Debris from a cosmic explosion bumped into a neighboring star, a new study reports, suggesting that the surviving star might be responsible for its partner’s demise.

The explosion, known as a type 1a supernova, was discovered in 2012. It went off in a galaxy about 50 million light-years away in the constellation Virgo. Astronomers quickly noticed more blue light coming from the supernova than expected. The excess light probably came from gas that was compressed and heated as the shock wave ran into another star, Howie Marion, an astronomer at the University of Texas at Austin, and colleagues report online March 22 in the Astrophysical Journal. It’s the first strong evidence that some normal type 1a supernovas have orbiting companions.

Astronomers suspect that a type 1a supernova is the detonation of a white dwarf, the dense core left behind after some stars die. What pulls the trigger is up for debate. Two white dwarfs could spiral together and explode. Or one white dwarf could siphon gas off of a companion star until the white dwarf could no longer support its own weight, triggering a destructive regurgitation. Seeing glowing gas from the shock wave slamming into a companion supports the idea that some white dwarfs eat until they explode.

Last year, researchers reported similar observations from another supernova (SN: 6/27/15, p. 9), but that explosion was just one one-thousandth as bright as a typical type 1a. It might not be representative of all type 1a supernovas, which are frequently used as distance markers that help measure the expansion of the universe.

In the 1967 animated Disney film The Jungle Book, the feral boy Mowgli encounters a jazz-singing orangutan named King Louie, who implores Mowgli to teach him the secret of fire. King Louie presented a challenge for the producers of Disney’s live-action, CGI-enhanced remake of the film, opening April 15. “We had this notion that we would be as authentic as we could be to the region,” says producer Brigham Taylor. The problem: Orangutans are not native to India.
In fact, King Louie himself is not native to Rudyard Kipling’s original stories. But instead of scrapping the character, the filmmakers got creative. While researching India’s wildlife, the film’s art department learned that a colossal ape named Gigantopithecus once roamed the region. Various species of Gigantopithecus lived in India, China and Southeast Asia from about 6.5 million years ago until as recently as a few hundred thousand years ago. The ape was truly gigantic — by some estimates, twice as big as a gorilla.

So King Louie morphed from orangutan to Gigantopithecus. The switch was a “fun justification,” Taylor says, to keep the character and play up his size while still staying true to India’s fauna. (Yes, the ape is extinct, but this is a movie about talking animals. And fossil evidence does suggest that the ape at least mingled with the human ancestor Homo erectus.)

Using the scientific information they could find on the Internet, visual effects artists imagined how the animal would look and move, Taylor says. The result: an ape that resembles an overgrown orangutan, Gigantopithecus’ closest living relative. The movie ape has shaggy hair, flaring cheeks and a saggy pouch that hangs from the throat like a double chin — and towers about 12 feet tall.
It’s difficult to judge how accurate Disney’s rendering is. Despite possibly having been the largest primate ever to have lived, Gigantopithecus
left behind few fossils. Scientists have just four lower jaws and over a thousand teeth, says biological anthropologist Russell Ciochon of the University of Iowa. That’s not much to go on, but Ciochon and colleagues made their own reconstruction a couple decades ago.
The researchers took a jaw from China and made an outline of a skull that could fit such a jaw. Because most primate skulls scale to body size, Ciochon says, his group could estimate Gigantopithecus’ weight, 800 to 900 pounds, and height, about 9 feet from head to toe. (The species that lived in India was actually probably smaller.) Adding other details like hair to the animal is a matter of conjecture, Ciochon says.

But the teeth do offer some solid details about the ape’s lifestyle. Wear patterns and microscopic debris stuck to the teeth indicate Gigantopithecus dined on fruits, leaves, shoots, roots and perhaps even bamboo. Last year, researchers confirmed those details after analyzing the ratios of carbon isotopes in teeth found in Southeast Asia. The analysis also determined that Gigantopithecus was a strict forest dweller, even though it also lived near grasslands in some areas. In fact, the researchers contend, Gigantopithecus’ reliance on forests and its big size — and therefore big appetite — may have been the animal’s undoing. As Southeast Asia’s jungles gave way to expanding grasslands during the last glacial period, Gigantopithecus may have been unable to cope.

