NASA’s DART spacecraft just smashed into an asteroid — on purpose

Mission control rooms rarely celebrate crash landings. But the collision of NASA’s DART spacecraft with an asteroid was a smashing success.

At about 7:15 p.m. EDT on September 26, the spacecraft hurtled into Dimorphos, an asteroid moonlet orbiting a larger space rock named Didymos. The mission’s goal was to bump Dimorphos slightly closer to its parent asteroid, shortening its 12-hour orbit around Didymos by several minutes.

The Double Asteroid Redirection Test, or DART, is the world’s first attempt to change an asteroid’s motion by ramming a space probe into it (SN: 6/30/20). Neither Dimorphos nor Didymos poses a threat to Earth. But seeing how well DART’s maneuver worked will reveal how easy it is to tamper with an asteroid’s trajectory — a strategy that could protect the planet if a large asteroid is ever discovered on a collision course with Earth.

“We don’t know of any large asteroids that would be considered a threat to Earth that are coming any time in the next century,” says DART team member Angela Stickle, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “The reason that we are doing something like DART is because there are asteroids that we haven’t discovered yet.”
Astronomers have spotted almost all the kilometer-size asteroids in the solar system that could end civilization if they hit Earth, says Jessica Sunshine, a planetary scientist at the University of Maryland in College Park who’s also on the DART team. But when it comes to space rocks around 150 meters wide, like Dimorphos, “we only know where about 40 percent of those are,” Sunshine says. “And that is something that, if it did hit, would certainly take out a city.”

Dimorphos is a safe asteroid to give an experimental nudge, says Mark Boslough, a physicist at Los Alamos National Laboratory in New Mexico who has studied planetary protection but is not involved in DART. “It’s not on a collision course” with Earth, he says, and DART “can’t hit it hard enough to put it on a collision course.” The DART spacecraft weighs only as much as a couple of vending machines, whereas Dimorphos is thought to be nearly as hefty as Egypt’s Great Pyramid of Giza.

After a 10-month voyage, DART met up with Didymos and Dimorphos near their closest approach to Earth, about 11 million kilometers away. Up until the very end of its journey, DART could see only the larger asteroid, Didymos. But about an hour before impact, DART spotted Dimorphos in its field of view. Using its onboard camera, the spacecraft steered itself toward the asteroid moonlet and slammed into it at some 6.1 kilometers per second, or nearly 14,000 miles per hour.
DART’s camera feed went dark after impact. But another probe nearby is expected to have caught the collision on camera. The Light Italian CubeSat for Imaging of Asteroids rode to Dimorphos aboard DART but detached a couple of weeks before impact to watch the event from a safe distance. Its mission was to whiz past Dimorphos about three minutes after DART’s impact to snap pictures of the crash site and the resulting plume of asteroid debris launched into space. The probe is expected to beam images of DART’s demise back to Earth within a couple of days.

“I was absolutely elated, especially as we saw the camera getting closer and just realizing all the science that we’re going to learn,” said Pam Melroy, NASA Deputy Administrator, after the impact. “But the best part was seeing, at the end, that there was no question there was going to be an impact, and to see the team overjoyed with their success.”
DART’s impact is expected to shove Dimorphos into a closer, shorter orbit around Didymos. Telescopes on Earth can clock the timing of that orbit by watching how the amount of light from the double asteroid system changes as Dimorphos passes in front of and behind Didymos.

“It’s really a beautifully conceived experiment,” Boslough says. In the coming weeks, dozens of telescopes across every continent will watch Dimorphos to see how much DART changed its orbit. The Hubble and James Webb space telescopes may also get images.
“It’ll be really interesting to see what comes out,” says Amy Mainzer, a planetary scientist at the University of Arizona in Tucson who is not involved in DART. “Asteroids have a way of surprising us,” she says, because it’s hard to know a space rock’s precise chemical makeup and internal structure based on observations from Earth. So Dimorphos’ motion post-impact may not exactly match researchers’ expectations.

The DART team will compare data on Dimorphos’ new orbit with their computer simulations to see how close those models were to predicting the asteroid’s actual behavior and tweak them accordingly. “If we can get our models to reproduce what actually happened, then you can use those models to [plan for] other scenarios that might show up in the future” — like the discovery of a real killer asteroid, says DART team member Wendy Caldwell, a mathematician and planetary scientist at Los Alamos National Laboratory.

“No matter what happens,” she says, “we will get information that is valuable to the scientific community and to the planetary defense community.”

