.

The newfound moons are situated within the Norse group of Saturn's moons — a group of moons that orbit in retrograde (travelling in the opposite direction to the planet’s rotation) along elliptical paths outside Saturn's rings. The 128 newly discovered objects are considered "irregular" moons, meaning they're only a mile or two in size and far from spherical.

Related: NASA finds key ingredient for life gushing out of Saturn's icy moon Enceladus

Their diminutive sizes and location means these moons are likely fragments of larger moons that were smashed apart by a cataclysmic collision — probably with Saturn's other moons or a passing comet. This collision could have occurred as recently as 100 million years ago, the astronomers said in the study.

The discovery was made using the Canada France Hawaii Telescope (CFHT), which combed the sky around Saturn between 2019 to 2021 and discovered an initial 62 additional moons in its orbit. The team also found faint signals of an even larger number of orbiting bodies but were unable to confirm them at the time.

"With the knowledge that these were probably moons, and that there were likely even more waiting to be discovered, we revisited the same sky fields for three consecutive months in 2023," Ashton said. "Sure enough, we found 128 new moons. Based on our projections, I don't think Jupiter will ever catch up."

The researchers say they are now finished moon-spotting for the foreseeable future, at least until telescopes capable of spotting even fainter signatures are developed.

"With current technology I don't think we can do much better than what has already been done for moons around Saturn, Uranus and Neptune," Ashton said.

A stunning photo has captured all seven of our neighboring planets in Earth's sky at the same time, possibly for the first time ever.

The composite image, captured by astrophotographer Josh Dury, shows Mars, Jupiter, Uranus, Saturn, Venus, Neptune and Mercury in alignment thanks to a rare "planetary parade" taking place this weekend for the first time since 1982. (Here's how you can see it for yourself tonight).

While spacecraft, such as NASA's Voyager 1, have snapped all the planets in the sky from space, terrestrial cameras have only recently become advanced enough to capture them from the ground — meaning Dury's photo is likely the very first of its kind.

"Seven (arguably, 8) is a feat that to my prior knowledge has not been achieved before," Dury told Live Science in an email — suggesting that if we include Earth itself, visible in the foreground, the image's planet total comes to eight. "This image could hold a record for being the first of its kind to photograph all the planets of the solar system, blended into a stitched panoramic image."

Dury captured the image just after sundown on Feb. 22 from The Mendip Hills — a range of limestone hills in Somerset in the U.K.

Related: Have all 8 planets ever aligned?

To achieve this photographic feat, Dury created a composite shot made up of several panes, with each pane captured in multiple exposures.

To locate Saturn, Neptune and Mercury, which were dimmer and closer to the western horizon, Dury used astronomy software to generate models of the night sky and match planetary locations to nearby star fields. He then used a high dynamic range (HDR) camera setting to capture the planets' faint light.

"I noted that when I took the image that it would not, of course, be possible to photograph the lowest planets at the moment of sunset — glare from the sun rendering this task impossible," Dury said. "Therefore, this image is a record of the first possible glimpse of the planets as light from the sun diminished." The night-sky models enabled him to later identify the planets in the image.

Planetary conjunctions occur when two or more planets appear to be close together in the sky. Of course, this is only from our perspective of the cosmos on Earth — in reality the planets remain extremely far apart.

These conjunctions aren't rare, but they get rarer with each planet added to the chain. For example, the three innermost planets — Mercury, Venus and Earth — align within 3.6 degrees in the sky every 39.6 years. For all of the solar system's eight planets to align as closely, it would take 396 billion years, something that has never happened and won't happen before the sun becomes a red giant, consuming Mercury, Venus and likely Earth in the process.

However, it is a little less unusual for all seven planets to appear spread out on the same side of the sun, as they do in Dury's image and in the night sky right now. Another seven-planet parade is expected to be visible from Earth in 2040.

If you'd like to see a planetary alignment for yourself, tonight (Feb. 28) is one of the best times to look. Time and Date and Stellarium are two great online tools for finding viewing times based on your location.

Seven planets in the solar system — Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune — will line up in the night sky Friday (Feb. 28) in an incredibly rare "planetary parade."

Although most of these planets have been visible in the night sky since January, Mercury will be joining the procession for just a few days, before Saturn gets lost in the sunset's glare in early March.

Five of these worlds will be easily visible to the unaided eye, but you will need a good telescope to see the full show, according to NASA.

That's because at least two of the planets — Uranus and Neptune — will be too dim to see with the naked eye and will likely be masked by the glare of the setting sun at twilight, NASA said. Saturn will also be trickier to see in some locations due to its position close to the horizon.

If you have a good telescope to catch the full display, the best time to view all seven planets in the Northern Hemisphere will be after sunset on Friday (Feb. 28) at around 8:30 p.m. local time, according to SkyatNightMagazine.

Related: Have all 8 planets ever aligned?

Planetary conjunctions occur when two or more planets appear to be close together in the sky. Of course, this is only from our perspective on Earth; in reality, the planets remain extremely far apart.

Conjunctions happen because the planets of the solar system orbit the sun along roughly the same flat plane as Earth, and they occasionally align when their different orbital distances and speeds bring them into a cluster on Earth's nightside.

These conjunctions aren't rare, but they do get rarer with each planet added to the chain. The three innermost planets — Mercury, Venus and Earth — align within 3.6 degrees in the sky every 39.6 years. For all of the solar system's eight planets to align that closely, it would take 396 billion years — something that has never happened and won't happen before the sun becomes a red giant, consuming Mercury, Venus and likely Earth in the process.

We recommend Time and Date and Stellarium as two great online tools for finding viewing dates and times based on where you are in the world. On mobile phones, Sky Tonight is a free app that will do the same job.

A striking new "planetary parade" photo combines images of six solar system worlds alongside the moon, providing a rare opportunity to compare the sizes of these celestial objects as they currently appear from Earth.

French astrophotographer Gwenaël Blanck created the stunning image by combining individual shots of each of the objects captured Feb. 2 from Paris, where he also took an exceptional photo of Venus and the moon aligning above the Eiffel Tower a day earlier.

The individual images were captured between 6:30 p.m. and 7:50 p.m. local time, using a digital camera attached to a telescope. Blanck then made a composite image of the six worlds in a straight line for the final photo. The objects are arranged from closest to Earth (left) to farthest from our planet (right): the moon, Venus, Mars, Jupiter, Saturn, Uranus and Neptune.

"I had to start quite early, shortly after sunset, to image Venus and Saturn before they were too low on the horizon," Blanck told Live Science in an email. "Neptune was also not far away [from the horizon]," he added. "It was probably the most difficult to capture."

"The Moon, Uranus, Jupiter and Mars were easier to capture, as they were higher in the sky," Blanck said. "The only missing planet was Mercury, which will become visible towards the end of the month and early March."

Related: Have all 8 planets ever aligned?

In reality, the objects in the image were scattered across the night sky. However, Blanck used the same magnification settings for each image, meaning the objects' sizes are perfectly scaled. That is why the moon looks so massive compared with Uranus and Neptune and why Venus and Jupiter appear to be around the same size, despite the latter being more than 10 times wider than the former.

"This gives a pretty good idea of the apparent size of each planet," Blanck said.

Planetary parade

We are currently in the midst of one of the most impressive planetary alignment events in recent years. Under the right circumstances, five planets — Mercury, Venus, Mars, Jupiter and Saturn — will be visible to the naked eye over the next few weeks. Uranus and Neptune are also present in the night sky, but you'll need a good telescope to see them alongside their brighter neighbors.

The event has already delivered some special moments, including an earlier alignment of six of the seven planets in late January and an occultation of Mars by the moon on Feb. 9. However, the parade will not peak until late February and early March, when all seven planets will align in a near-straight line along the horizon, according to Live Science's sister site Space.com.

Venus will be the brightest planet in the night sky during this period; it will be closest to the moon in the sky, making it easy to spot on most clear nights. The "love planet" will reach its peak brightness in time for Valentine's Day (Feb. 14).

If you want to see the best of the planetary parade for yourself, we recommend using a decent telescope or a pair of stargazing binoculars.

The next time we will see a similar alignment of the planets will be in October 2028.

What it is: Saturn's largest moon, Titan

Where it is: Approximately 750 million miles (1.2 billion kilometers) from Earth

When it was shared: May 4, 2006

Why it's so special: This picture was taken by the European Space Agency's Huygens probe during its historic parachute descent onto Titan's surface on Jan. 14, 2005. At the moment this image was captured, the probe was approximately 3 miles (5 km) above Saturn's largest moon. The probe's descent from its parent spacecraft, NASA's Cassini, took approximately 2.5 hours. When Huygens landed with a thud near the bright equatorial region of Adiri, it made history as the first and only probe to land in the outer solar system. The probe carried instruments to study Titan's smog-like atmosphere, chemical properties, wind, temperature and pressure. It was also equipped with cameras to capture Titan's surface.

Although the probe itself was not designed to withstand the landing, it not only survived but also returned images of frigid Titan's surface for another hour and 10 minutes after touchdown, until its batteries died.

Over the years, images collected by Huygens' Descent Imager/Spectral Radiometer instrument revealed that Titan's surface has Earth-like features including narrow drainage canals, dry lake beds, islands and shoals. Two more instruments — the Gas Chromatograph and Mass Spectrometer and the Surface Science Package — provided compelling evidence for the presence of methane rain and liquid flowing on Titan. Although the rivers and lakes appeared dry when Huygens touched down, evidence suggested that liquid methane may have flowed across the moon's surface not long ago.

The Huygens landing was part of the Cassini mission, which launched on Oct. 15, 1997. In 2017, after 20 years of thrilling exploration, the spacecraft made its final approach to Saturn, plunged into its atmosphere, and burned up, dramatically ending its remarkable journey.

Get your binoculars out! On Saturday (Jan. 4), skywatchers in the U.K. and most of Western and Central Europe will be able to see Saturn vanish behind the crescent moon — an event known as a lunar occultation. There are only two lunar occultations of Saturn in 2025, so you won't want to miss this stunning event.

To get the best viewing experience, choose a location that's away from artificial light and allow about half an hour for your eyes to adjust to the dark.

Saturn is very bright, so you can easily view it with your naked eyes. However, it's best to use a pair of good binoculars or a backyard telescope so you can see Saturn as it grazes the edge of the moon. Binoculars or a telescope will allow you to see the moon's craters in sharp relief, and you'll even be able to spot Saturn's rings and moons.

On Jan. 4, the moon will be a waxing crescent, about 19% illuminated. The moon and Saturn will be close together all night, so they will rise and set around the same time. The rise and set times will vary slightly depending on your location. You can use apps like Stellarium or sites like Time and Date to see when the moon and the planets will rise and set in your exact location.

Saturn will vanish behind the unilluminated part of the moon around 5:15 p.m. GMT, and will emerge from behind the illuminated part of the moon around 6:30 p.m. GMT. However, these times will vary depending on your precise location. You can enter your location in the sidebar on In-the-Sky, which will tell you a more precise time.

The lunar occultation of Saturn will be visible throughout the U.K. and most of Western and Central Europe, as well as in parts of Northern Europe and Northern Africa. This map shows the countries where this lunar occultation will be visible.

Although the lunar occultation of Saturn won't be visible across the globe, you will still be able to see the conjunction of the moon and Saturn if you miss the lunar occultation. Look for Saturn and the moon in the southwestern sky. The moon will be about 30 degrees above the horizon.

The next lunar occultation will be in February; it will be visible from extreme northern latitudes, parts of Russia and eastern Asia. After that, the next easily visible lunar occultation of Saturn will be in 2037.

Another spectacular year for stargazers lies ahead. From the appearance of a brilliantly bright Venus to the first total lunar eclipse since 2022, there will be plenty of reasons to look skywards at night this year. Other highlights will include a deep partial solar eclipse in North America, four moonless meteor showers and three supermoons. While many of these events will be visible to the naked eye, investing now in a good beginner telescope can greatly enhance your experience.

Quadrantid meteor shower

When: Jan. 3/4, 2025

The Quadrantid meteor shower, the first meteor shower of the year for the Northern Hemisphere, can often impress — if you can stand the cold — with between 25 and 200 shooting stars per hour during its peak. It's also the last meteor shower until April's Lyrids.

Venus at its brightest

When: Feb. 19, 2025

As Venus reaches its closest point to Earth, it will shine at -4.5 magnitude — as bright as it ever gets — but the dazzling sight will reveal something else if you point a small telescope at it. As an inner planet, when it nears Earth, it appears as a crescent; watch from Jan. 11 to Feb. 19, and you'll see it shrink each night.