Perhaps if our ancestors had shared the secret of fire with Gigantopithecus, the giant ape would still be around today.

Corals are in hot water — and may soon lose their ability to handle the heat.

In Australia’s Great Barrier Reef, most past bouts of warming allowed many corals to adjust their physiology and avoid serious damage. But as waters warm even more, corals could run out of wiggle room, researchers report in the April 15 Science.

“One of the things that we have been striving for is trying to figure out the rate and limit of … physiological adjustments that corals have, how far you can push them,” says marine biologist Stephen Palumbi of Stanford University, who was not involved with the study. Corals may not be able to cope with much more ocean warming, Palumbi says. “I would take this paper as being the first real indication that we have half a degree at most.”
If water temperatures surge quickly, corals may bleach, losing the bacterial residents that provide them with nutrients and oxygen (and color). But if waters warm slightly — less than the roughly 2 degrees Celsius above average heat spike where bleaching begins — and then cool for a brief time before heating up to a greater extent, corals are better prepared to survive the heat. In the lab, corals exposed to this two-step heating process experienced less bleaching and less cell death than corals suffering a high initial heat wave, the researchers found.

“We liken it to the idea of training for a marathon,” says study coauthor Scott Heron, a physical oceanographer with the National Oceanic and Atmospheric Administration’s Coral Reef Watch in College Park, Md. “If they have a little bit of exposure, and then the recovery period after that … they’re better prepared for the race when it comes.”

From 1985 to 2011, around 75 percent of warming events on Great Barrier Reef sites occurred in this stepwise fashion, probably allowing corals to steel themselves and survive warmer waters. But with climate models predicting a 2-degree increase in sea temperatures by the end of the century, warming events could soon push corals past their bleaching point with no chance to prepare.

Computer simulations predicted that as waters grow warmer, reef heat waves will increase overall. But the fraction of such events that could condition corals to withstand bleaching will fall from 75 percent to 22 percent, the team reports. Most reefs that have experienced preconditioning in the past will start losing the ability to prepare when water temperatures increase by 0.5 degrees, the team predicts. Warming trends suggest that the added half degree should appear within 40 years. “If that protective mechanism does get lost going into the future, then what we’ve seen so far as being bad impacts could become worse,” Heron says.

For now, preparation may help some corals survive in warming seas, but reduced carbon emissions will also be required to sustain coral cover throughout the century, the team’s data suggest. Palumbi says these predictions are very important. “If we get a handle on emissions, there are substantial predicted differences in the way that coral populations live in the future,” he says. “We are still in a position to choose how the future of coral reefs works out.”

A baby titanosaur looked a lot like a grown-up — and it probably acted like one, too.

The (relatively) tiny fossils of a roughly 1- to 2-month-old dinosaur, Rapetosaurus krausei, discovered in what is now Madagascar, suggest that babies and adults had similar limb proportions, researchers report in the April 22 Science. That’s a sign that the babies were precocious, or didn’t require a whole lot of parental care, says study coauthor Kristi Curry Rogers, a vertebrate paleontologist at Macalester College in St. Paul, Minn. After hatching, she says, the tiny titanosaur may have been more self-reliant than babies of other dinosaur species.

A lack of very young titanosaur specimens has made it tough to understand the enormous dinosaurs’ growth patterns. Curry Rogers and colleagues estimate that when newly hatched, the baby weighed 3.4 kilograms — about the weight of a newborn human. But in just a few weeks, the dinosaur’s weight shot up to 40 kilograms, roughly as heavy as a 12-year-old boy.

During the growth spurt, all of the baby’s limbs grew at about the same rate, the team calculated with data from microscopic images and CT scans. Those data plus features of the bones’ tissue point toward a life that, though cut short by starvation, was both active and independent.