A protogalaxy in the Milky Way may be our galaxy’s original nucleus

The Milky Way left its “poor old heart” in and around the constellation Sagittarius, astronomers report. New data from the Gaia spacecraft reveal the full extent of what seems to be the galaxy’s original nucleus — the ancient stellar population that the rest of the Milky Way grew around — which came together more than 12.5 billion years ago.

“People have long speculated that such a vast population [of old stars] should exist in the center of our Milky Way, and Gaia now shows that there they are,” says astronomer Hans-Walter Rix of the Max Planck Institute for Astronomy in Heidelberg, Germany.
The Milky Way’s ancient heart is a round protogalaxy that spans nearly 18,000 light-years and possesses roughly 100 million times the mass of the sun in stars, or about 0.2 percent of the Milky Way’s current stellar mass, Rix and colleagues report in a study posted September 7 at arXiv.org.

“This study really helps to firm up our understanding of this very, very, very young stage in the Milky Way’s life,” says Vasily Belokurov, an astronomer at the University of Cambridge who was not involved in the work. “Not much is really known about this period of the Milky Way’s life,” he says. “We’ve seen glimpses of this population before,” but the new study gives “a bird’s-eye view of the whole structure.”

Most stars in the Milky Way’s central region abound with metals, because the stars originated in a crowded metropolis that earlier stellar generations had enriched with those metals through supernova explosions. But Rix and his colleagues wanted to find the exceptions to the rule, stars so metal-poor they must have been born well before the rest of the galaxy’s stellar denizens came along — what Rix calls “a needle-in-a-haystack exercise.”

His team turned to data from the Gaia spacecraft, which launched in 2013 on a mission to chart the Milky Way (SN: 6/13/22). The astronomers searched about 2 million stars within a broad region around the galaxy’s center, which lies in the constellation Sagittarius, looking for stars with metal-to-hydrogen ratios no more than 3 percent of the sun’s.

The astronomers then examined how those stars move through space, retaining only the ones that don’t dart off into the vast halo of metal-poor stars engulfing the Milky Way’s disk. The end result: a sample of 18,000 ancient stars that represents the kernel around which the entire galaxy blossomed, the researchers say. By accounting for stars obscured by dust, Rix estimates that the protogalaxy is between 50 million and 200 million times as massive as the sun.

“That’s the original core,” Rix says, and it harbors the Milky Way’s oldest stars, which he says probably have ages exceeding 12.5 billion years. The protogalaxy formed when several large clumps of stars and gas conglomerated long ago, before the Milky Way’s first disk — the so-called thick disk — arose (SN: 3/23/22).

The protogalaxy is compact, which means little has disturbed it since its formation. Smaller galaxies have crashed into the Milky Way, augmenting its mass, but “we didn’t have any later mergers that deeply penetrated into the core and shook it up, because then the core would be larger now,” Rix says.

The new data on the protogalaxy even capture the Milky Way’s initial spin-up — its transition from an object that didn’t rotate into one that now does. The oldest stars in the proto–Milky Way barely revolve around the galaxy’s center but dive in and out of it instead, whereas slightly younger stars show more and more movement around the galactic center. “This is the Milky Way trying to become a disk galaxy,” says Belokurov, who saw the same spin-up in research that he and a colleague reported in July.

Today, the Milky Way is a giant galaxy that spins rapidly — each hour our solar system speeds through 900,000 kilometers of space as we race around the galaxy’s center. But the new study shows that the Milky Way got its start as a modest protogalaxy whose stars still shine today, stars that astronomers can now scrutinize for further clues to the galaxy’s birth and early evolution.

Drumming woodpeckers use similar brain regions as songbirds

Songbirds get a lot of love for their dulcet tones, but drummers may start to steal some of that spotlight.

Woodpeckers, which don’t sing but do drum on trees, have brain regions that are similar to those of songbirds, researchers report September 20 in PLOS Biology. The finding is surprising because songbirds use these regions to learn their songs at an early age, yet it’s not clear if woodpeckers learn their drum beats (SN: 9/16/21). Whether woodpeckers do or not, the result suggests a shared evolutionary origin for both singing and drumming.
The ability to learn vocalizations by listening to them, just like humans do when learning to speak, is a rare trait in the animal kingdom. Vocal learners, such as songbirds, hummingbirds and parrots, have independently evolved certain clusters of nerve cells called nuclei in their forebrains that control the ability. Animals that don’t learn vocally are thought to lack these brain features.

While it’s commonly assumed that other birds don’t have these nuclei, “there’s thousands of birds in the world,” says Matthew Fuxjager, a biologist at Brown University in Providence, R.I. “While we say these brain regions only exist in these small groups of species, nobody’s really looked in a lot of these other taxa.”