Total lunar eclipse

When: March 13 to 14, 2025

The first total eclipse of the moon since late 2022 will turn the lunar surface a gorgeous orangey-reddish color for 65 minutes. North America will get a ringside seat, with the event seen throughout the continent during the night. Europe isn't so lucky, as it will get just a glimpse of the phenomenon during moonset.

Northern lights at equinox

When: March 20 and Sept. 22, 2025

The equinoxes, when Earth's axis is tilted neither toward nor away from the sun, create the ideal geometry for reliable and spectacular displays of auroras around the poles — and this year, these light shows will likely occur farther north and south. With the sun at solar maximum in 2025, expect increased solar activity, including aurora-triggering outbursts, particularly in the few weeks after the equinoxes.

Partial solar eclipse

When: March 29, 2025

Although it won't match the total solar eclipse of April 8, 2024, for sheer drama, those in northeastern U.S. states and eastern provinces in Canada may glimpse an eclipsed sunrise if skies are clear. This partial solar eclipse will see as much as 94% of the sun blocked by the moon, and it will also occur across Europe and northwest Africa.

Lyrid meteor shower

When: April 21 to 22, 2025

With 2024's Perseids — the most prolific and popular meteor shower of the year — marred by bright moonlight, other meteor showers will have to pick up the slack. With a crescent moon setting early in the evening, expect a good show from the Lyrids, which deliver about 10 to 20 shooting stars per hour and a few super-bright fireballs. April is also a good month to begin looking for the Milky Way later at night.

Eta Aquariid meteor shower

When: May 6 to 7, 2025

Expect about 60 shooting stars per hour during the peak of the Eta Aquariids, which will take place under ideal astronomical conditions. It is one of two meteor showers caused by dust and debris left in the inner solar system by Halley's comet (the other being November Orionids). The Eta Aquariids are best seen from the Southern Hemisphere.

Saturn at opposition

When: Sept. 21, 2025

Saturn will be at its brightest and best in late September as Earth passes between the gas giant and the sun. This will be the best time to see Saturn, though you'll need a small telescope to see its rings. There will be no opposition from Jupiter in 2025 — the giant planet will align with Earth and the sun early in 2026.

Venus and Jupiter conjunction

When: Aug. 12, 2025

Get up before sunrise on this date, and you'll likely see the beautiful sight of Jupiter and Venus shining just a degree from each other. That's less than the width of your little finger held out at arm's length against the sky. Jupiter will shine at -1.8 magnitude and Venus at -3.9 magnitude.

Beaver supermoon

When: Nov. 5, 2025

There will be three supermoons in 2025, the closest of which will be November's Beaver Moon at 221,726 miles (356,833 kilometers) from Earth. It will be the closest full moon this year and the closest since 2019. It will be preceded by October's Hunter's Moon and December's Cold Moon, with January 2026's Wolf Moon also being a supermoon.

Of all the planets in our solar system, Saturn is by far the mooniest. And that's saying a lot. Sure, we're here in our corner with our single friend, The Moon™, but Neptune wanders the universe with 16 known companions, Uranus boasts 28 of its own, and there are a whopping 95 moons in the Jovian neighborhood. But Saturn? It's in a different league. This ringed world has 146 of these natural satellites. Yet, you may be surprised to know that even with such a lovely Saturnian selection, scientists are mostly pining over just one.

The golden child in Saturn's system is named Enceladus, and it's so special because scientists believe it to be a prime location to search for life beyond Earth. That belief stems from several discoveries made over the years, most obviously the fact that Enceladus seems to have a subsurface ocean that may host molecules known to help produce life as we know it. Better yet, it also appears to have giant plumes of water ice deposits (think icy geysers shooting into space) connected to that ocean, which means spacecraft orbiting the world could theoretically catch evidence of those molecules if they're actually there.

Thus, when studying Enceladus, every detail really matters — which brings us to a new, very strange detail that scientists have their eye on: A weird, disappearing dark spot on this ice-capped moon. No one quite knows what it is yet, but it may tell us something about those plumes that could hold the precious building blocks of life we seek.

This dark spot was one of the intriguing topics of discussion during the 2024 American Geophysical Union meeting in Washington, D.C. — where scientists congregated to search for the final pieces in cosmic puzzles they've been working on all year.

Awe filled the room as Cynthia B. Phillips, a planetary geologist at NASA's Jet Propulsion Laboratory who presented the research, went into tremendous detail about how she and her team originally identified the dark spot. It was thanks to her crewmember Leah Sacks, who helped pore through a bulk of data about Enceladus, collected by NASA's Voyager and Cassini missions. The goal of the analysis was to compare images of the same region taken by these spacecraft in order to identify any changes on the moon's surface.

Possible changes could reveal awesome information about geologic activity on the world, but we'll get to that shortly; first let's dive into the mysteries of the dark spot.

"After staring at dozens and dozens of image pairs — she found something interesting," Phillips said during the conference. "It's a little dark spot; it's about a kilometer across. She spotted it in an image from 2009 and looked again in 2012 and it seemed to be gone."

The dark spot was slowly fading away and getting smaller as the years progressed, and it never became more pronounced again. How weird, and especially so because Enceladus has what's called a high "albedo." That basically means the world is really bright — it's therefore unexpected to find a dark spot on it at all, let alone one that's fading away. But before getting too excited, the scientists made sure to second guess themselves as much as possible to rule out the obvious caveats.

"First our question was," Phillips said, "'well, is it just that in some of these low resolution images, we're not seeing it, but it's really there?'" In short, the answer was a simple "no, probably not." For example, a direct comparison of a 2010 image and a 2011 image shows the dark spot smaller in the 2011 image, even though the 2011 image had a higher resolution.

The next question was: Is this a shadow of some sort? Well, nope. Doesn't look like it.

The team pulled out some images with lighting coming from different directions, and the location of the spot seemed consistent. The researchers even found a sequence of images with the dark spot where the light's angle of incidence (aka, the angle at which light strikes a surface) gets higher and higher. If the spot were a shadow, you'd expect it to become more prominent with a higher incidence angle. This wasn't the case — it still became less distinct as time went on. "We don't think it's topography; we don't think it's just a shadow," Phillips told Space.com.

And it didn't end here — the team also looked at images taken in UV light and color (the latter of which interestingly suggested that the dark spot is a reddish brown, unlike the usual blueish darker areas on other sections of the moon). None of this suggested an easy explanation for the feature.

So, what is it?

"I think the more likely [case] is that it is some kind of a crater," Phillips told Space.com. "And the reason why it's dark is maybe it's a chunk of some kind of dark material that landed on the surface, and you're either seeing some of that impactor left behind, and that's why it has that weird color, or you're seeing that when it impacted, it exposed some kind of bedrock of ice that was a different color."

But for almost every likely and mundane scenario in space research, there tends to exist a rare and exciting one serving as a counterpoint.

"The really cool explanation would be if it was actually coming up from underneath, somehow; if that reddish color was actually a sign of the interior composition of Enceladus," she said. "That's unlikely, but that'd be really interesting."

Still, although we don't know what the dark spot is, Phillips points out that there is indeed something pretty major we can derive from its presence: "'What is it?' I don't know the answer to that — but what I can say is: 'What can we use it for?'"

Remember the plumes

In a nutshell, the researchers think the dark spot appeared to be fading progressively because deposits from those icy Enceladus plumes might have covered it up. "We know the whole surface is covered by plume deposits — like little layers of ice building up over time," Phillips said.

Alas, in theory, this makes a lot of sense. But when you really think about it, there are some outstanding issues here.

For example, the team saw the dark spot fading over just a few years — this would imply that just a few years is long enough for ice plume deposits to create a sheet of ice thick enough to cover such a prominent spot. After all, it's visible from space! Yet, according to various calculations of the dark spot and models of the moon's plumes, Phillips says it should take something like 100 years to create a layer thick enough to cover this kind of spot.

"What this could mean, though, is that the plume deposition model, at least in this location, is an underestimate," she said. "One thing we haven't taken into account, though, is deposition from collisions with E ring particles."

E ring particles refer to the super small water ice particles in Saturn's rings. Potentially, the team reasons, some of those particles could be helping build the sheet covering the dark spot. But the story of this spot's origin and evolution, at this point, is mirrored by the abrupt ending of our story of its discovery.

There are simply too many unanswered questions.

"What would the deposition rate needed to cover the black spot in this time frame indicate about deposition rates? Is the E ring contributing to cover that spot? Is there maybe another mechanism?" Phillips pondered.

"And, you know, what is the black spot?"

Originally posted on Space.com.

Saturn's rings could be billions of years old despite not looking a day over a few hundred million, a new study has found.

The rings of Saturn are one of our solar system's greatest wonders; made up of billions, if not trillions, of chunks of water ice which can be smaller than a grain of sand and larger than a mountain, according to NASA. However, they're also a bit of an enigma.

Researchers have been debating the origins and age of Saturn's rings for decades. Some scientists argue that the rings formed as recently as 100 million years ago — when dinosaurs still roamed our planet — after Saturn's gravitational pull tore apart a passing comet or icy moon.

One of the reasons scientists believed the rings were so young is that they appear very clean — in the context of planetary rings, this means that the icy chunks from which they are formed haven't been dirtied up by collisions with tiny space rocks called micrometeoroids over billions of years. However, a new study published Dec. 16 in the journal Nature Geoscience suggests that micrometeoroids wouldn't actually stick to the rings, so they may look younger than they really are.

"A clean appearance does not necessarily mean the rings are young," study lead author Ryuki Hyodo, a planetary scientist at the Institute of Science Tokyo, told Live Science's sister site Space.com.

Related: Saturn's moon Titan may have a 6-mile-thick crust of methane ice — could life be under there?

The new study suggests that the rings could have formed early in the solar system's history, around 4.5 billion to 4 billion years ago, when, according to Hyodo, the solar system was a lot more chaotic.

"Many large planetary bodies were still migrating and interacting, greatly increasing the chances of a significant event that could have led to the formation of Saturn's rings," he said.

To learn more about the rings, Hyodo's team used computer modeling to run simulations of micrometeoroid strikes. These simulations determined that the micrometeoroids would hit the rings at a high enough speed to be vaporized, reaching a peak temperature of almost 18,000 degrees Fahrenheit (10,000 degrees Celsius), according to the study. In other words, no solid material would be implanted in the rings.

Additional simulations suggested that vapor from the micrometeoroids would expand, cool and then form charged nanoparticles and ions, which would collide with Saturn, escape its gravity or get dragged into the planet's atmosphere. Either way, the rings would be left squeaky clean and retain a relatively youthful appearance.

However, the debate over the age of the rings is likely to continue. Sascha Kempf, an associate professor of physics at the University of Colorado Boulder who led a 2023 study suggesting that Saturn's rings are no older than 400 million years old, isn't convinced by the new findings.

Kempf told the New Scientist that his team used a more complex method for estimating ages that relied on more than just ring pollution efficiency and included the time it takes for material to arrive and disappear.

"We are pretty certain that this is not really telling us that we have to go back to the drawing board," Kempf said.

Lotfi Ben-Jaffel, a researcher at the Paris Institute of Astrophysics in France who wasn't involved in either study, told New Scientist that the new research suggests the rings are older than has been claimed in recent years but added that Hyodo's team still needs to improve their modeling to give a more precise age estimate.

"It represents a positive step toward the missing modeling effort required to properly handle the fundamental problem of the formation and evolution of a planetary ring system," Ben-Jaffel said.

Scientists have discovered that the icy shell of Saturn's largest moon, Titan, could possess an insulated, six-mile-thick (9.7-kilometer-thick) layer of methane ice beneath its surface. Ironically, this layer may make signs of life from the subsurface ocean of Titan easier to detect. And, down the line, the discovery could benefit the fight against human-driven climate change on Earth.

Titan may be a moon, but it is also more similar to Earth than any other solar system planet. That's because it is the only planet or moon in the solar system other than Earth to possess an atmosphere as well as liquid rivers, lakes and seas. Because of the frigid temperatures of Titan, however, this liquid is composed of hydrocarbons like methane and ethane. Still, the surface ice of Titan is indeed composed of water.

The new results from a team of planetary scientists at the University of Hawaii at Mānoa revealed that methane gas may also be trapped within Titan's ice shell, forming a distinct crust up to six miles thick. This gas could warm the underlying ice shell and help molecules rise to the surface of Titan, some of which could indicate the presence of life. This warming may also help explain Titan’s methane-rich atmosphere.

"If life exists in Titan's ocean under the thick ice shell, any signs of life, biomarkers, would need to be transported up Titan's ice shell to where we could more easily access or view them with future missions," research team leader and University of Hawaii scientist Lauren Schurmeier said in a statement. "This is more likely to occur if Titan’s ice shell is warm and connecting."

