Each week at Live Science we find the most interesting and informative articles we can. Along the way, we uncover some amazing and cool images. Here you'll discover the most incredible photos we found this week, and the remarkable stories behind them.
America's chonkiest bear
Looking for a distraction from the dumpster fire that is the 2020 election? Then this is your reminder to weigh in on a very different election: Choosing the chonkiest grizzly bear in Katmai National Park as part of Fat Bear Week. The annual competition allows internet users to select the heftiest grizzly bear at the park’s Brooks River in Alaska.
The bears are currently at the river gorging on salmon in preparation for winter hibernation. Social media’s enthusiasm for the competition is so intense that voters briefly crashed the voting website on Wednesday (Sept. 30). Bracket-style voting runs through Oct. 6, at which point a winning bear will be crowned fattest of the season. Mama Bear 402 (shown above) was recently knocked out of the contest by blubbery newcomer, Bear 812.
The voting is entirely subjective and can be based on weight gain, overall size or challenges that the bears have overcome. Simply vote with your eyes, your heart and your strong inner desire to hibernate until springtime.
Read more: It's time to vote for the chonkiest bear in Katmai National Park
The naked shark of Sardinia
In July 2019, fishers trawling the Mediterranean Sea south of Sardinia, Italy, accidentally pulled a mutant from the depths. Ensnared in their net among hundreds of other fish, sharks and assorted marine life was a blackmouth catshark (Galeus melastomus) — seemingly born without skin or teeth.
While scientists have reported numerous cases of albinism, discoloration and other genetic skin mutations in sharks before, this rare catch is the first and only known case of a shark living with a "severe lack of all skin-related structures [including] teeth," according to a study published July 16 in the Journal of Fish Biology.
Perhaps stranger still, the abnormal shark seemed to be living a relatively normal life until it was scooped from the sea, lead study author Antonello Mulas said. When he and his colleagues examined the shark, they found that it was about 3 years old, had grown at a typical rate, and had a belly full of food when it died. The shark's appearance was almost certainly the result of a genetic mutation, the researchers said.
Read more: 'Naked' shark was born without skin or teeth in world first
Probes over Venus
If life does exist on Venus, NASA may have first detected it back in 1978. But the finding went unnoticed for 42 years.
Life on Venus is still a long shot. But there's reason to take the idea seriously. On Sept. 14, a team of scientists made a bombshell announcement in the journal Nature Astronomy: Using telescopes, they'd detected phosphine, a toxic gas long proposed as a possible sign of alien microbial life, in the upper part of the planet's thick atmosphere.
Now, digging through archival NASA data, Rakesh Mogul, a biochemist at Cal Poly Pomona in California, and colleagues have found a hint of phosphine picked up by Pioneer 13 — a probe that reached Venus in December 1978. The discovery, published to the arXiv database Sept. 22 and not yet peer reviewed, doesn't tell researchers much beyond what was reported in Nature Astronomy — though it does make the presence of phosphine even more certain, they said. The 1978 data comes from the Large Probe Neutral Mass Spectrometer (LNMS), one of several instruments that descended into Venus' atmosphere as part of the Pioneer 13 mission (illustrated above).
Read more: Did NASA detect a hint of life on Venus in 1978 and not realize it?
Sneak attack in ancient Spain
A brutal attack on an Iron Age town in northern Spain during the mid-fourth or late third century B.C. left more than a dozen bodies — men, women and children — scattered and smoldering in the streets, as the town burned. Injuries inflicted upon the people who died were horrific. One person was decapitated, two had severed arms, and the remains of nearly half of the individuals showed signs of mutilation, archaeologists recently discovered.
New analysis of the victims' bones — the first detailed investigation of their injuries — suggests that they were murdered by a neighboring community during either a calculated power grab or an act of revenge.
The site of the massacre was once a bustling, economically thriving town called La Hoya, located in northern Spain's Rioja Alavesa region. It was occupied from the 15th century B.C. to the third century B.C., and at its peak was home to about 1,500 people. Since excavations began in 1973, researchers have uncovered an increasingly grisly story. Burned skeletons — at least 13 complete and partial remains — were found lying in the streets and inside buildings. Researchers found no signs of weapons near the bodies nor any defensive wounds, suggesting the victims died in a mysterious surprise attack.
Read more: Decapitated and dismembered skeletons reveal lost Iron Age massacre
Antarctica without ice
Antarctica contains more than half of the world's freshwater in its sprawling, frozen ice sheet, but humanity's decisions over the next century could send that water irreversibly into the sea. If global warming is allowed to continue unchecked, Antarctica will soon pass a "point of no return" that could reduce the continent to a barren, ice-free mass for the first time in more than 30 million years, according to a new study published Sep. 23 in the journal Nature.
"Antarctica is basically our ultimate heritage from an earlier time in Earth's history. It's been around for roughly 34 million years," study co-author Anders Levermann, a researcher at the Potsdam Institute for Climate Impact Research (PIK) in Germany, said in a statement. "Now our simulations show that once it's melted, it does not regrow to its initial state [until] temperatures go back to pre-industrial levels … a highly unlikely scenario. In other words: What we lose of Antarctica now, is lost forever."