In the summer of 2013, an epidemic began sweeping through the intertidal zone off the west coast of North America. The victims were several species of sea star, including Pisaster ochraceus, a species that comes in orange and purple variants. (It’s also notable because it’s the starfish that provided ecology with the fundamental concept of a keystone species.) Affected individuals appeared to “melt,” losing grip with the rocks to which they were attached — and then losing their arms. This sea star wasting disease, as it is known, soon killed sea stars from Baja California to Alaska.

This wasn’t the first outbreak of sea star wasting disease. A 1978 outbreak in the Gulf of California, for instance, killed so many Heliaster kubinjiisun stars that the once ubiquitous species is now incredibly rare.

These past incidents, though, happened fast and within smaller regions, so scientists had struggled to figure out what had happened. With the latest outbreak happening over such a large — and well-studied — region and period of time, marine biologists have been able to gather more data on the disease than ever before. And they’re getting closer to figuring out just what happened in this latest incident.

One likely factor is the sea star-associated densovirus, which, in 2014, scientists reported finding in greater abundance in starfish with sea star wasting disease than in healthy sea stars. But the virus can’t be the only cause of the disease; it’s found in both healthy and sick sea stars, and it has been around since at least 1942, the earliest year it has been found in museum specimens. So there must be some other factor at play.
Earlier this year, scientists studying the outbreak in Washington state reported in the Proceedings of the Royal Society B thatwarm waters may increase disease progression and rates of death. Studies of California starfish came to a similar conclusion. But a new study, appearing May 4 in PLOS One , finds that may not be true for sea stars in Oregon. Bruce Menge and colleagues at Oregon State University took advantage of their long-term study of Oregon starfish to evaluate what happened to sea stars during the recent epidemic and found that wasting disease increased with cooler , not warmer, temperatures. “Given conflicting results on the role of temperature as a trigger of [sea star wasting disease], it seems most likely that multiple factors interacted in complex ways to cause the outbreak,” they conclude.
What those factors are, though, is still a mystery.

Also unclear is what long-term effects this outbreak will have on Pacific intertidal communities.

In the 1960s, Robert Paine of the University of Washington performed what is now considered a classic experiment. For years, he removed starfish from one area of rock in Makah Bay at the northwestern tip of Washington and left another bit of rock alone as a control. Without the starfish to prey on them, mussels were able to take over. The sea stars, Paine concluded, were a “keystone species” that kept the local food web in control.

If sea star wasting disease has similar effects on the Pacific intertidal food web, Menge and his colleagues write, “it would result in losses or large reductions of many species of macrophytes, anemones, limpets, chitons, sea urchins and other organisms from the low intertidal zone.”

What happens, the group says, may depend on how quickly the disease disappears from the region and how many young sea stars can grow up and start munching on mussels.

It’s hard to believe that it took reality television this long to get around to dealing with space, time and our place in the cosmos.

In PBS’ Genius by Stephen Hawking, the physicist sets out to prove that anyone can tackle humankind’s big questions for themselves. Each of the series’ six installments focuses on a different problem, such as the possibility of time travel or the likelihood that there is life elsewhere in the universe. With Hawking as a guide, three ordinary folks must solve a series of puzzles that guide them toward enlightenment about that episode’s theme. Rather than line up scientists to talk at viewers, the show invites us to follow each episode’s trio on a journey of discovery.
By putting the focus on nonexperts, Genius emphasizes that science is not a tome of facts handed down from above but a process driven by curiosity. After working through a demonstration of how time slows down near a black hole, one participant reflects: “It’s amazing to see it play out like this.”
The show is a fun approach to big ideas in science and philosophy, and the enthusiasm of the guests is infectious. Without knowing what was edited out, though, it’s difficult to say whether the show proves Hawking’s belief that anyone can tackle these heady questions. Each situation is carefully designed to lead the participants to specific conclusions, and there seems to be some off-camera prompting.