The team was first tipped off to the potential existence of this connecting layer of methane ice by the presence of shallow impact craters on Titan. Only 90 impact craters have been seen on the surface of the Saturnian moon, and these have been confusing to observe because they should be hundreds of feet deeper than they actually are.

"This was very surprising because, based on other moons, we expect to see many more impact craters on the surface and craters that are much deeper than what we observe on Titan," Schurmeier said. "We realized something unique to Titan must be making them become shallower and disappear relatively quickly."

Investigating Titan's shallow craters

To further delve into the mystery of Titans' swallow impact craters, Schurmeier and colleagues turned to computer modeling. This allowed them to test how much the surface of Saturn's largest moon would relax and rebound after an asteroid impact if its icy shell were coated with an insulating layer of methane clathrate.

Related: Mysterious 'magic' islands that come and go on Saturn's moon Titan finally have an explanation

Methane clathrate, or "methane hydrate," is a solid compound in which a large amount of methane is trapped within the crystalline structure of water, creating a solid similar to ice.

Considering craters of similar size on an icy moon of Jupiter that's comparable to Titan, Ganymede, the researchers could compare possible depths of impact craters on the Saturnian moon.

"Using this modeling approach, we were able to constrain the methane clathrate crust thickness to five to 10 kilometers [about three to six miles] because simulations using that thickness produced crater depths that best matched the observed craters," added Schurmeier. "The methane clathrate crust warms Titan's interior and causes surprisingly rapid topographic relaxation, which results in crater shallowing at a rate that is close to that of fast-moving warm glaciers on Earth."

The thickness of this methane icy shell matters because it could eventually explain why Titan's atmosphere is particularly rich with this hydrocarbon. It could also help scientists better understand Titan's carbon cycle, its liquid methane-based "hydrological cycle," and the changing climate of the Saturnian moon.

"Titan is a natural laboratory to study how the greenhouse gas methane warms and cycles through the atmosphere," Schurmeier explained. "Earth's methane clathrate hydrates, found in the permafrost of Siberia and below the arctic seafloor, are currently destabilizing and releasing methane.

"So, lessons from Titan can provide important insights into processes happening on Earth."

The thickness of the methane clathrate crust, when viewed in the light of the topography of Titan, means that the Saturnian moon's interior is likely warm and flexible rather than cold and rigid, as once believed.

"Methane clathrate is stronger and more insulating than regular water ice," Schurmeier added. "A clathrate crust insulates Titan's interior, makes the water ice shell very warm and ductile, and implies that Titan's ice shell is or was slowly convecting."

And that convection means that biomarkers indicating life could have been hoisted from Titan's subsurface ocean and carried to its outer icy shell, just awaiting discovery.

This research could act as a helpful guide to NASA scientists who intend to investigate Titan using the forthcoming Dragonfly spacecraft. Dragonfly is set to launch in 2028 and hopefully reach the Saturnian system in 2034 to conduct up-close observations of Titan's icy surface.

The team's research was published on Sept. 30 in The Planetary Science Journal.

Originally posted on Space.com.

On Oct. 14, NASA's Europa Clipper mission launched from Kennedy Space Center in Florida toward one of Jupiter's largest moons. The launch was eagerly anticipated by scientists around the world, in part because Europa, with its plumes of liquid water and icy crust, is thought to be one of the best places in the solar system to search for life beyond Earth.

But Europa isn't Jupiter's only moon — far from it. Officially, Jupiter has 101 moons recognized by the International Astronomical Union. But the question of how many natural satellites the planet truly has is a bit more complicated.

Jupiter's four best-known moons are the Galilean moons, discovered by Galileo Galilei in 1610. They are named Ganymede, Callisto, Io and Europa, after figures in Greek mythology associated with the god Zeus. ("Jupiter" is the ancient Roman name for Zeus.) These moons are big — each is roughly the size of Earth's moon or larger, and together, they make up around 99.97% of the mass of all the material orbiting the gas giant. Due to their size and the presence of geologic processes like volcanism, these moons produce and maintain their own thin atmospheres.

Related: NASA reveals 'glass-smooth lake of cooling lava' on surface of Jupiter's moon Io

Each of Jupiter's other nearly 100 official moons has a diameter greater than 0.6 mile (1 kilometer) — but only 57 have names, and just eight have regular, nearly round orbits. However, they are "generally too small to hold onto any [atmospheric] vapor," Statia Cook, an astronomer at New York University, told Live Science in an email.

In addition to Jupiter's certified moons, thousands of smaller "moonlets" — most of which are captured asteroids and chunks of debris — circle the planet.

Jupiter isn't the only planet in the solar system with myriad moons. For decades, it has vied with its neighboring gas giant Saturn over which has the most natural satellites.

How many moons does Saturn have?

Saturn's eight largest moons were discovered between 1671 and 1848 by several astronomers. For much of the 20th century, the moon counts for Jupiter and Saturn remained relatively stable at 12 and eight, respectively. But in 1979, NASA's Voyager probes uncovered two previously unknown Jovian moons and added three moons to Saturn's repertoire.

These discoveries hinted that both planets might have more in their orbits, kicking off more than 40 years of moon hunting. Between 2018 and 2023, the leader flip-flopped several times. For now, though, Saturn holds the title for the most moons, with a whopping 146.

Saturn's biggest moon by far is Titan, with almost twice the mass of Earth's moon. "Titan is really special — it has clouds and rain, rivers and lakes — but made of hydrocarbons like methane instead of water," Cook said. Currently, it's one of the best candidates for extraterrestrial life in the solar system, alongside Europa.

Future research will tell whether moons like Titan and Europa harbor the necessary ingredients for life. Europa Clipper will begin investigating its moon in 2030, and NASA's Dragonfly probe is scheduled to launch in 2028 and arrive at Titan in 2034. They represent "an exciting step forward in our mission to investigate whether the conditions for life could exist beyond Earth, right here in our own solar system," Cook said.

In the coming weeks, NASA will launch a hotly anticipated new mission to Jupiter's fourth-largest moon, Europa.

Called Europa Clipper, the spacecraft will conduct a detailed study of the moon, looking for potential places where Europa might host alien life. (The launch window for the mission begins Oct. 10, but the launch has been temporarily postponed due to the impending landfall of Hurricane Milton.)

Europa Clipper is the largest planetary exploration spacecraft NASA has ever made: as wide as a basketball court when its solar sails are unfolded. It has a mass of about 6,000 kilograms — the weight of a large African elephant.

But why are we sending a hulking spacecraft all the way to Europa?

Looking for life away from Earth

The search for life in places other than Earth usually focuses on our neighbour Mars, a planet that's technically in the "habitable zone" of our Solar System. But Mars is not an attractive place to live, due to its lack of atmosphere and high levels of radiation. However, it's close to Earth, making it relatively easy to send missions to explore it.

But there are other places in the Solar System that could support life — some of the moons of Jupiter and Saturn. Why? They have liquid water.

Here on Earth, water is the solvent of life: water dissolves salts and sugars, and facilitates the chemical reactions needed for life on Earth to proceed. It's possible life forms exist elsewhere that rely on liquid methane or carbon dioxide or something else, but life as we know it uses water.

The reason there's liquid water so far out in the Solar System is because Jupiter and Saturn, the gas giants, wield immense gravitational power over their moons.

Saturn's moons, Titan and Enceladus, are stretched and compressed by gravity as they go around their host planet. This movement results in vast underground oceans with a surface of solid ice, with plumes of water vapour exploding 9,600 kilometres from the surface.

It is strongly suspected that Europa is the same. While we know a lot about Europa from more than four centuries of observation, we have not confirmed it has an under-ice liquid ocean like Titan and Enceladus.

Related: Jupiter's moon Europa lacks oxygen, making it less hospitable for sustaining life

But all clues point to yes. Europa has a smooth surface despite being hit by many meteors, suggesting the surface is young, recently replaced. Ice volcanoes raining down water over the surface would make sense.

It also has a magnetic field, suggesting that like Earth, Europa has a liquid layer inside (on Earth, this liquid is molten rock).

What will Europa Clipper do?

At the surface, Europa is bombarded by high levels of space radiation, concentrated by Jupiter. But deeper down, the thick ice sheet could be protecting life in the liquid subsurface ocean.

This means it would be difficult for us to find concrete evidence for life without drilling down deep. But where to look? Through flybys of the icy moon, Europa Clipper will be looking at areas where life could be dwelling under the icy shell.

To achieve this, Europa Clipper has nine scientific instruments. These include a wide-angle camera to study geologic activity and a thermal imaging system to measure surface texture and detect warmer regions on the surface.

There's also a spectrometer for looking at the chemical composition of the gases and surface of Europa, and for any explosive plumes of water from the surface. The mission also has tools for mapping the moon's surface.

Other instruments will measure the depth and salt levels of the moon's ocean and the thickness of its ice shell, and also how Europa flexes within the strong gravitational pull of Jupiter.

Excitingly, a mass spectrometer will analyze the gases of the moon's faint atmosphere and potential plumes of water. By examining the material ejected from the plumes, we can understand what is hidden within the under-ice oceans of Europa.

A dust analyser will also look at matter that has been ejected from Europa's surface by tiny meteorites or released from the plumes.

Unfortunately, we will have to wait a while for any discoveries. Europa Clipper will take more than five years to reach Jupiter. And the mission is only equipped to look for the potential of life, not life itself. If we see evidence that might point towards life, we will need future missions to return and explore Europa in depth.

So we must be patient. But this is an exciting opportunity for humanity to get one step closer to find life beyond our own home planet.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Earth may have had a giant ring of space rocks surrounding it, similar to those around Saturn, which could have led to chaotic meteorite strikes on our planet's surface, new research suggests.

The hypothesized ring may have formed roughly 466 million years ago and was the remains of a gigantic asteroid tugged apart by Earth's tidal forces after passing our planet's Roche limit.

Casting a shadow across Earth's equator, the ring may have contributed to a global cooling event by blocking sunlight, while bombarding the surface with meteorites. The researchers published their findings Sept. 16 in the journal Earth and Planetary Science Letters.

"Over millions of years, material from this ring gradually fell to Earth, creating the spike in meteorite impacts observed in the geological record," study lead author Andy Tomkins, a professor of planetary science at Monash University in Australia, said in a statement. "We also see that layers in sedimentary rocks from this period contain extraordinary amounts of meteorite debris."

The scientists arrived at the startling hypothesis by studying a period in Earth's history known as the Ordovician (485 million to 443 million years ago). The Ordovician was a tumultuous time for our planet — it was one of the coldest periods in the last 500 million years and saw a dramatic uptick in the rate of meteorites striking Earth.

Related: Could scientists stop a 'planet killer' asteroid from hitting Earth?

To investigate what could have caused these effects, the scientists mapped the positions of 21 Ordovician asteroid impact craters, which revealed that all the impacts occurred within 30 degrees of Earth's equator.

As 70% of Earth's continental crust was located outside this region, the researchers calculated that the probability of this happening by chance was the same as tossing a three-sided die 21 times and getting the same outcome 21 times.

With these highly unlikely odds in mind, the researchers settled on a hypothesis that could explain both the equatorial strikes and planet's cooling — a ring, the remnants of a smashed-up asteroid, encircling Earth at the equator.

More evidence is needed to support the hypothesis, but the ancient ring theory could explain many aspects of Earth's history, especially if rings appeared more than once above our planet before being slowly erased as their asteroids were sucked down by its gravity, the researchers said.

"The idea that a ring system could have influenced global temperatures adds a new layer of complexity to our understanding of how extra-terrestrial events may have shaped Earth's climate," Tomkins said.

The best time to view Saturn is rapidly approaching!

The best view of the ringed planet occurs when it enters opposition — in other words, when the Earth is directly between Saturn and the sun. This year, that's overnight between Sept. 7 and Sept. 8.

You do not want to miss this once-a-year opportunity to see Saturn at its biggest and brightest; after Sept. 8, 2024, you won't be able to see Saturn in opposition until Sept. 21, 2025. Here's everything you need to know to spot Saturn at its peak size and brightness.

How to view Saturn

Viewing Saturn with the naked eye isn't optimal because you won't be able to see its stunning rings. (Without gear, the planet looks like a very bright star). The best way to view Saturn is to use a backyard telescope, or a strong pair of stargazing binoculars, so you can see Saturn's rings in sharp relief.