Fuxjager and his colleagues examined the noggins of several birds that don’t learn vocally to check if they really did lack these brain nuclei. Using molecular probes, the team checked the bird brains for activity of a gene called parvalbumin, a known marker of the vocal learning nuclei. Many of the birds, including penguins and flamingos, came up short, but there was one exception — male and female woodpeckers, which had three spots in their brains with high parvalbumin activity.

Though woodpeckers don’t sing, they do perform a rapid drumming on trees and house gutters to defend their territories or find mates. This drumming is different from the drilling the birds do to find food. When the team found brain nuclei similar to songbirds in woodpeckers, Fuxjager was immediately intrigued. “I thought right away it’s probably related to drumming,” he says.

The researchers subjected downy woodpeckers (Dryobates pubescens) in the wild to audio recordings of drumming from other woodpeckers. This faux territorial invasion sparked an aggressive drumming response from the birds, which were then captured and euthanized to have their recent brain activity analyzed. Sure enough, the same regions identified by earlier lab tests had been activated in the drummers.

The brains of bird vocalists and drummers evolved separately, but the similarity of the analyzed regions hints at a common origin. “It suggests that there are common themes about how you develop these complex behaviors,” says Bradley Colquitt, a biologist at the University of California, Santa Cruz who was not involved in the study. The neural circuitry formed by these nuclei most likely developed from an ancestral circuit controlling movement, Colquitt says.

“Birdsong is basically the brain controlling muscles in a vocal organ called the syrinx,” Fuxjager says. These sophisticated movements are not unlike the swift head-and-neck motions involved in drumming.

Whether drumming is learned like birdsong remains an open question that the team is now exploring. Future work will also look at how woodpeckers’ brains are wired, how these nuclei control drumming and how the brain regions’ role in drumming evolved across woodpecker species, Fuxjager says.

This new study “uncovers another species that we can add to our comparative efforts” to better understand how complex behaviors evolve, Colquitt says. “It is a preview into potentially exciting evolutionary neurobiology.” Now that woodpeckers have joined the band of important musical birds, it looks like the drummers may soon get their chance to shine.

NASA’s Artemis I mission sets the stage for our return to the moon

When Artemis I blasts off into the early morning sky over Florida, it may launch a new era of lunar science and exploration with it.

The NASA mission, scheduled to launch in the next two weeks, is the first of three planned flights aimed at landing humans on the moon for the first time since 1972. No astronauts will fly on the upcoming mission. But the flight marks the first test of the technology — the rocket, the spacesuits, the watery return to Earth — that will ultimately take people, including the first woman and the first astronaut of color, to the lunar surface.
The test includes the first flight of NASA’s Space Launch System, or SLS, and its Orion spacecraft, a rocket and crew capsule that have been decades in the making. These craft have been delayed, blown through their budgets and been threatened with cancellation more than once. Even within the spaceflight community, a lot of people feared they would never fly.

To see a human-capable moon rocket finally on the launchpad is “pretty astonishing,” says Casey Dreier, a Seattle-based space policy expert at the Planetary Society. “This is a reality that most of us alive on Earth today have never experienced.”

And if the Artemis program works, opportunities for science will follow.

“Because humans have to come back, alive, you have a huge opportunity to bring samples back with you,” Dreier says. Sending human astronauts may be a wedge to open the door for pure learning.

The launch
Artemis I is slated to lift off on August 29 at 8:33 a.m. EDT. The SLS rocket will lift Orion into space, where the crew capsule will separate from the rocket and continue to an orbit around the moon. After circling the moon for about two weeks, Orion will slingshot back to Earth and splash down in the Pacific Ocean off the coast of San Diego. The whole mission will last about 42 days.

Orion will stay in space longer than any other human-rated spacecraft has without docking to another spaceship, like the International Space Station. At its closest approach, the spacecraft will fly about 100 kilometers above the lunar surface. It will also go up to 64,000 kilometers past the moon, farther from Earth than any spacecraft built for humans. The previous record, set by Apollo 13 in 1970, was 16,000 kilometers beyond the far side of the moon.
The main goal of the mission is to prove that everything works. That includes Orion’s heat shield, which will need to protect astronauts as the capsule comes screaming through Earth’s atmosphere at 40,000 kilometers per hour and heats up to more than 2700° Celsius on its return trip. It also includes the procedure for retrieving the capsule and its crew and cargo after splashdown.