But the bigger message is a noble one: A simple and often surprising chain of reasoning can lead to powerful insights about the universe, and reading about the cosmos pales next to interacting with stand-ins for its grandeur. It’s one thing, for example, to hear that there are roughly 300 billion stars in the Milky Way. But to stand next to a mountain of sand where each grain represents one of those stars is quite another. “I never would have got it until I saw it,” says one of the guests, gesturing to the galaxy of sand grains. “This I get.”

In hunting down delicious fish, Flipper may have a secret weapon: snot.

Dolphins emit a series of quick, high-frequency sounds — probably by forcing air over tissues in the nasal passage — to find and track potential prey. “It’s kind of like making a raspberry,” says Aaron Thode of the Scripps Institution of Oceanography in San Diego. Thode and colleagues tweaked a human speech modeling technique to reproduce dolphin sounds and discern the intricacies of their unique style of sound production. He presented the results on May 24 in Salt Lake City at the annual meeting of the Acoustical Society of America.

Dolphin chirps have two parts: a thump and a ring. Their model worked on the assumption that lumps of tissue bumping together produce the thump, and those tissues pulling apart produce the ring. But to match the high frequencies of live bottlenose dolphins, the researchers had to make the surfaces of those tissues sticky. That suggests that mucus lining the nasal passage tissue is crucial to dolphin sonar.

The vocal model also successfully mimicked whistling noises used to communicate with other dolphins and faulty clicks that probably result from inadequate snot. Such techniques could be adapted to study sound production or echolocation in sperm whales and other dolphin relatives.
Researchers modified a human speech model developed in the 1970s to study dolphin echolocation. The animation above mimics the vibration of lumps of tissue (green) in the dolphin’s nasal passage (black) that are drenched in mucus. Snot-covered tissues (blue) stick together (red) and pull apart to create the click sound.

Jupiter’s turbulence is not just skin deep. The giant planet’s visible storms and blemishes have roots far below the clouds, researchers report in the June 3 Science. The new observations offer a preview of what NASA’s Juno spacecraft will see when it sidles up to Jupiter later this year.

A chain of rising plumes, each reaching nearly 100 kilometers into Jupiter, dredges up ammonia to form ice clouds. Between the plumes, dry air sinks back into the Jovian depths. And the famous Great Red Spot, a storm more than twice as wide as Earth that has churned for several hundred years, extends at least dozens of kilometers below the clouds as well.

Jupiter’s dynamic atmosphere provides a possible window into how the planet works inside. “One of the big questions is what is driving that change,” says Leigh Fletcher, a planetary scientist at the University of Leicester in England. “Why does it change so rapidly, and what are the environmental and climate-related factors that result from those changes?”

To address some of those questions, Imke de Pater, a planetary scientist at the University of California, Berkeley, and colleagues observed Jupiter with the Very Large Array radio observatory in New Mexico. Jupiter emits radio waves generated by heat left over from its formation about 4.6 billion years ago. Ammonia gas within Jupiter’s atmosphere intercepts certain radio frequencies. By mapping how and where those frequencies are absorbed, the researchers created a three-dimensional map of the ammonia that lurks beneath Jupiter’s clouds. Those plumes and downdrafts appear to be powered by a narrow wave of gas that wraps around much of the planet.

The depths of Jupiter’s atmospheric choppiness isn’t too surprising, says Scott Bolton, a planetary scientist at the Southwest Research Institute in San Antonio. “Almost everyone I know would have guessed that,” he says. But the observations do provide a teaser for what to expect from the Juno mission, led by Bolton. The spacecraft arrives at Jupiter on July 4 to begin a 20-month investigation of what’s going on beneath Jupiter’s clouds using tools similar to those used in this study.

The new observations confirm that Juno should work as planned, Bolton says.

By getting close to the planet — just 5,000 kilometers from the cloud tops — Juno will break through the fog of radio waves from Jupiter’s radiation belts that obscures observations made from Earth and limits what telescopes like the Very Large Array can see. But the spacecraft will see only a narrow swath of Jupiter’s bulk at a time. “That’s where ground-based work like the research de Pater has been doing is really essential,” Fletcher says. Observations such as these will let Juno scientists know what’s going on throughout the atmosphere so they can better understand what Jupiter is telling them.