Because Saturn is nearing opposition, it will be in the opposite part of the sky as the setting Sun. On Sept. 7 and 8, Saturn will appear in the constellation Aquarius. You can use sky charts that are updated daily to see Saturn's current position relative to Aquarius, or if you'd like a little more hands-on help with finding the ringed planet, you can use apps like Stellarium to easily locate Saturn or other celestial objects.

Related: The best meteor showers of 2024 are yet to come. Here are the key nights to watch for.

When to see Saturn

Saturn will rise between approximately 6 p.m. and 7 p.m. local time on Sept. 7 and will set between approximately 5:30 a.m. and 6:30 a.m. local time on Sept. 8. Saturn will reach its highest point in the sky around midnight local time on Sept. 8. (You can use this tool from the U.S. Navy to check precise rise and set times in your exact location).

Saturn will reach opposition when Saturn and the sun are positioned directly opposite of each other in the sky; this will happen at 12:27 a.m. EDT on Sept. 8. When Saturn reaches opposition, it will appear larger because it will be at its closest point to Earth.

n the night of Sept. 7-8, the moon will be a waxing crescent (18% full) and will set around 10 p.m. local time, creating perfect observing conditions.

If you don't get the chance to observe the night sky on Sept. 7-8, don't worry! Saturn will still appear bigger and brighter than usual in the week or so before and after it reaches opposition, so there's plenty of time to see Saturn's rings in all their glory. From the beginning of September to Sept. 13, the moon will set before midnight, which means that you'll have ample opportunity to see Saturn at or near opposition with moonlight-free skies.

The Seeliger Effect

When you observe Saturn as it nears opposition, you'll be able to see the Seeliger Effect, which is an unusual brightening of Saturn and its rings. This effect happens because of the position of Saturn relative to the sun and our position on the Earth: the sun casts its rays from behind Earth directly onto Saturn, directly illuminating Saturn and its rings, which is why Saturn is at its brightest when it's in opposition.

Stargazers enjoying the splendor of August's "Sturgeon Moon" — which is also a blue supermoon — on Aug. 20 may have noticed something peculiar: a planet disappearing from the sky.

In the wee hours of the morning, the moon occulted — or completely passed in front of — the bright planet Saturn, appearing to snuff the ringed world's light for more than an hour. The rare lunar occultation of Saturn was visible only from parts of South America, Europe and Africa. But if you missed it, don't worry — astrophotographer Josh Dury managed to capture the entire event from his perch in Somerset, England.

Taken between roughly 4 and 5:30 a.m. local time (11:00 p.m. to 12:30 a.m. EDT), Dury's image combines 30 individual shots into a single epic time lapse that charts the full course of the lunar occultation. Saturn's rings are clearly visible as the planet slides behind the northwestern limb of the full moon, reappearing in the east about an hour later. Although the two objects appear to share the same patch of sky, Saturn is in fact hundreds of millions of miles farther away, making the occultation a cosmic optical illusion similar to a solar eclipse.

The moon appears especially large and bright right now because it's a supermoon — a full moon orbiting within 90% of its closest point to Earth, also called perigee. At perigee, the moon can appear about 15% bigger in diameter than it does at its farthest point from Earth (apogee) and can look noticeably brighter as well, according to NASA. August's full moon is the first of four consecutive supermoons, giving skywatchers plenty of chances to appreciate our lunar companion this fall. Make sure you have a pair of stargazing binoculars or a good small telescope to get the most out of the moon's upcoming close-ups.

Related: The 10 best stargazing events of 2024

If you missed the occultation of Saturn this week, you may have a chance to spot the next one in September, depending on where you live. In the early hours of Sept. 17, the moon will again appear to gobble up the ringed planet. This time, viewers in parts of Australia and the western United States will have the best view, according to In-the-Sky.org.

This has been a busy month for stargazers, with vibrant auroras, a planetary conjunction and the Perseid meteor shower all lighting up the night sky. Just one week ago, Dury trekked to the astronomically appropriate site of Stonehenge to capture dozens of "shooting stars" falling over the ancient monument, where he took another gorgeous composite image of the dazzling sky show.

There are still plenty of skywatching events to come in 2024, including some of the year's best meteor showers. So get out, look up and enjoy.

Get your stargazing binoculars out! Overnight from Aug. 20 to 21, the blue supermoon will pass in front of — or occult — the ringed planet Saturn. Although Saturn and the moon will be low in the sky when the occultation starts, they will be easily visible when the event ends. After Saturn emerges from behind the moon, the large planet will stay close to the moon all night.

Here's everything you need to know to see this stunning event.

How to watch

Viewing Saturn with the naked eye isn't ideal; if you don't use a good backyard telescope or pair of binoculars, Saturn will be indistinguishable from any bright stars in the sky. The best way to view Saturn is to use a pair of high-powered binoculars or a telescope so that you can see its signature rings and moons. If you use a telescope, you can see Saturn in even more detail: in addition to seeing its rings and moons, you will be able to see the bands of clouds at its surface as well.

On Aug. 20, Saturn and the moon will rise in the southeastern part of the sky and set in the southwestern part of the sky. Saturn will lie in the constellation Aquarius, but since Saturn will be so close to the moon, you probably won't need to use Aquarius as a waypoint.

Related: Rare 'moonbows' light up night sky across US as blue supermoon rises — and you could still spot another one

When to watch

Saturn and the moon will rise around 9 p.m. local time on Aug. 20, and will set around 8 a.m. local time on the 21st. Depending on your vantage point, they will reach their highest point in the sky between approximately 2 and 3 a.m., reaching a height of about 42 degrees above the horizon, according to theskylive.com.

The moon will pass in front of Saturn around 8:44 p.m. local time. Depending on your exact location, the occultation will occur immediately before or immediately after the two objects cross the horizon.

If you miss the moment when the moon starts to occult Saturn, you may be able to see Saturn emerge from behind the moon, which will happen around 12:38 a.m. local time, when the moon is highest in the sky.

You can use apps like Stellarium to check on the precise times in your specific location.

Observing conditions

On the night of Aug. 20-21, the moon will be bright and full. Normally, dark skies are the most ideal for observing because moonlight can wash out other objects in the sky. However, Saturn is quite bright, so it will still be clearly visible despite the full moon.

The occultation of Saturn might not be visible to all observers because the apparent position of Saturn and other celestial objects can vary up to two degrees depending on your position on Earth. (This apparent shift in an object's position depending on your vantage point is called parallax). However, even if you just miss the occultation, you will still be able to see Saturn make an extremely close approach to the moon the entire night.

Low-temperature hydrothermal vents could survive on the dark ocean floors of moons like Jupiter's Europa for potentially billions of years, new computer simulations have shown, as astrobiologists strive to figure out whether these alien oceans could be habitable.

Hydrothermal vents are both a source of chemical energy and heat, and are one of the possible locations for the origin of life on Earth. Planetary scientists have theorized that hydrothermal vents at the bottom of the oceans beneath the ice on moons of Jupiter like Europa and Ganymede, and the Saturn satellite Enceladus, could help warm those oceans and kickstart the biochemistry of life.

The problem is that modeling of these vents has focused on the extremely high-temperature ones — the "black smokers" powered by volcanic activity. While these super-hot vents can siphon energy from Earth's hot core, the icy moons do not have hot cores, meaning there's been a question mark over whether such vents could survive long enough to create the long-term conditions for life. 

However, super-hot vents are not the dominant form of venting in Earth's oceans. On Earth, a much larger volume of water passes through lower-temperature vents.

"The flow of water through low-temperature venting is equivalent, in terms of the amount of water being discharged, to all the rivers and streams on Earth, and is responsible for about a quarter of Earth's heat loss," said Andrew Fisher of the University of California, Santa Cruz (UCSC), in a statement. "The entire volume of the ocean is pumped in and out of the seafloor about every half-million years."

Fisher led a team from UCSC that modeled the proliferation of such low-temperature vents on Europa and Enceladus. Given the absence of data about the oceans on these moons, Fisher's team based their simulations on the circulation system in the northwestern Pacific Ocean, specifically the eastern flank of the Juan de Fuca Ridge, where cool seawater sinks and flows down into the rock in the seabed via extinct volcanic cavities called seamounts. The water travels through the rock for about 30 miles (50 kilometers), being heated in the process, before rising up through another seamount. 

"The water gathers heat as it flows and comes out warmer than when it flowed in, and with very different chemistry," said study team member Kristin Dickerson, also of UCSC.

Related: 'Space potato' spotted by NASA Mars satellite is actually something much cooler

Applying this circulation model to Europa and Enceladus, the researchers altered properties such as gravity, temperature, the composition of the bedrock and how deep the water circulates, to better fit potential conditions on the ocean moons. 

They found that not only could moderately warm vents be maintained over a wide range of conditions on these moons, but that the low gravity allowed for warmer temperatures emanating from the vents. In addition, the low efficiency of heat extraction from the core of the moons (which are thought to be pretty cool in the first place) in the low gravity would allow such moderate- to low-temperature vents to be maintained for possibly billions of years.

"This study suggests that low-temperature — not too hot for life — hydrothermal systems could have been sustained on ocean worlds beyond Earth over timescales comparable to that required for life to take hold on Earth," said Fisher.

The research was published on June 24 in the Journal of Geophysical Research: Planets.

Originally posted on Space.com.

Like a lightbulb switching between high- and low-power modes, Saturn pumps into space varying amounts of heat based on its seasons, a fresh analysis of data from NASA's Cassini spacecraft reveals. 

A noticeable effect of this flux is turbulence in Saturn's atmosphere, which whips up storms across its north and south hemispheres strong enough to wrap around the planet, scientists report in a paper published Tuesday (June 18) in the journal Nature Communications. 

Such seasonal changes in radiated heat from Saturn and other gas giants are yet to be included in models describing their climates and evolutions, which assume the planets emit heat evenly in all directions and at a steady rate, Liming Li, a physics professor at the University of Houston, who a decade ago found Saturn does not emit energy evenly and is a co-author of the new study, previously told Space.com. 

"We believe our discovery of this seasonal energy imbalance necessitates a reevaluation of those models and theories," Xinyue Wang of the University of Houston in Texas, who led the new study, said in a recent statement.

Astronomers have long known that Saturn returns to space double the energy it soaks up from the sun. The extra energy comes from deep within Saturn, where heat left over from its birth pushes temperatures to about 15,000 degrees Fahrenheit (8,300 degrees Celsiuss) — hotter than the surface of the sun. Much of this internal heat is a byproduct of the planet slowly compressing due to its gravity, and some may arise from friction sparked by lots of helium sinking toward the planet's core.

Related: Uranus and Neptune aren't made of what we thought, new study hints

When NASA's Cassini spacecraft arrived at Saturn in 2004, the gas giant was in the middle of a southern summer with its south pole pointed toward the sun, while its northern hemisphere was blanketed in the darkness of winter. Equal amounts of sunlight warmed both halves of the planet in 2009, when the equinox arrived. Cassini witnessed three seasons play out in Saturn's northern hemisphere before the probe's intentional death plunge into the gas giant's atmosphere in September 2017: spring, summer and winter, each of which lasts about seven Earth years. 

While previous research led by Li had shown that the heat radiated by Saturn matched its seasons, the new study finds those periodic changes to also be due to changing amounts of sunlight absorbed as the gas giant swings widely between the closest and farthest points in its egg-shaped, 30-year-long orbit around the sun. 

"Not only does this give us new insight into the formation and evolution of planets, but it also changes the way we should think about planetary and atmospheric science," Li said in the statement.

Originally posted on Space.com.

A rare and stunning photo recently captured a "parade of planets," in which six planets in our solar system appeared together in the predawn sky.

The image shows Mercury, Mars, Jupiter, Saturn, Uranus and Neptune in alignment. Mars and Saturn are clearly visible near a crescent moon, while the positions of the remaining planets, which were too distant to be seen with the naked eye, were revealed by two composite long exposures. 

Astrophotographer Josh Dury captured the planetary parade on June 1 in the early hours of the morning from The Mendip Hills — a range of limestone hills in the county of Somerset in the U.K. on June 1. 

The annotated image shows Mars and Saturn clearly visible near a crescent moon, while the positions of the remaining planets (too distant to be seen with the naked eye but faintly visible in the image) were revealed by two composite long exposures.

"I thought no better than to climb Crooks Peak at the unearthly hour of 2am," Dury told Live Science via email. "As time passed, it was a really special experience. Being able to see one planet after another rising and being present in my images was fantastic and really encapsulated a sense of perspective of our place within the solar system, let alone the universe."

Related: Have all 8 planets ever aligned?

Planetary conjunctions occur when two or more planets appear to be close together in the sky. Of course, this is only from our perspective of the cosmos on Earth — in reality the planets remain extremely far apart.