Even though it has no astronauts, the mission won’t be flying empty. Just beneath the Orion capsule are 10 CubeSats, small, simple spacecraft each about the size of a shoebox. After Orion separates from the SLS rocket, those CubeSats will go their separate ways to study the moon, the radiation environment in space and the effects of that radiation on organisms like yeast. One CubeSat will unfurl a solar sail and take off to explore a near-Earth asteroid (SN: 8/26/11).

The “crew”
Inside the Orion capsule ride three humanoid passengers. In the commander’s seat is faux astronaut Moonikin Campos, named for Arturo Campos, a NASA engineer who played a key role in returning the Apollo 13 moon mission safely to Earth after its in-flight disaster in 1970. The “moonikin” — a mashup of moon and manikin — is based on a firefighter training rescue manikin, says NASA engineer Dustin Gohmert. Moonikin Campos will be wearing the new flight suit that was designed for the Artemis missions.
The spacesuit is like a personalized spacecraft, says Gohmert, of the Johnson Space Center in Houston, Texas. It’s meant to be worn during takeoff, landing and any time there is an emergency in the cabin. The suit may look familiar to anyone who watched space shuttle launches, Gohmert says, because it does a very similar job: “It’s an orange suit that acts like a balloon that’s shaped like your body.”

The main difference is that the Orion suit, plus the accompanying helmet, seat and connection to the Orion spacecraft itself, are designed to keep a crew member alive for up to six days, the time it could take to get back to Earth if something goes wrong in deep space. Astronauts visiting the International Space Station, by contrast, were never more than a few hours from Earth.

To help make that week tolerable, each suit will be custom fit to the astronaut. “I’d like to say the word ‘comfort,’ but that’s a difficult word to use,” Gohmert says. “Nothing will be comfortable about six days in a spacesuit, no matter what you do.”

The suit and spacecraft will provide the astronauts with oxygen and scrub the astronauts’ air of carbon dioxide. The suit will also have a tube for the astronauts to eat liquid food and a way for them to collect urine and feces, although Moonikin Campos won’t test those aspects. He will be equipped with radiation sensors, while his seat will have sensors to detect acceleration and vibration throughout the mission.
The suit, helmet and seat all take safety lessons from the space shuttle Columbia disaster, Gohmert says (SN: 9/22/2003). A junior engineer at the time, Gohmert worked on the suits the Columbia astronauts wore and saw the seven-member crew off to the launchpad. “It was a pivotal point for all of us, of course, who were there at the time,” he says. “If we didn’t take lessons from that, we wouldn’t be doing them justice.”

Moonikin Campos will be accompanied by a pair of mockup female torsos named Helga and Zohar. Their mission is to report back on space risks that are unique to female bodies, which have never been near the moon. NASA plans to send a woman on the first crewed Artemis flight, and women have different cancer risks from space radiation than men.
The two torsos are figures used in medicine called anthropomorphic phantoms, which are made from materials that simulate human bone, tissue and organs. “They are in principle identical twins,” said physicist Thomas Berger of the German Aerospace Center in Cologne in a briefing on August 17. But Zohar — whose name means “light” or “radiance” in Hebrew — will wear a radiation protection vest provided by the Israel Space Agency and the private company StemRad, based in Tampa, Fla.

The vest is made of a polymer designed to deflect protons that the sun releases during solar storms and has more shielding over radiation-sensitive organs like breasts and ovaries. Each phantom will also carry more than 6,000 small radiation detectors to build a 3-D picture of the dose of charged particles a female astronaut might receive on a trip to the moon and back. Comparing the radiation levels each phantom receives will help refine the vest’s design for future astronauts.

Orion will also carry two other nonhuman passengers — the British stop motion television character Shaun the sheep and Snoopy, who will serve as an indicator of zero gravity.

The past and the future
SLS and Orion have had a checkered history. The program goes back to 2004, when President George W. Bush proposed sending astronauts to the moon and then to Mars. In 2010, President Barack Obama canceled that plan, and then in 2017 President Donald Trump directed NASA to retrain its sights on the moon.

All the while, Congress continued to fund the development of the SLS rocket. Originally, SLS was supposed to cost $6 billion and fly in 2016. It has so far cost $23 billion on the eve of its launch in 2022.

“The rhetoric has flip-flopped a bunch,” Dreier says, as political leaders kept changing their vision for NASA’s direction. “But if you look at the actual programs, very little changed. … The whole time, the money was going to a moon rocket and a moon capsule.”

The next Artemis mission, Artemis II, is scheduled to launch in 2024 and take astronauts — real, live, human astronauts — around the moon but not to its surface.