In the study, PIK researchers ran computer simulations to model how Antarctica will look thousands of years from now, depending on how high average global temperatures rise in response to modern greenhouse gas emissions. They found that if global temperatures rise by 18 F (10 C) for any sustained period of time, the continent is doomed to be "virtually ice-free" within 200,000 years. Should the continent lose all of its ice, global sea levels will rise by nearly 200 feet (58 m).
Read more: Antarctica could melt 'irreversibly' due to climate change, study warns
Hissss, slash, yum!
Pity the toads that encounter Asian kukri snakes in Thailand. These snakes use enlarged, knifelike teeth in their upper jaws to slash and disembowel toad prey, plunging their heads into the abdominal cavities and feasting on the organs one at a time while the toads are still alive, leaving the rest of the corpse untouched.
While you're recovering from the horror of that sentence, "perhaps you'd be pleased to know that kukri snakes are, thankfully, harmless to humans," amateur herpetologist and naturalist Henrik Bringsøe, lead author in a new study describing the gruesome technique, said in a statement.
This grisly dining habit was previously unknown in snakes; while some rip chunks from their prey, most snakes gulp down their meals whole. Scientists had never before seen a snake Bury its head inside an animal's body to slurp up organs — sometimes taking hours to do so, Bringsøe and his colleagues reported.
Read more: Snakes disembowel toads and feast on the living animal's organs one by one
Caligula's close-up
Ancient Roman emperors' faces have been brought to life in digital reconstructions; the unnervingly realistic image project includes the Emperors Caligula, Nero and Hadrian, among others.
The features of these long-dead rulers have been preserved in hundreds of sculptures, but even the most detailed carvings can't convey what these men truly looked like when they were alive. To explore that, Canadian cinematographer and virtual reality designer Daniel Voshart used a neural network called Artbreeder to analyze 800 busts and model more realistic facial shapes, features, hair and skin, and to add vivid color. Voshart then fine-tuned Artbreeder's models using Photoshop, adding details gleaned from coins, artworks and written descriptions of the emperors from historical texts, to make the portraits really come to life.
For the emperor Caligula (shown above), who ruled from A.D. 37 to 41, Voshart adjusted the Artbreeder model using descriptions that included "head misshapen, eyes and temples sunken," and "eyes staring and with a glare savage enough to torture," from a paper titled "Personal Appearance in the Biography of the Roman Emperors," published in 1928 in the journal Studies in Philology.
Read more: AI 'resurrects' 54 Roman emperors, in stunningly lifelike images
Brain surgery 101
A Stone Age skull found in a Spanish cave bears the marks of a failed brain surgery and postmortem decapitation.
The skull, which may have belonged to an adult woman, dates back to approximately 4800 B.C. to 4550 B.C. Archaeologists found the skull deep inside Dehesilla Cave on the Iberian peninsula, alongside a second adult skull — perhaps from a man — and the remains of a young goat, they reported Aug. 13 in the journal PLOS ONE.
The morbid and unusual discovery raises the possibility that the bones were brought to the cave for some sort of religious ritual, study author Daniel García-Rivero, an archaeologist at the University of Seville in Spain, wrote in the paper. One or both of the individuals may have even been victims of human sacrifice.
Read more: Failed brain surgery and possible human sacrifice revealed in Stone Age burial
The wet Red Planet
Remnants of water once found on the surface of Mars may be hidden in a handful of small lakes below the Red Planet's south pole, and more could exist, according to new research.
For decades, researchers have suspected that water lurks below the polar icecaps of Mars, just as it does here on Earth. In 2018, scientists detected evidence for such a reservoir on the Red Planet — signs of a lake about 12 miles (19 kilometers) across and hidden below about a mile (1.5 km) of ice at the south pole of Mars.
In the new study, to learn more about this hidden water, researchers used the MARSIS radar sounder instrument on board the European Space Agency's Mars Express spacecraft to scan a 155-by-185 mile (250-by-300 km) area surrounding the suspected underground lake. The scientists confirmed the liquid nature of the previously observed lake, narrowing down its dimensions to about 12 by 18 miles (20 by 30 km) in size. Moreover, the researchers identified three other lakes on the order of 6 by 6 miles (10 by 10 km) in size. Strips of dry rock separate these smaller patches of water from the main lake, the scientists said.
Read more: 4 supersalty lakes may be hiding under the ice cap at Mars' south pole
Worm on the mind
A young woman in Australia was found to have tapeworm larvae lurking in her brain — a very unusual diagnosis considering she had no risk factors for the condition, according to a new report of the case. Indeed, it's believed to be the first "locally acquired" case of the disease in Australia, that is, in someone who hadn't traveled out of the country, the report said.
The 25-year-old woman went to the hospital after experiencing headaches for a week, according to the report, published Sept. 21 in The American Journal of Tropical Medicine and Hygiene. It didn't go away when she took painkillers, which usually cured her headaches, and her vision became blurry at times.
An MRI of her head revealed a single brain lesion, which doctors suspected was either a brain abscess or tumor. But when doctors performed brain surgery to remove the lesion, they got a surprise. The lesion was really a cyst, and it wasn't made of human tissue. Further tests revealed that the cyst contained tapeworm larvae. The woman was diagnosed with neurocysticercosis, a parasitic disease that occurs when a person ingests microscopic eggs from a pork tapeworm (Taenia solium).
Read more: Woman's odd headache was from tapeworm larvae in her brain
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Originally published on Live Science.