These conjunctions aren't rare, but they do get rarer with each planet added to the chain. The three innermost planets  — Mercury, Venus and Earth — align within 3.6 degrees in the sky every 39.6 years. For all of the solar system's eight planets to align as closely, it would take 396 billion years — something that has never happened and won't happen before the sun becomes a red giant, consuming Mercury, Venus and likely Earth in the process, Live Science previously reported. 

If you'd like to see a planetary alignment for yourself, Time and Date and Stellarium are two great online tools for finding viewing dates and times based on where you are in the world.

Six of the planets in our solar system — Mercury, Mars, Jupiter, Saturn, Uranus and Neptune — are about to align on June 3 in what some media outlets are dubbing a "parade of planets." The sight is predicted to be best visible an hour before sunrise on June 3 and June 4.

But, despite a flurry of breathless coverage promising otherwise, you won't be able to see all six planets as they rise before dawn. What you can see depends on a variety of factors, including how early you wake up, how much light pollution you have to contend with, and whether you've got a pair of stargazing binoculars or a good small telescope to aid you. 

With that in mind, up to four of the planets on display (Mercury, Jupiter, Uranus and Neptune) may either be too dim to see with the naked eye or masked by the glare of the rising sun, skywatching journalist Jamie Carter wrote for Forbes. 

The remaining planets — Mars and Saturn — will be visible, though they will likely  appear dim in the predawn hours, when the alignment is predicted to occur, Carter added. (Mars and Saturn have actually been visible just before dawn all month long, rising steadily higher each morning in May, Earthsky.com notes.)

Related: Have all 8 planets ever aligned?

However, in a recent video from the National Science Foundation, astrophysicist Joe Pesce paints a more optimistic picture of the alignment.

"It's likely that we'll be able to see Mercury, certainly Jupiter, Mars and Saturn," Pesce said. "Uranus and Neptune are also involved, but you'd need binoculars or a telescope to be able to see those two planets."

Pesce added that the alignment will be visible for a few days before and after June 3, also. And if you don't have a great view of this particular planetary parade, "there's another event in late August, and several predicted for 2025," Pesce said.

All of this means that it may be risky to get up at the crack of dawn to see the upcoming parade of planets, with as many as four of the six planets involved possibly obscured in some way. Take your local weather conditions and light pollution into account before making your plans.

For those who do sacrifice their sleep to catch a glimpse of the alignment, you won’t be entirely let down. That's because on the nights in question, a beautiful crescent moon will be visible near Mars and Saturn, Carter notes.

If you're curious about this alignment, or other upcoming ones, Time and Date and Stellarium are two great online tools for finding viewing dates and times based on where you are in the world, and will even show you the locations of the four hidden planets on June 3. On mobile phones, the Sky Tonight is a free app that will do the same job.

Editor's note: This article was updated on May 31 to include new predictions from the National Science Foundation.

New research has revealed the sliding side-by-side motion along distinctive "tiger stripes" on Saturn's moon Enceladus is linked to jets of ice crystals that erupt from its icy shell. The findings could help determine the characteristics of this icy moon of Saturn's subsurface ocean and, thus, if Enceladus is favorable to life.

The tiger stripes of Enceladus consist of four parallel line fractures in the moon's south pole that were first observed by NASA's Cassini spacecraft in 2005. "Cryovolcanism" in this region blasts out ice crystals believed to originate from Enceladus' buried ocean from these fractures, causing a broad plume of material to gather over the south pole of the Saturnian moon.

Both the brightness of this plume and the jets that create it seem to vary in a pattern that lines up with the near 33-hour orbit of Enceladus around Saturn, the solar system's second most massive planet. This has led scientists to theorize that the activity of the jets increases as tidal stress acts upon the tiger stripes. 

However, this theory can't explain why the jets of Enceladus peak in brightness hours after tidal stresses are at their maximum or why there is a second smaller peak seen shortly after Enceladus' closest approach to Saturn. A new numerical simulation of Enceladus' tidal stresses and the motion of its tiger stripe fractures identifies a phenomenon similar to that seen at the San Andreas fault, corresponding with the pattern of jet activity.  

RELATED: NASA finds key ingredient for life gushing out of Saturn's icy moon Enceladus

"We developed a sophisticated numerical model to simulate tidally-driven strike-slip motion along Enceladus' faults. These models consider the role of friction, which causes the amount of slip on the faults to be sensitive to both compressional and shearing stresses," Alexander Berne, leader of the team behind the simulation and a PhD Candidate at the California Institute of Technology (Caltech), told Space.com. 

"The numerical model was able to simulate slip along Enceladus's faults in a manner which matched observed variations in plume brightness as well as spatial variations in surface temperature, suggesting that the jets and plume brightness variations are controlled by strike-slip motion over Enceladus' orbit."

The San Andreas fault in space

Berne and colleagues found that frictional mechanics control motion in interfaces along the tiger stripes of Enceladus where both sides of the fractures meet. This means that during Enceladus's orbital cycle, the tiger strips periodically slide and lock. This side-by-side, or "strike-slip," motion lines up with jet activity. 

The correlation between strike-slip activity and jet brightness in the simulation led the team to hypothesize that variations in jet activity are controlled by the presence of 'pull-aparts' along the faults. These are bent sections of the fractures that open under broad strike-slip motion, allowing water to rise from the subsurface ocean through the icy shell to feed the cryovolcanic jets. 

"A close terrestrial analogy is motion along pull-apart basin structures over large strike-slip faults subject to tectonic stresses. One example of such motion occurs over the Salton Basin – a large pull-apart located on the San Andreas fault, a strike-slip fault, in Southern California," Berne said. "Regional strike-slip motion causes localized crustal extension as well as volcanism over the Salton Basin. This process is similar to tidally-driven extension along pull-aparts at Enceladus, which may regulate the moon's cryovolcanic activity.

"Prior to conducting the research, we did not expect such a high correlation between modeled strike-slip motion and jet activity."

The team's research suggests that the tiger stripes of Enceladus open differently than previously modeled. 

"This finding was surprising since most past studies on the subject invoke broad opening along the tiger stripes, like opening and closing like an elevator door, as the primary mechanism regulating plume brightness variations," Berne said. 

The Caltech researcher added that the team's models suggest that tides play a fundamental role in the evolution of Enceladus and its ocean on multiple timescales. 

"On the orbital timescale, tides appear to regulate the amount of material flowing from a subsurface ocean through the tiger stripe fractures," Berne said. "At longer timescales, tides may cause frictional tiger stripes to fracture in a net right-lateral sense."

He continued by suggesting that this long-term right lateral motion may drive the formation of geologic features observed around the terrain of the southern pole of Enceladus. This includes a fracture that radiates away from the South Pole on the trailing Hemisphere of Enceladus. 

Scientists have suggested that Enceladus, with its buried global ocean, could be a prime target for searching for life elsewhere in the solar system. This research and the team's model could provide extra support for that hypothesis. 

"Understanding subsurface material transport pathways through pull-apart or broad rift zones is crucial for determining whether ice grains in Enceladus' jets are representative of the moon's potentially habitable global ocean. Our study provides a framework for understanding such transport pathways and their evolution over time," Berne said. 

"Evidence for the long-term influence of tides on the evolution of Enceladus, which also heat the interior, implies that the moon's ocean is long-lived, which has implications for the potential evolution of life in the interior."

At the moment, the team's conclusion is based upon a computer simulation and thus needs to be confirmed with actual observations.

"Geophysical measurements at Enceladus using radar would allow us to confirm or refute the hypotheses laid out in our paper. More broadly, such observations of the movement of Enceladus' surface over time can provide key constraints on the dynamics of the core and the crust, as well as the extent to which these processes have been active over time," Berne concluded. "We aim to continue to investigate ways we can use geophysical measurements to better understand the conditions which may enable life to form and evolve on Enceladus."

The team's research was published on Monday (April 29) in the journal Nature Geoscience.

Originally posted on Space.com.

The James Webb Space Telescope (JWST) is set to begin investigating the spectacular light shows of solar system giants Uranus and Saturn.

Two separate teams of astronomers at the University of Leicester will use the $10-billion space telescope to study auroras over the gas giant Saturn and the frigid ice giant Uranus. The aim will be to explain in greater detail the processes that create these polar light shows over different planets.

"The JWST is already changing how we perceive the universe, from the solar system, our very own cosmic backyard, to the first galaxies formed at the beginning of time," Henrik Melin from the University of Leicester School of Physics and Astronomy who will lead the Uranus investigation, said in a statement. "I am thrilled to have been awarded time on this remarkable observatory, and this data will fundamentally shape our understanding of both Saturn and Uranus.”

Auroras are familiar to skywatchers over Earth as the stunning Northern Lights and Southern Lights, which can be seen along the poles of our planet when they appear.

Related: Astronomers spot aurora on the sun for the 1st time

These light shows are generated over Earth when charged particles that stream from the sun's solar wind strike our planet's protective magnetic field, known as the magnetosphere. These particles travel down magnetic field lines and stream out behind Earth — but, as they do this, they interact with particles in our atmosphere, creating glowing light.

When the sun blasts out high volumes of stellar plasma in so-called coronal mass ejections, auroras are more prominent and can be seen at lower latitudes over Earth.

Though auroras have been seen over other solar system planets before, and they should be possible around any planet with an atmosphere and magnetic field, less is known about these alien light shows.

Currently, relatively little is known about the auroras of Uranus, an ice giant with an atmosphere of water, ammonia and methane.

It was actually only last year, after three decades of investigation, that a research team from the University of Leicester School of Physics and Astronomy — led by Ph.D. student Emma Thomas — confirmed an infrared aurora around Uranus.

Because of a past impact with a roughly Earth-sized body, Uranus is tilted at a 97.77-degree angle. This means that its poles are orientated almost directly toward and away from the sun, and its auroras are positioned around what would normally be the equator for a solar system planet.

As Melin and his colleagues use the JWST to observe the auroras of Uranus, which is the seventh planet from the sun, they will investigate something suggested by this previous discovery of Uranian auroras: Are the auroras of this distant planet responsible for keeping it warmer than expected?

"The temperature of all the gas giant planets, including Uranus, are hundreds of degrees Kelvin/Celsius above what models predict if only warmed by the sun, leaving us with the big question of how these planets are so much hotter than expected," Thomas said last year. "One theory suggests the energetic aurora is the cause of this, which generates and pushes heat from the aurora down towards the magnetic equator."

The JWST study of Uranus will begin early in 2025; it will capture images of the ice giant over a single day for the planet, which lasts around 17 Earth hours. This should allow the team to map auroral emissions across a whole rotation of Uranus' magnetic field.

The scientists will also aim to discover if emissions are produced when the Uranian magnetic field interacts with the solar wind, as happens over the Earth, or if interacting charged particles come from sources within the system similar to how Jupiter creates its auroras. There is also the possibility that Uranus' auroras are created as a combination of these phenomena, just as Saturn's auroras seem to be generated.

The JWST Saturn aurora project, led by Boston University Center for Space Physics scientist Luke Moore, will observe the gas giant's northern auroral region for an entire 10.6-hour Saturnian day. This will allow the team to monitor how the temperature of this region changes as the gas giant rotates.

By revealing Saturn's atmospheric auroral energies for the first time, the team hopes to learn more about the sources of charged particles within the gas giant's atmosphere that drive its auroras.

Both JWST giant planet studies will be conducted using the powerful space telescope's highly sensitive Near-Infrared Camera (NIRCam) instrument.

Once these findings are in hand, scientists can better understand the processes that create auroras in the solar system and the role these mechanisms have on Earth in particular. Perhaps the results can help astronomers glean information about auroras around planet beyond the system too: Extrasolar planets, or "exoplanets."

“A majority of exoplanets discovered so far fall in the sub-Neptune category and hence are physically similar to Neptune and Uranus in size. This may also mean similar magnetic and atmospheric characteristics too," Thomas said. "By analyzing Uranus's aurora, which directly connects to both the planet's magnetic field and atmosphere, we can make predictions about the atmospheres and magnetic fields of these worlds and hence their suitability for life."

Originally posted on Space.com.

Spacecraft flying through ice plumes in space could help scientists spot alien life — even if it's only tiny bits of a cell in a few grains of ice, lab experiments have revealed for the first time.

If alien life resides on Saturn's moon Enceladus or Jupiter's Europa, enormous geysers blasting out of the moons and into space are currently the most accessible way to find evidence of it. As recent studies of Enceladus have shown, these powerful plumes originate from each moon's vast subsurface ocean and spew out into space via cracks in their icy shells, ferrying ice grains that scientists think could be infused with bacterial cells and other organic molecules. Spacecraft flying through these plumes can then identify signs of life that may be encrusted in the ice, the new research shows.