Artemis III will be the moon landing mission. On August 19, NASA announced 13 candidate landing regions, all near the moon’s south pole, an intriguing spot that has never been visited by humans (SN: 11/11/18). That mission is scheduled to launch in 2025, but there are still a lot of untested elements. Those include the actual lander, which will be built by SpaceX.

There are still a lot of things that can go wrong and a long way to go. But the Artemis I launch is an optimistic dawn for lunar science nevertheless. “The whole [human spaceflight] system has all been shifting to point at the moon,” Dreier says. “I think that’s profoundly exciting. There’s going to be really interesting lessons that happen no matter what comes out of this.”

‘Chameleon’ forces remain elusive in a new dark energy experiment

A chameleon-like force that shifts its nature based on its environment could explain a major physics quandary: how the mysterious substance called dark energy is compelling the cosmos to expand faster and faster. But a new experiment casts doubt on some chameleon theories, researchers report August 25 in Nature Physics.

The chameleon force would be a fifth type of force beyond the basic four: gravitational, strong, weak and electromagnetic. And like a chameleon changing its colors, the hypothetical fifth force would morph depending on the density of its surroundings. In dense environments like Earth, this fifth force would be feeble, camouflaging its effects. In the sparseness of space, the force would be stronger and long-ranged.
This force would result from a chameleon field — an addition to the known fields in physics, such as electric, magnetic and gravitational fields. A chameleon field with these morphing properties could drive the accelerating expansion of the universe without disagreeing with measurements on Earth.

But it’s a challenge to suss out such a changeling force. On Earth, says astrophysicist Jianhua He of Nanjing University in China, “it’s very, very tiny. That’s the most difficult part.”

So He and colleagues designed a detector to search for a subtle fifth force. A wheel with plastic films attached spins past another film sitting on a magnetically levitated piece of graphite. If a chameleon force really exists, the films spinning by would cause a periodic force on the levitating plastic, pulling it up and down. (Gravity also acts this way, but thanks to the device’s design, it should be much weaker than a chameleon force.)

The team was able to rule out a category of chameleon theories. In the future, the researchers hope to improve their results by chilling their device to allow for more sensitive measurements.

7-million-year-old limb fossils may be from the earliest known hominid

In 2001, researchers unearthed a partial fossil leg bone and two forearm bones in the central African nation of Chad. Those fossils come from the earliest known hominid, which lived around 7 million years ago, and reveal that the creature walked upright both on the ground and in the trees, a new study proposes.

But a lively debate surrounds the fossils, concerning whether they actually belong to the hominid species, known as Sahelanthropus tchadensis, or to an ancient ape, and to what extent either species could have adopted a two-legged gait. These have become vexing questions as scientists increasingly suspect that ape and hominid species evolved a variety of ways to walk upright, some more efficient than others, around 7 million years ago.
Since its discovery, the leg bone has also triggered competing accusations of scientific misconduct and an official investigation by the French government–funded research organization CNRS in Paris.

Previously, skull, jaw and tooth finds uncovered at the Chad site in 2001 and 2004 were classified as remnants of S. tchadensis (SN: 4/6/05). The finds are the only other fossils attributed to the species, though some researchers have also since suggested that those fossils represent an ancient ape instead.

Analyses of the three limb bones show that they belong to the previously identified Sahelanthropus species, say paleontologists Guillaume Daver and Franck Guy, both of the University of Poitiers in France, and their colleagues. And internal and external features of the leg bone indicate that Sahelanthropus walked upright, the scientists report August 24 in Nature. Shapes and structures of the two forearm bones suggest that the hominid moved on two legs through trees while grasping branches with its hands, the team says.

“The Chadian species has a set of anatomical features that clearly indicate that our oldest known [hominid] representative [walked] on the ground and in the trees,” Guy says. It’s hard to tell how efficiently or how fast Sahelanthropus moved on two legs, he adds.

Guy’s team studied 3-D digital models of the fossils derived from CT scans. The leg bone was compared with fossils of ancient apes and other hominids and with modern apes and humans. Traits including thickening of the leg bone’s tough outer layer at key points and the presence of an internal bony projection near the hip joint signal an upright stance, the scientists say.

Fossils from the African site, including the three limb bones, suggest that Sahelanthropus was the earliest known hominid, agrees paleoanthropologist Kristian Carlson of the University of Southern California in Los Angeles, who did not participate in the new study. But exactly how it moved while upright remains unknown, he says. Sahelanthropus exhibits a mix of upper leg and forearm traits that differs from those of living apes and humans, suggesting it adopted a novel posture and limb movements while walking.