In a chorus of indris, young males vie for the spotlight, riffing in alternation rather than singing in unison. Not content to be the Joey Fatone of the group, these guys strive for Justin Timberlake status.

Indris (Indri indri), the only singing lemur species, begin their songs with roars that descend into long, phrased howls. These choirs are composed of males and females, with one dominant pair. Marco Gamba of the University of Turin in Italy and his colleagues wanted to analyze variation among individual singers.

Listening to 496 indri songs recorded over 10 years in the dense forests of Madagascar, the team found that pitch varies between males and females. And indri groups typically sing in synchrony, amplifying their tunes and vocally marking their territory to other groups. When one singer starts to croon, the others join in and match rhythm.

Solos are rare, but young male singers tend to sing out of sync — probably to stand out and advertise their masculinity, Gamba and his colleagues propose June 14 in Frontiers in Neuroscience.

There are degrees of slothfulness, it turns out, even when it comes to sloths. And three-toed sloths may be the most slothful of them all: A species of the animal has a field metabolic rate that is the lowest ever recorded for any mammal in the world.

Jonathan Pauli, an ecologist at the University of Wisconsin-Madison, got interested in sloths not because they’re adorable but because “other things eat them,” he says. And he stayed interested in the animals because they are “biologically fascinating.”

Sloths are a type of arboreal folivore, a group that includes all animals that live in trees and eat only leaves. What most people lump into the category of “sloth” are really six species in two families (two-toed and three-toed) separated by millions of years of evolution. Both families live in trees in Central and South America and eat leaves, but three-toed sloths tend to have smaller ranges and more constricted diets, eating from only a few species of trees and only a limited number of them. Studies have also shown that these sloths have a very slow metabolic rate.

But how slow? To find out, Pauli and his colleagues captured 10 brown-throated three-toed sloths (Bradypus variegatus) and 12 Hoffmann’s two-toed sloths (Choloepus hoffmanni) from a study site in northeastern Costa Rica. There, the sloths live among a variety of habitat types, ranging from pristine forest to cacao agroforest to monocultures of banana and pineapple. “It’s really a quilt of different habitat types,” Pauli says, and one that allows the researchers to not only study many habitats at once but also more easily capture and track sloths than if they were in dense jungle.

The researchers injected the sloths with water labeled with isotopes of oxygen and hydrogen and released the animals, tracking them with radiotelemetry. After a week to a week and a half, the scientists again captured the sloths and took blood samples. By seeing how much of the oxygen and hydrogen isotopes remained, the scientists could calculate the sloths’ field metabolic rate — the energy that an organism uses throughout the day.

The field metabolic rate for the three-toed sloths was 31 percent lower than that of two-toed sloths and lower than that found in any mammal outside of hibernation, the researchers report May 25 in the American Naturalist.

“There seems to be kind of a cool combination of behavior and physiological characteristics that lead to these tremendous cost savings for three-toed sloths,” Pauli says. Three-toed sloths spend a lot of time in the canopy eating and sleeping, he notes. “They don’t do a lot of movement, whereas two-toed sloths are much more mobile. They’re moving around a lot more.”

But it’s more than just that. “Three-toed sloths have the capacity to fluctuate their body temperature,” he says. Unlike humans, who need to keep their temperature within a few degrees to function properly, the sloths can let theirs rise and fall with the ambient temperature, a bit like how a lizard or snake might regulate its body temperature. “Those are big cost savings to let your body change with your surroundings.”

The results of the study help explain why there aren’t more kinds of sloths and other arboreal folivores, Pauli and his colleagues argue. “Being an arboreal folivore is really tough living,” Pauli says. Leaf eaters tend to be big because they need to accommodate a large digestive system capable of processing all the leaf matter they need to survive. But to live in the trees, an animal can’t be too big. And this could be why arboreal folivory is one of the world’s rarest lifestyles. The need for all the various adaptations for that lifestyle could prevent the rapid diversification seen among other groups, such as Darwin’s finches.