"It's just astonishing how well we can identify a bacterial cell in these grains," Fabian Klenner, a researcher at the University of Washington in Seattle and lead author of the new study, told Live Science. "Even if there is only a tiny fraction in a handful of grains, we can find it with these instruments."

By sampling and analyzing plumes of Enceladus and perhaps Europa, scientists can learn whether life-friendly molecules exist in their subsurface oceans. But of the hundreds of thousands of ice grains blasted into space by these icy moons, bacterial cells may be concentrated only in a tiny number of them.

Related: NASA unveils cryptic message from Earth to be sent to Jupiter's icy ocean moon Europa

Cells on ice

To simulate such a scenario in a lab, Klenner and his team mixed cells of freeze-dried bacteria named Sphingopyxis alaskensis in liquid water such that there was one bacteria cell in every droplet, on average. Commonly seen in Alaskan sea waters, S. alaskensis lives in cold environments and can survive on low nutrients, "which makes it a better analog than many other organisms that we know from Earth," Klenner told Live Science. 

"They are extremely small, so they are in theory capable of fitting into ice grains that are emitted from an ocean world like Enceladus or Europa," he said in a statement.

In the experiment, described in a study published Friday (March 22) in the journal Science Advances, the researchers used a very thin tube to inject this water into a small vacuum chamber. The water droplets were 15 micrometers in diameter, "which is a bit bigger than the ice grains in space but it is still extremely tiny," Klenner told Live Science.

A laser beam then charged up the water droplets and the bacteria within. Using mass spectroscopy — a technique that spacecraft are capable of performing — researchers gathered the particles' spectra, a measure of different wavelengths of light emitted by the particles, which can reveal their compositions. They found plenty of amino acids and fatty acids, among other signs that clearly pointed to a bacterial cell, which they knew was already in the water sample.

The results show even if just 1% of a cell is encrusted onto a tiny ice grain, its chemical signature will be apparent.

"Our results give us more confidence that using upcoming instruments, we will be able to detect lifeforms similar to those on Earth, which we increasingly believe could be present on ocean-bearing moons," Klenner said in the statement.

On a mission lasting three to four years, for instance, spacecraft can sample hundreds of thousands of grains, if not billions, across multiple flybys of a target. Even if a few of those grains revealed a spectra similar to what the researchers found, then the "chances would be not too bad that this is a bacterial cell or fragment of a cell," Klenner told Live Science. "The cool thing is you only need to find a cell in, let's say, a handful of these grains, and these instruments can tell you if there is a bacterial cell."

The dust analyzer on board NASA's Cassini spacecraft, which in 2005 discovered the plumes venting from Saturn's moon Enceladus, could record only 30 to 300 particles in each flyby. So the probe "was definitely not capable of finding bacterial cells if they were there," Klenner told Live Science.

Another NASA mission named Europa Clipper, which is scheduled to lift off this October on a journey to study Jupiter's icy moon Europa, can sample 10,000 to 100,000 individual ice grains during each flyby, raising the chances of detecting bacterial cells, if they exist on the moon.

Using such instruments, "it might be easier than we thought to find life, or traces of it, on icy moons," study co-author Frank Postberg, a professor of planetary sciences at the Free University of Berlin, said in the statement. "If life is present there, of course, and cares to be enclosed in ice grains originating from an environment such as a subsurface water reservoir."

Astronomers have discovered that a tiny moon of Saturn, named Mimas, may harbor a hidden liquid ocean beneath its thick icy shell and may thus have the conditions for habitability.

This shocking finding radically changes the definition of what an ocean moon can be, and could ultimately redefine our search for alien life on moons in the solar system. That's because, at first appearance, Mimas — nicknamed the 'Death Star' because a large crater means it resembles the Empire's space station in Star Wars — doesn't look like the kind of body scientists would expect to support an ocean. In fact, it doesn't even look capable of supporting such a vast body of liquid at all.

The team behind the watery discovery estimates the ocean is located around 12 to 18 miles (20 to 30 kilometers) beneath the ice crust surface of Mimas; the researchers also believe it is relatively young, having only appeared between 2 million and 25 million years ago. Yet, despite remaining hidden for millions of years, the ocean appears to comprise at least half of the moon's volume.

"The major finding here is the discovery of habitability conditions on a solar system object which we would never, never expect to have liquid water," Valery Lainey, discovery team member and a scientist at the Observatoire de Paris, told Space.com. "It's really astonishing."

The discovery makes Mimas even more similar to its Saturnian moon sibling, Enceladus, which scientists had already known has a subsurface ocean. Both moons exist at similar distances from the gas giant planet and are similar in size, with the ice-covered Enceladus measuring around 310 miles (500 kilometers) across and the similarly frigid Mimas sitting slightly smaller at 246 miles (396 km) across.

One key difference between the two moons is that, whereas the ocean of Enceladus breaches its surface in the form of massive jets and plumes, the sea of Mimas has yet to crack its icy crust.

That means that, while NASA's Cassini spacecraft was able to fly through plumes of ice spraying from Enceladus to confirm its oceans and even discover some of the complex molecules contained within, the spacecraft was not able to do any such thing for Mimas.

"It's really surprising we haven't seen anything, but the thickness of the icy shell of Mimas is enough to maintain this ocean without any significant activity betraying it for millions of years," Lainey continued. "That's why Cassini did not find anything at the surface of Mimas."

However, that doesn't mean Cassini, which spent 13 years in Saturn's system before purposefully crashing into the gas giant in 2017, wasn't key in assisting in the discovery of the ocean of Mimas.

Mimas' 'wobble'

Lainey and colleagues discovered their initial hints of Mimas having a buried liquid ocean when they used Cassini data to investigate a break in the infamous rings of Saturn called the "Cassini division."

In 2010, while aiming to discover if a change in Mimas' orbit could have caused the Cassini division, the team noticed a strange shift in both the moon's rotation and its orbit. The team determined, in 2014, that these large librations were either the result of the Saturnian moon having a misshapen, solid rocky core — or, a subsurface ocean that would allow its outer shell to oscillate independently of its core.

The breakthrough came when the team finally modeled the motion of Mimas, and determined a rocky core could only be responsible for the observations if it was elongated and flat like a pancake. Obviously, this did this not match what the team was seeing in real life, but moreover, the way Mimas' orbit has evolved since 2014 also offered support to the global subsurface ocean hypothesis.

"There is no rigid interior that can be compatible with the rotation and the orbital evolution of Mimas," Lainey said. "It is a relief to eventually succeed in demonstrating that that is the solution."

A waterlogged moon

Not only was the team able to determine that the oceans have only been present for a few million years (due to the fact that Mimas' orbit remains flattened, or eccentric) but the crew was also able to calculate just how much water is likely present in the moon's oceans.

"At least 50% of the volume of Mimas is filled by liquid water," Lainey said. "This is a huge amount of liquid water for the size of the satellite."

This water appears to be grinding against the rocky core of Mimas, simultaneously getting heated by the friction this action generates. This interaction also gives rise to what Lainey describes as "interesting chemistry" likely developing on the Saturnian moon — right now.

Water and rock interactions are thought to have played a vital role in the origins and continued existence of life on Earth, meaning such chemistry on Mimas is indeed an exciting prospect for investigations of life and habitability in the solar system.

"Mimas is a small object that looks extremely cold, with no geologic activity, and you would never expect any geophysical activity inside like heating, or contact between water and with silicates in its rocky core," Lainey said. "Finding this happening is really astonishing."

For future investigations, Lainey said he would love to land a spacecraft on the surface of Mimas, or even Enceladus for that matter.

"I'm pretty sure any space mission to Enceladus will also visit Mimas as they are extremely close, and they are extremely similar ocean systems but at different times in their evolution," he explained.

But with NASA's planned Orbilander set to leave Earth in 2038 and arrive at the latter moon in 2050, such a project is still a long, long time away.

In the meantime, Lainey intends to investigate Mimas from Earth to learn more about how its temperature has evolved, how the presence of this ocean has impacted the Saturnian moon's orbit, and what effect this has had on the rings of Saturn and the gas giant's other moons. This could help better calculate the age of Mimas' oceans.

"I would emphasize that Mimas definitely doesn't look like the sort of object that could have habitability," Lainey added. "So maybe the conclusion is that if this object can be habitable, who knows what other kinds of object may be habitable?"

The team's research was published on Wednesday (Feb. 7) in the journal Nature.

Originally posted on Space.com.

Saturn's moon Titan may be known for its methane lakes, but it also has "magic" islands — mysterious bright spots atop the lakes that come and go, with no known explanation. However, a new study, published Jan. 4 in the journal Geophysical Research Letters, proposes a surprisingly simple explanation for the magic islands: They're floating chunks of frozen organic material.

"I wanted to investigate whether the magic islands could actually be organics floating on the surface, like pumice that can float on water here on Earth before finally sinking," study  lead author Xinting Yu, a planetary scientist at the University of Texas at San Antonio, said in a statement.

Titan is a particularly strange place in the solar system, with a "methane cycle" somewhat analogous to the water cycle on Earth. Instead of liquid water oceans, it has placid liquid methane lakes, whose waves measure only a few millimeters. Instead of having an oxygen atmosphere, Titan is filled with hazy clouds of organic molecules.

Yu wondered what would happen if clumps of that atmospheric haze fell into the lakes. Would they float or sink — or perhaps even float for a while before eventually succumbing to the liquid, just like the magic islands?

"For us to see the magic islands, they can't just float for a second and then sink," Yu said. "They have to float for some time, but not for forever, either."

The researchers used physics and chemistry calculations to determine what happens to particles when they hit the lake, and, if they didn’t sink, how long they’d stay afloat. They found that the clumps of solids wouldn't dissolve in the lakes. But they would also be too heavy to float — that is, unless they were extremely porous, full of holes just like the pumice stones Yu imagined.

The researchers found that if the clumps were big enough and had enough holes, they would float until the methane slowly seeped in and dragged them down. These conditions replicated the behavior of the magic islands. To reach the critical mass needed to stay afloat, clumps might first form on the shoreline, with pieces breaking off and drifting to "sea" like glaciers on Earth, the team suggested.

It seems like the islands aren't so magical after all — just an unfamiliar version of the same planetary phenomena we know on our home world.

A spectacular year for stargazers is ahead. From the Quadrantid meteor shower in January to the opposition of Jupiter in December, there will be plenty of opportunities to witness the universe's wonders. Highlights of the year include a rare total solar eclipse seen from North America, a moonless Perseid meteor shower and two comets that will shine so bright they may be visible to the naked eye, making 2024 a year not to be missed for sky-watchers. While many of these events are visible with the naked eye, investing now in a good beginner telescope can greatly enhance your experience.

Here are some dates for this year's stargazing diary.

1. Quadrantid meteor shower

When: Jan. 3/4, 2024

The Quadrantids are overshadowed by December's Geminids, but they can produce 60 to 200 meteors per hour and include bright "fireballs," according to NASA. Here's everything you need to know about watching the Quadrantids peak.

2. March equinox

When: March 20, 2024

Although not a stargazing event per se, Earth's axis being tilted neither toward nor away from the sun can often create the ideal geometry for spectacular displays of auroras around the poles. Since the sun is predicted to hit solar maximum during 2024, resulting in increased solar activity including aurora-triggering outbursts, this equinox could see some special shows.

3. Total solar eclipse

When: April 8, 2024

One of nature's most spectacular sights is coming to North America. On April 8, for up to 4 minutes 28 seconds, a glimpse of the sun's corona amid darkness in the day is available to anyone who gets into the 115-mile-wide path of totality through parts of northern Mexico, 15 U.S. states and five Canadian provinces.

4. Comet Pons-Brooks

When: April 21, 2024

The coming year may be a good one for bright comets. The volcanic comet Pons-Brooks, which orbits the sun every 71 years, will be visible using binoculars during March and April, and on 12 April, it will be close to Jupiter. The comet will reach its brightest on 21 April, so that's the date to prioritize.

Related: Best binoculars for stargazing 2023: Spot stars and galaxies

5. Eta Aquariid meteor shower

When: May 6, 2024

One of two meteor showers caused by dust and debris left in the inner solar system by Halley's comet, the Eta Aquariids will in 2024 occur under moonless night skies, ensuring enough darkness to see its 10 to 20 "shooting stars" per hour.

6. Perseid meteor shower

When: Aug. 12/13, 2024

Often producing bright meteors easily visible to the naked eye, the Perseids meteor shower is one of the most famous of the year. The moon will be absent from the sky, so expect a good show — and great views of the Milky Way if you stay up until the skies get their darkest around midnight.