Whatever stance Sahelanthropus assumed, it probably resembled that of two other early hominids, roughly 6-million-year-old Orrorin tugenensis and more than 5-million-year-old Ardipithecus kadabba, says paleoanthropologist Yohannes Haile-Selassie, director of the Institute of Human Origins at Arizona State University in Tempe (SN: 9/11/04; SN: 3/3/04). Walking abilities of those hominids remain poorly understood due to limited fossils — a partial leg bone for O. tugenensis and a toe bone for the Ardipithecus species.

Haile-Selassie regards all three hominids as part of a single genus that evolved from around 7 million to 5 million years ago. On that issue, “the debate is open, even between members of our team,” Guy says.

Another debate concerns the upper leg’s internal bony projection that the researchers cite as crucial for standing upright. That trait sometimes appears in modern African apes and occasionally is absent in humans, paleoanthropologist Marine Cazenave of the American Museum of Natural History in New York City and colleagues report in the June Journal of Human Evolution. The presence of this bony growth does not definitively show that Sahelanthropus walked upright, Cazenave says.

Other researchers contend that the leg bone most likely comes from an ancient ape — not a hominid — that may have occasionally walked upright. Shape measurements, including curvature of the fossil’s shaft, closely resemble those of modern chimps’ upper leg bones, University of Poitiers paleoanthropologist Roberto Macchiarelli and colleagues reported in December 2020 in the Journal of Human Evolution.

“There may have been ancient apes that had distinctive types of [upright movement] unlike any living apes, including humans,” says paleoanthropologist Bernard Wood of George Washington University in Washington, D.C., who was a coauthor of the 2020 study.

Here is where charges of scientific misconduct come into play. The 2020 study was based on measurements of the Sahelanthropus leg fossil taken in 2004 by a University of Poitiers graduate student conducting a project on how fossilization affects bones.

That student, Aude Bergeret-Medina, was given access to fossils from the Sahelanthropus site that Daver and Guy’s team had tagged as neither hominid nor, more generally, as primate. She noted that one specimen — the leg bone — looked like it belonged to a primate, possibly an ape. Macchiarelli confirmed her observation. Plans for Bergeret-Medina to cut open the bone to study its mineral content were halted.

Macchiarelli informed his university and CNRS of the fossil’s identity. He spent the next 16 years, he says, sending repeated complaints to those institutions that the Sahelanthropus discoverers were violating codes of scientific conduct by not providing information about the leg bone in scientific papers or talks.

Then, CNRS launched an investigation of possible misconduct by Macchiarelli himself when the 2020 study appeared before the Sahelanthropus team published findings on the leg bone in its possession. No ruling has been made yet.

In supplementary information published with the new study, Guy and colleagues write that they identified the forearm bones among stored fossils after Macchiarelli brought the leg bone’s identity to their attention. Further excavations in Chad were conducted before launching a detailed study of the three limb fossils in 2017, the team says.

But the Sahelanthropus team does not cite Bergeret-Medina — now the curator of the Muséum d’Histoire Naturelle Jacques de La Comble in Autun, France — by name for her role in the leg bone’s identification. The investigators write that “a master’s student in taphonomy” received various fossils for a research internship in early 2004 before those finds had been carefully examined by senior scientists. The student, “seeking expertise,” gave the leg fossil to Macchiarelli who identified it as a hominid, Daver and colleagues say.

That’s incorrect, Macchiarelli contends. Bergeret-Medina initially identified the fossil as a primate’s upper leg bone followed by his confirmation of her observation. No claim was made that the fossil came from a hominid, he says. But without Bergeret-Medina’s insightful fossil observation, the new study would never have happened, Macchiarelli asserts.

A new seasoning smells like meat thanks to sugar — and mealworms

A spoonful of sugar may help the mealworms go down.

Adding sugars to powdered, cooked mealworms creates a seasoning with an appetizing “meatlike” odor, researchers report August 24 at the American Chemical Society fall meeting in Chicago.

Some insects have been found to be an environmentally friendly alternative to other animal protein because they require less land and water to raise (SN: 5/11/19). But many people in the United States and other Western countries, where insects aren’t eaten widely, generally find the idea of chomping down on bugs unappetizing.
“There aren’t a lot of people ready to fry up a whole skillet of crickets and eat them fresh,” says Julie Lesnik, a biological anthropologist at Wayne State University in Detroit who wasn’t involved in the new research. Finding out how to make insect-based foods more appealing could be key to making them more mainstream.