7. Saturn at opposition

When: Sept. 8, 2024

In early September, Saturn will be at its brightest and best as Earth passes between it and the sun. This will be the best time to see Saturn, though you'll need a small telescope to see its rings.

8. Comet Tsuchinshan-ATLAS

When: Oct. 13, 2024

Although it's expected to be visible in the sky before sunrise in late September, the best time to see Comet Tsuchinshan-ATLAS — only discovered in January 2023 -– is Oct. 13, as that's when it's likely to be its brightest.

9. Hunter's Supermoon

When: Oct. 17, 2024

A super-size moon will grace the skies on this date as the closest full moon to Earth rises. It's one of three supermoons of the year; the others will rise on Sept. 18 and Nov. 15, but this one will be the largest. Expect high tides in the supermoon's wake.

10. Jupiter at opposition

When: Dec. 7, 2024

On this date, the giant planet Jupiter will shine its brightest, its disk will be 100% lit by the sun, and it will rise at dusk and set at dawn. For telescope users, it’s a  great time to see the gas giant's Great Red Spot and four large moons. With the event occurring so close to Christmas, don't be surprised to see the planet compared to the "Star of Bethlehem."

Editor's note: This article was updated on Feb. 12 to correct an error about Saturn at oppostion.

Every year, we learn more about the intricacies of the solar system, and 2023 has been no different. This year, scientists shed more light on our cosmic neighborhood with some intriguing discoveries. From shrinking planets and new moons to an icy supervolcano and mysterious spots, here are the 10 wildest things we learned about the solar system in 2023. 

Mercury is shrinking 

Starting with the planet closest to the sun, Mercury, an October study revealed that the solar system's tiniest planet might be getting even smaller.

Experts have long known that Mercury has shrunk significantly since it first formed. Giant cracks, known as scarps, on the planet's surface were created as the planet contracted over long periods of cooling. 

Scientists originally thought these scarps were billions of years old, but the new research showed that some were just 300 million years old, which suggests the planet has been shrinking for most of its life — and it could still be happening today. 

This year, scientists also discovered that salty glaciers in some of Mercury's craters could provide the necessary conditions for some extreme life-forms to thrive.

Oxygen found on Venus 

Moving farther from the sun, researchers announced in November that oxygen had been detected in Venus' atmosphere for the second time, confirming that the element is present on the hellish planet. 

The thin layer of molecular oxygen (unbonded oxygen atoms) was spotted by NASA's Stratospheric Observatory for Infrared Astronomy, a telescope attached to a large plane that flew above most forms of interference in Earth's atmosphere between 2014 and 2022.

However, this oxygen is not a sign of life on Venus. Instead, researchers suspect the gas is created as solar radiation breaks down carbon dioxide and carbon monoxide molecules in the atmosphere. This oxygen would also be useless to future human colonists because it is not breathable and is found in low concentrations.

This year, scientists also discovered that Venus has thousands more volcanoes than we previously realized and that a majority of them could still be active.

The moon is older than we thought 

Closer to home, a study published in October revealed that the moon may be at least 40 million years older than we previously thought.

Researchers examined tiny impact crystals, known as zircon crystals, within lunar rock samples brought back by NASA's Apollo 17 mission. The new analysis revealed that these crystals,which were left by a colossal collision between Earth and a Mars-size planet that birthed the moon, were older than similar crystals found in other lunar samples.

"These crystals are the oldest known solids that formed after the giant impact," the researchers wrote, and they act as "an anchor for lunar chronology."

This year, astronomers also detected a mysterious heat-emitting blob on the moon's far side and spotted a separate chunk of the moon orbiting Earth.

Mars is spinning faster and faster

One of the biggest stories to come from Mars this year is that the Red Planet's spin has been getting quicker every year, and scientists don't know why.   

Data from NASA's InSight mission shows that Mars' rotation is accelerating at a rate of 4 milliarcseconds per year, which means its days are growing slightly shorter. (A milliarcsecond is one one-thousandth of an arcsecond, which is a unit of angularity.)

Two leading theories explain the speed-up. The first is that ice accumulation at the planet's poles is causing a slight change in how its mass is distributed, and the second is a phenomenon called postglacial rebound, where landmasses rise up after millennia buried under ice.

This year, scientists also solved the mystery of the planet's largest-ever "marsquake" and calculated the minimum number of people needed to start a Martian colony.

Jupiter has a dozen new moons 

This year, scientists confirmed the existence of 12 new moons around Jupiter, bringing the planet's satellite count to 92. At the time, this set a new solar system record.

The newly discovered Jovian moons are small, ranging from 0.6 to 2 miles (1 to 3.2 kilometers) wide, and most of them have wide orbits — nine of the 12 moons take more than 550 days to orbit Jupiter.

The moons were discovered in 2021 and 2022 but were just confirmed this year by the International Astronomical Union's Minor Planet Center.

This year, NASA's Juno spacecraft also discovered organic compounds on the surface of Jupiter's largest moon, Ganymede. The molecules likely came from the moon's subsurface ocean, hinting that it could sustain life.

But Saturn has even more moons

If you thought Jupiter gained lots of moons this year, just wait until you get a load of Saturn's new satellites. This year, scientists officially added 62 moons to the ringed planet's roster, bringing its total to 145 and setting a new record that is unlikely to be broken by Jupiter again. 

Some of the new moons were just 1.6 miles (2.5 km) wide. But all of the newly detected satellites are "irregular moons," meaning they follow distant, elliptical orbits around their host planet and often move in retrograde, meaning in the opposite direction of Saturn's rotation. Some are also clumped together, suggesting they were once a single body that broke apart.

This year, scientists also spotted a key organic compound shooting out of Saturn's icy ocean moon Enceladus, and researchers also worked out that the astronomer who discovered Saturn's largest moon, Titan, was probably nearsighted.  

Polar vortex spotted on Uranus 

Moving into the outer planets, new images of Uranus showed a gigantic "polar vortex" swirling around the ice giant's north pole, suggesting the planet's atmosphere is not as inert as we previously believed.

A polar vortex is a swirling ring of hot or cold air that circles a planet's polar region. These vortices have been spotted on Venus, Earth, Mars, Jupiter, Saturn and Neptune. And in 1986, NASA's Voyager 2 probe spotted a polar vortex around Uranus' south pole on its journey out of the solar system.

The swirling rings are thought to be caused by high-altitude atmospheric jet streams, although the mechanisms differ from planet to planet.

Earlier this year, scientists also spotted a polar vortex on the sun for the first time.

Neptune keeps growing mysterious spots 

This year, astronomers captured the first, clear image of one of Neptune's mysterious dark spots from Earth and photographed a never-before-seen bright spot at the same time.

Temporary dark spots have been documented on the solar system's most distant planet since 1989, when Voyager 2 spotted one as it passed by. Scientists think the dark spots are probably gigantic storms, like Jupiter's "Great Red Spot," but they are unsure why the spots appear so dark. 

The recent bright spot has never been seen before and lasted only a few weeks, so its origins are even more mysterious. But the different spots are likely linked, researchers said.

This year, astronomers also noticed that all of Neptune's clouds had suddenly vanished. The disappearing act is likely linked to a peak in solar activity as the sun reaches the explosive peak in its roughly 11-year solar cycle, known as the solar maximum. 

Pluto has an icy supervolcano 

Demoted planet Pluto has been hiding a gigantic cryovolcano the size of Yellowstone's supervolcano, an October study revealed.

Cryovolcanoes, also known as ice volcanoes, are simply volcanoes that erupt with cryomagma — ice, water and various gases — instead of molten rock. They've been found in several places across the solar system, including the dwarf planet Ceres and at the heart of explosive comets, such as the "devil comet."

Pluto's newly discovered volcano, named Kiladze Caldera, was originally pegged as a crater in images captured by NASA's New Horizons mission. But after taking a second look at the data, scientists detected traces of cryomagama around the depression, which is evidence that it has erupted multiple times.

Scientists don't know if it's still active, but if it is, it could produce enough cryomagma to cover Los Angeles.

Planet Nine might not exist (but it also might) 

Planet Nine is a hypothetical planet that is rumored to exist somewhere in the outer reaches of the solar system.

The Planet Nine hypothesis arose when astronomers detected gravitational anomalies in the Kuiper Belt — a group of comets and asteroids beyond the orbit of Neptune. These anomalies suggest that an invisible planet up to 10 times the size of Earth is lurking beyond the Kuiper Belt.

But in a preprint paper uploaded in September, scientists proposed that these gravitational anomalies could be explained by an alternative theory of gravity, known as modified Newtonian dynamics (MOND). 

MOND suggests that entities toward the edge of the Milky Way, such as the solar system, experience a greater gravitational tug from our galaxy's supermassive black hole heart than traditional gravity allows. Therefore, the Kuiper Belt object may be tugged away by our galaxy and not an elusive planet. However, MOND is not a universally accepted theory, so for now, our best guess is that Planet Nine does exist. 

Saturn's moon Enceladus has a secret lurking beneath its icy outer crust. In the plumes of vapor jetting from its surface, scientists have detected a molecule that might be a precursor for life: hydrogen cyanide.

On Earth, hydrogen cyanide is toxic to most organisms. But scientists believe it played an important role in the early origin of life, potentially serving as a precursor molecule in the evolution of amino acids — the building blocks of proteins required for life.

"It's the starting point for most theories on the origin of life, Jonah Peter, a biophysics researcher at Harvard University and lead author of a new study on the finding, said in an interview with the New York Times. "It's sort of the Swiss Army knife of prebiotic chemistry."

Enceladus has intrigued astrobiologists since 2005, when NASA's Cassini probe detected jets of gas and icy crystals erupting from cryovolcanoes near its south pole. These plumes suggest that the moon might be geologically active, and that a vast, salty ocean lies beneath its frozen exterior. Previous analysis of data taken from Cassini's multiple flybys revealed that this spray is full of organic molecules, such as methane, which hint at complex chemical activity happening in the subterranean sea.

Related: Astronomers find remnants of the oldest stars in the universe

Peter and his co-authors also used data from the Cassini mission in their new study, which was published in the journal Nature Astronomy on Dec. 14. Their results confirm that something is driving organic chemical reactions in Enceladus's ocean — and that it might be releasing more energy than previously thought. In addition to hydrogen cyanide, the researchers detected a cocktail of oxidized organic molecules, which wouldn't be possible to synthesize without significant energy input.

"If methanogenesis is like a small watch battery, in terms of energy, then our results suggest the ocean of Enceladus might offer something more akin to a car battery, capable of providing a large amount of energy to any life that might be present," Kevin Hand, an astrobiologist at NASA's Jet Propulsion Laboratory and co-author of the study, said in a statement.

While this by no means confirms the presence of life, it does strengthen the case for it on Enceladus. But the icy moon is far from the only candidate for life elsewhere in our solar system. Scientists are also eager to probe the oceans of Jupiter's moon, Europa, and another of Saturn's moons, Titan. They are also still scouring the surface of Mars, as well as the clouds drifting through Venus's upper atmosphere, looking for alien microbes that might be living there.

Whether or not one of these candidates yields extraterrestrial life, researchers can learn a lot more about how the chemistry and origins of life on our own planet emerged by studying these neighboring worlds.

When NASA's Cassini spacecraft turned its instruments to Saturn's moon Enceladus, it observed plumes of ice shooting up from the moon's surface at speeds of about 900 miles per hour (1,448 kilometers per hour). These geysers seemed to be the tendrils of a vast subsurface ocean — and made scientists curious if their fluid might carry life signs, organic molecules.

But if scientists want to study those organic molecules, they'll need to find a careful way of collecting them without destroying them. There is now good news on that front: If one lab experiment is correct, then any possible amino acids in those geysers' fluid are expected to easily survive contact with a spacecraft.

Researchers learned this in the lab by working with a physical apparatus designed to examine collisions. The researchers created ice particles by pushing water through a high-voltage needle; the charge fragmented the water into tiny droplets, each of which crystallized into an ice grain as it entered a vacuum. Then, the researchers shot the hardened grains through a spectrometer and imaged each grain as well as recorded impact times.

Related: James Webb telescope discovers gargantuan geyser on Saturn's moon, blasting water hundreds of miles into space

They found that amino acids within the ice grains could survive impact speeds up to 9,400 mph (15,128 kilometers per hour). That's more than enough to survive an encounter with a space probe.

To determine if ice contains fingerprints of life, scientists want to get undamaged ice grains so they can get a clear read on compounds that lie within the ice. "Our work shows that this is possible with the ice plumes of Enceladus," Robert Continetti, a chemist at the University of California San Diego and one of the researchers behind the work, said in a statement.

And while the experiment used data from Enceladus, it has consequences beyond one moon of Saturn. If similar amino acids exist on other water-bearing moons, like Jupiter's Europa, then missions like the future Europa Clipper might be able to find them in ice grains as well.

The researchers published their work on Dec. 4 in the journal Proceedings of the National Academy of Sciences.

Originally posted on Space.com.

When you're standing on Earth's surface, it's easy to forget that our planet is hurtling around the sun at more than 67,000 mph (107,800 km/h). And it's even easier to forget that there are seven other planets also making their way around our home star at similar breakneck speeds, or that all eight have been ceaselessly circling the solar system for billions of years. 

But what might really blow your mind is finding out how many trips around the sun each planet has under its belt. This may seem like a tricky thing to calculate, but because the planets' orbits have remained largely unaltered for most of their existence, all it takes is a bit of basic math.

Related: What's the maximum number of planets that could orbit the sun?

The solar system was born around 4.6 billion years ago, when the sun began to form from a cloud of dust left behind by prior stellar explosions. Around 4.59 billion years ago, the giant planets — Jupiter, Saturn, Uranus and Neptune — were born. And around 4.5 billion years ago, the smaller, rocky planets — Mercury, Venus, Earth and Mars — took shape, according to The Planetary Society.

But when the planets were born, their orbits around the sun were not the same as they are today (especially those of the giant planets). For around 100 million years after the first planets formed, there was a "dynamical instability" among them, which resulted in a gravitational tug-of-war between these large bodies and caused the rest of the outer solar system's planetary material, and even some emerging protoplanets, to be catapulted out of the solar system, Sean Raymond, an astronomer at the Bordeaux Astrophysics Laboratory in France and an expert on planetary systems, told Live Science in an email. 

However, once all of the planets had emerged and finished jostling with one another for their positions, they settled into consistent, stable orbits that haven't changed much since.

"For 98% to 99% of the solar system's lifetime, the planets' orbits have been nice and stable," Raymond said. As a result, you can use the planets' current orbital dynamics to make a pretty accurate guess at how many trips they have made around the sun, he added.

Take Earth, for example. Our planet takes a year to orbit the sun and has existed for 4.5 billion years, so it has taken roughly 4.5 billion trips around the solar system. 

However, the number of total orbits varies greatly among the other planets because their years are either shorter or longer than Earth's.

Mercury, the closest planet to the sun, takes only 88 days (or roughly 0.24 years, based on a year with 365.25 days) to travel around the sun once. So, over the past 4.5 billion years, it has completed around 18.7 billion solar orbits. But Neptune, the farthest planet from the sun, takes around 60,190 days (or 164.7 years) to complete an orbit, which means it has managed only about 27.9 million trips around the sun during its 4.59 billion years of existence. That means Mercury has orbited the sun around 18.7 billion times more than Neptune has.

Here is the full list of the planets, their year length and their total number of trips around the sun:

These sound like impressive numbers (and they are) but most of the planets could potentially double their number of orbits in their remaining lifetimes. 

In around 4.5 billion years, the sun will have swollen outward to reach Earth's orbit and transition into a red dwarf star, which will destroy Mercury, Venus and Earth. The other planets may live on for a time if they are not burned up but their orbits will likely be majorly altered.

What it is: Saturn, the seventh planet from the sun, as seen by NASA's Voyager 2 spacecraft

When it was taken: Aug. 11, 1981

Where it is: 886 million miles (1.4 billion kilometers) from the sun — 9.5 times the Earth-sun distance

Why it's so special: Taken 42 years ago this month, this false-color image from NASA's Voyager 2 probe shows the convective clouds and storms in Saturn's northern hemisphere. Visible on the right side of the image are the moons Dione and Enceladus, the latter of which recent observations from the James Webb Space Telescope show is spraying huge plumes of watery vapor far into space.

The image was taken 9 million miles (15 million km) from Earth, just as Voyager 2 approached the ringed planet, using the spacecraft's VG ISS Narrow Angle instrument. The false-color image was assembled from ultraviolet, violet and green images with filters used to make them visible to the human eye. If you look beneath the yellow band of clouds (which, in reality, would be white), you'll see a green spot (which is actually brown) that represents a storm. Voyager 2 measured winds blowing at Saturn's equator at a whopping 1,100 mph (1,770 km/h).

Voyager 2 wasn't the first probe to image Saturn. That distinction goes to Pioneer 11, one of NASA's first solar system probes, which launched in 1973 on a mission to study Jupiter, Saturn and the asteroid belt as a pathfinder for the Voyager missions.

Nor was Voyager 2 the first of the two Voyager probes to photograph the ringed planet. Its twin, Voyager 1, reached Saturn in November 1980, while Voyager 2 visited nine months later, making its closest approach on Aug. 26, 1981. However, because Voyager 2 had more sensitive cameras, it was able to detect a lot more features in Saturn's turbulent atmosphere, according to NASA.

How to see it in the night sky: Now is the perfect time to see Saturn, but to get any sense of its rings, you'll need a good telescope. The ringed planet is currently at its biggest, brightest and best for the year, having reached opposition (when Earth is between it and the sun) on Aug. 27. Saturn is currently in the constellation Aquarius and rising in the east at dusk.

Imagine a thunderstorm so massive that its dark outline wrapped around the entire planet. 

Such terrifying "megastorms" are common on Saturn. Also called "Great White Spots," they erupt once every 20 or 30 years in the planet's northern hemisphere and rage nonstop for months. Astronomers have spotted six of these planet-wide storms whipping around on Saturn since 1876. The most recent storm struck in December 2010, when NASA's Cassini spacecraft happened to be orbiting the planet, snagging a front-row view of the megastorm's entire 200-day life span. 

Now, new research into the epic 2010 storm has found that those 200 days of thunder were just a few drops in a much bigger, weirder meteorological bucket. According to recent radio telescope scans, the ongoing impacts of megastorms that erupted on Saturn more than 100 years ago are still visible in the planet's atmosphere today, and they left behind persistent chemical anomalies that scientists can't fully explain.

In other words, long after a megastorm fades from view, its impact on Saturn's weather lasts centuries.

"For most of the time, Saturn's atmosphere looks hazy and featureless to the naked eye in contrast to Jupiter's colorful and vibrant atmosphere," the researchers wrote in a study published Aug. 11 in the journal Science Advances. "This picture changes when we look at Saturn using a radio eye."

Related: Strange radio signals detected from Earth-like planet could be a magnetic field necessary for life

Using the Very Large Array radio telescope in New Mexico, the study authors peered through the haze of Saturn's upper atmosphere, hoping to find chemical remnants of the vast 2010 megastorm. In fact, the team found traces of all six recorded megastorms, the earliest of which hit more than 130 years ago, as well as a potentially new storm never recorded before.

Visible only in radio wavelengths, those remnants took the form of large ammonia gas anomalies. Saturn's uppermost cloud layer is made mainly of ammonia-ice clouds. But in their radio observations, the researchers saw regions of unexpectedly low ammonia concentrations just below this cloud layer in areas associated with past storms. Meanwhile, hundreds of miles below these same atmospheric regions, ammonia concentrations spiked much higher than normal.

The implication, according to the study authors, is that megastorms appear to drive some mysterious ammonia transport process that drags ammonia gas from Saturn's upper atmosphere into the depths of the lower atmosphere — possibly in the form of a "mushball" rain in which icy hail balls of ammonia fall through the atmosphere before reevaporating again. This mushy process appears to last hundreds of years after a storm visibly vanishes, the researchers wrote.

While the mechanisms behind these atmospheric anomalies — and behind Saturn's megastorms in general — remain a mystery, studying them further could broaden not only our understanding of how giant planets form but also of what drives storm systems like Saturn's Great White Spots and Jupiter's even larger Great Red Spot to grow so inexplicably large, according to the researchers.

"Understanding the mechanisms of the largest storms in the solar system puts the theory of hurricanes into a broader cosmic context, challenging our current knowledge and pushing the boundaries of terrestrial meteorology," lead study author Cheng Li, formerly at the University of California, Berkeley and now an assistant professor at the University of Michigan, said in a statement.

In early July, the moon will pass close to all three of Earth's neighboring  inner solar system planets, plus the two largest planets that orbit the sun.

First, the gas giants Saturn and Jupiter will be viewable next to the moon before sunrise early in the month. Later in July, Mercury, Venus and Mars will shine close to a crescent moon after sunset.

All five planets and Earth's moon will be easily visible to the naked eye from anywhere in the world with clear skies. However, a good pair of stargazing binoculars or a nice small telescope will enhance the view. 

The first conjunction (a celestial event in which two objects appear close together in Earth's night sky) of the moon and a planet will occur on July 7, when an 80%-lit waning gibbous moon will be visible just below Saturn. The two objects will rise in the southeastern night sky in the early morning and will be visible until dawn. 

On July 11, a 37%-lit waning gibbous moon, positioned slightly above Jupiter, will rise in the east late at night. The following morning, the moon will have waned to 27% illumination and will be visible just below Jupiter. 

Mercury, Venus and Mars — the other three rocky planets in the solar system — will be closely grouped with a slender waxing gibbous crescent moon in the early-evening western night sky from July 19 to July 21. 

Because the crescent moon will be barely 5% lit on July 19, however, this will be the hardest night to see it close to the rocky planets. That will also be true for Mercury, which will be very low on the horizon. However, bright Venus will be obvious alongside the crescent moon, while Mars will be easily seen above. Don't mistake Mars for Regulus, the brightest star in Leo, which will sit between Venus and Mars. Use binoculars, find a clear view toward the western horizon and begin looking about 35 minutes after sunset, according to When The Curves Line Up, a site run by astronomer Jeffrey Hunt.

On July 20 — the 54th anniversary of Apollo 11, the first moon landing — the crescent moon will be much easier to see. As well as being 10% lit, the moon will have climbed higher and will shine alongside Mars, just above Venus. Mercury will remain low on the west-northwest horizon. While you're gazing at the trio of planets, look for "Da Vinci glow" on the dark limb of the moon. Also called Earthshine, the phenomenon is caused by reflected sunlight from Earth's oceans, clouds and ice. 

The following evening, July 21, a 16%-lit crescent moon will appear even higher above the western horizon, but it will be aligned with Mars and Venus. Mercury will be to the right of Venus. 

On the following nights, the moon will depart the scene and climb higher into the post-sunset sky, with Venus sinking into the sun's glare while Mercury continues to rise above it. On July 28, Mercury will shine within just a tenth of a degree of Regulus in twilight, according to Adler Planetarium. It should be an excellent sight, even to the naked eye. 

You can check the exact rise and set times for the planets for your location using the Night Sky page on timeanddate, or planetarium software such as Stellarium Web Online Star Map. 

The James Webb Space Telescope (JWST) has become synonymous with jaw-dropping, full-color photos of some of the most compelling cosmic landscapes in the universe. But, as new photos of Saturn reveal, even JWST's unprocessed black-and-white images are stunning.

JWST captured the new images of the ringed planet between June 24 and 25 as part of a project led by Leigh Fletcher, an astronomer at the University of Leicester in the U.K., to study the planet's rings, moons and atmospheric composition. The pictures recently appeared on the telescope's unofficial live feed. However, they don't look like the banded gold orb you might imagine  — at least, not yet. 

Currently, the pictures are in stark — and somewhat eerie — black and white. In some of the images, Saturn and its rings look almost overly saturated with light. This is intentional; the black-and-white pixels actually represent a detailed account of the number of photons that the JWST's Near Infrared Camera collected. Later, scientists will process and colorize the images into something more instantly recognizable. For now, they remain a ghostly and rarely seen portrait of the planet's icy rings.

Although the JWST has been operational for less than a year, it has already revolutionized our understanding of the universe and captured some of the most valuable — and some of the most beautiful — scientific photos ever produced. The telescope, which has three cameras, is designed to peer into the infrared spectrum. This allows it to capture light from the oldest stars in the universe, thanks to a phenomenon known as redshift. 

As light travels, its wavelengths stretch from the short ultraviolet end of the spectrum to the long infrared end. Because of this, light from the universe's very oldest (and most distant) stars can only be detected in the infrared spectrum by very powerful instruments. But, as the new Saturn images show, the JWST can also snap breathtaking pictures much closer to home.

Saturn isn't the first body in our solar system to get a JWST photoshoot. Earlier this year, the telescope also captured gorgeous images of Uranus, revealing the giant planet's lesser-known rings in stunning detail. And last summer, the JWST snapped incredibly detailed photos of Saturn's neighbor, Jupiter.