And one successful insect-based product could have a snowball effect for similar food. “It’s really great that this research is happening, because at any point this might be the thing that people figure out and then it explodes,” says Brenden Campbell, an insect agriculturist based in Eugene, Ore. He has studied mealworms and created a company called Planet Bugs to, in part, make insect-based food products.

In a previous study, chemist In Hee Cho of Wonkwang University in South Korea and colleagues analyzed the odors given off by mealworms that were steamed, roasted or deep-fried. Steamed mealworms produced a sweet smell, like corn, while roasted and fried mealworms released chemicals more similar to meat and seafood.

In their latest work, the team then keyed in on what combinations of water, sugars and cooking time produced a particularly meaty smell, and tested these concoctions with volunteers to figure out which smelled the most appealing.

Using insects ground up or in seasonings, like Cho’s team did, could help people get past their hesitations about eating whole bugs, says Amy Wright, who has written a book on eating bugs. (She, for one, has no qualms. A literature professor at Austin Peay State University in Clarksville, Tenn., Wright used to keep mealworms in her apartment, which she would use in sandwiches and guacamole.)

“There are plenty of things that are disgusting to us, but we have engineered around it,” Lesnik says. “We’re just seeing insects being treated like any other food, and yeah, we’re talking aroma … but that’s what the engineers of Doritos are doing.”

50 years ago, genes eluded electron microscopes

Molecular biologists can now visualize the larger structures of the cell, such as the nucleus and chromosomes, under the powerful electron microscope. But they have not been able to obtain images of genes (DNA) on the chromosomes. Nor have they been able to see RNA … or the intricate details of cell membranes, enzymes and viruses.

Update
Electron m­icroscopes have become much more powerful over the last 50 years. For instance, in 1981, biophysicist Jacques D­ubochet discovered that tiny biological structures super­cooled with ethane could be observed in their natural state under an electron microscope. That finding paved the way for cryo-electron micro­scopy, which scientists use to visualize proteins, viruses and bacteria at the molecular level (SN: 10/28/17, p. 6). Capturing detailed images of genes remains elusive, but scientists are inching closer. In 2021, researchers reported using an electron microscope and the molecular scissors CRISPR/Cas9 to visualize proteins transcribing DNA instructions for two genes into RNA.

Sleep deprivation may make people less generous

Lack of sleep has been linked to heart disease, poor mood and loneliness (SN: 11/15/16). Being tired could also make us less generous, researchers report August 23 in PLOS Biology.

The hour of sleep lost in the switch over to Daylight Savings Time every spring appears to reduce people’s tendency to help others, the researchers found in one of three experiments testing the link between sleep loss and generosity. Specifically, they showed that average donations to one U.S.-based nonprofit organization dropped by around 10 percent in the workweek after the time switch compared with four weeks before and after the change. In Arizona and Hawaii, states that do not observe Daylight Savings Time, donations remained unchanged.
With over half of the people living in parts of the developed world reporting that they rarely get enough sleep during the workweek, the finding has implications beyond the week we spring forward, the researchers say.

“Lack of sleep shapes the social experiences we have [and] the kinds of societies we live in,” says neuroscientist Eti Ben Simon of the University of California, Berkeley.

To test the link between sleep loss and generosity, Ben Simon and her team first brought 23 young adults into the lab for two nights. The participants slept through one night and stayed awake for another night.

In the mornings, participants completed a standardized altruism questionnaire rating their likelihood of helping strangers or acquaintances in various scenarios. For instance, participants rated on a scale from 1 to 5, with 1 for least likely to help and 5 for most likely, whether they would give up their seat on a bus to a stranger or offer a ride to a coworker in need. Participants never read the same scenario more than once. Roughly 80 percent of participants showed less likelihood of helping others when sleep-deprived than when rested.

The researchers then observed participants’ brain activity in a functional MRI machine, comparing each participant’s neural activity in a rested versus sleep-deprived state. That showed that sleep deprivation reduced activity in a network of brain regions linked to the ability to empathize with others.

In another experiment, the researchers recruited 136 participants online and had them keep a sleep log for four nights. Each participant then completed subsets of the altruism questionnaire before 1 p.m. the next day. The researchers found that the more time participants spent awake in bed, a measure of poor sleep, the lower their altruism scores. That drop in altruism held true both when comparing individuals to themselves and when averaging scores across the group.

In the final experiment focused on Daylight Savings Time, the researchers looked at charitable donations from 2001 to 2016 to Donors Choose, a nonprofit that raises money for school projects across the United States. When the team excluded Hawaii and Arizona, as well as outliers like very large donations, more than 3.4 million donations remained. In the workweek following the time change, total donations, which typically averaged roughly $82 per day, dropped to about $73 per day, Ben Simon says.

There’s always a possibility that some other variable besides sleep is causing this dip in generosity, says behavioral economist David Dickinson of Appalachian State University in Boone, N.C. But this “triple methodology approach” enabled the researchers to draw a convincing line from changes to the brain that appear during sleep deprivation to real-world behavior. “This puts a more comprehensive story on how inefficient sleep affects decisions in this domain of helping others,” he says.

Chronic sleep deprivation in the modern world is a serious problem, Ben Simon says (SN: 3/1/19). But unlike many other large-scale problems — think climate change or political polarization — this one has a ready solution. “If you think about promoting sleep and letting people get the sleep they need, what an impact that could have on the societies we live in.”

A shot of immune proteins may protect against malaria for months

A single shot that could provide months-long protection against malaria has proven effective and safe in a small, early clinical trial of adults.

The shot, which contains monoclonal antibodies, would primarily be intended for infants and children in countries with the most malaria transmission, the team who conducted the trial says. These young children have the highest risk of dying from severe malaria.

In the clinical trial, 15 of 17 participants who received the monoclonal antibodies did not become infected after being exposed to mosquitoes with malaria in the lab, the researchers report in the Aug. 4 New England Journal of Medicine. All six people who did not receive the medicine developed infections.
The clinical trial tested different doses and delivered the medicine intravenously or as a shot. Based on a computer model of how the medicine is taken up, distributed and then cleared by the body, the researchers estimate that one shot may protect against malaria for six months.

“What we’ve always been looking for is some sort of intervention that will prevent infection reliably and for as long a time as possible,” says Miriam Laufer, a pediatric infectious disease doctor and director of the Malaria Research Program at the University of Maryland School of Medicine in Baltimore.

Ideally, Laufer says, that would be a highly effective vaccine that provides years and years of protection. A new malaria vaccine has recently become available, but it is only modestly protective against the disease, and that protection wanes rapidly (SN: 12/22/21). The vaccine requires four shots.

Monoclonal antibodies could provide an option that requires only one shot, once a year. It will take more research to see how well the antibodies work against malaria outside of the laboratory and how cost-effective the shot is.

The monoclonal antibodies shot wouldn’t exclude the need for other prevention strategies, says Laufer, who was not involved in the new study. But it could be “one of the easier interventions in terms of minimal contact with the health care system, with good benefit.”

What’s appealing, she says, “is the possibility that you could give kids, even the youngest kids, an injection [of] premade antibodies that could last for six months or longer and protect them throughout the rainy season.” That once-a-season shot would be helpful in countries in West Africa, where malaria transmission only occurs during the rainy season.

Malaria sickened an estimated 241 million people and killed 627,000 worldwide in 2020. Most of those deaths occurred in sub-Saharan Africa in children younger than 5. These littlest kids haven’t had the chance to develop immunity to the disease and are more susceptible to dying if severe malaria develops.

Reducing the spread of malaria includes measures to control mosquitoes, such as using insecticide-treated nets over beds or spraying to kill mosquitoes indoors, as well as preventing infections, such as taking antimalarial drugs at regular intervals. In October 2021, the World Health Organization also recommended the new vaccine, which in clinical trials reduced cases of malaria and severe malaria by 36 percent after four years of follow-up.

Monoclonal antibodies are a laboratory-made version of antibodies, the proteins that the immune system produces in response to a vaccine or natural infection. Monoclonal means that it contains clones, or copies, of one particular antibody.

The antibody evaluated in the clinical trial attaches to a protein on the surface of sporozoites — the form of the malaria parasite that enters the body after an infected mosquito bites — and stops the parasites from infecting the liver.

The new monoclonal antibody has improvements over an earlier version developed by the same research team. The new version binds more strongly to the targeted malaria parasite protein. It also has a tweak that keeps it from degrading too quickly in the body. This boosts its half-life in the blood (the time it takes for half of the medicine to degrade) to 56 days, almost three times that of its predecessor.

Two clinical trials are planned to assess how well the medicine protects children in places where malaria is spreading. One trial in Mali, where malaria transmission is seasonal, will study the shot’s efficacy over seven months. Another trial in Kenya, among the countries in East Africa where malaria spreads year-round, will assess how well the shot works while following the children for a year. Those studies will also help to determine the best dose for children.