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The United States is poised to take a powerful economic hit from climate change over the next century. Heat waves, wildfires, extreme weather events and rising sea levels could cost the country hundreds of billions of dollars in lost labor, reduced crop yields, health problems and crumbling infrastructure.

A report authored by hundreds of U.S. climate scientists from 13 federal agencies presents a stark picture of the country’s fate due to climate change. The Fourth National Climate Assessment, released November 23, predicts the U.S. economy will shrink by as much as 10 percent by the end of the century if global warming continues apace.
A separate report released November 27 by the United Nations Environment Programme reveals that in 2017, global emissions of carbon dioxide — a major driver of warming — rose for the first time in three years. That suggests that the nations that promised to curb emissions as part of the historic 2015 Paris agreement are falling short (SN: 1/9/16, p. 6).

It’s unclear what effect, if any, the reports will have on the U.S. government’s strategy on dealing with climate change and its consequences. President Donald Trump has previously announced he would withdraw the United States from the Paris agreement (SN Online: 6/1/17). And on November 26, Trump told reporters that he had read “some of” his scientists’ report. “It’s fine,” he said. But when it comes to the dire predictions of economic losses, he added, “I don’t believe it.”

The National Climate Assessments are mandated by Congress and produced every four years, focusing on the risks of climate change specifically to the United States. What’s different about the new report compared with previous editions is its precision about the risks to different parts of the U.S. economy, putting a price tag on the potential losses in agriculture, trade and energy generation.

To put a dollar value on bad air quality or worsening heat waves, for instance, scientists try to assess the measurable impacts of those issues — for example, the number of days of work or school missed, or the number of doctors’ visits triggered (SN Online: 10/14/18).
The more-than-1,600-page report includes detailed examinations of the effects of climate change on the country’s different regions. People living in the northeastern United States, for example, will be among the hardest hit by deaths due to poor air quality and temperature extremes by the end of the century. Labor losses in the southeastern United States are the highest of all regions, as are projected damages to roads and bridges, the report found.

Meanwhile, the Midwest will see the highest increase in premature deaths from increased amounts of ozone. And the Southwest, which includes California in these analyses, will suffer from extreme heat, drought and an increase in future cases of the mosquito-borne West Nile virus.

The report estimates that cumulatively the country will spend $23 billion responding to wildfires by the end of the century, even if greenhouse gas emissions are modestly reduced. The Southwest will bear the brunt of that impact, spending $13 billion dollars.

The report also details the many ways in which climate change is already hurting the country economically. For example, three storms that made landfall during the 2017 Atlantic hurricane season — Harvey, Irma and Maria — together cost the United States at least $265 billion, according to the National Oceanic and Atmospheric Administration.

By continuing on its current trajectory of greenhouse gas emissions, the “business-as-usual” scenario, the United States will see the greatest losses, the assessments concludes. However, the report also considers climate impacts in an alternate future, in which the world has taken modest actions to curb greenhouse emissions, including using more carbon-neutral fuels and the growth of technological innovations to remove carbon dioxide from the atmosphere (SN Online: 10/20/18).

Earth’s heart may have a secret chamber. The planet’s inner core isn’t just a solid ball of nickel and iron, researchers say, but contains two layers of its own: a distinct central region nestled within an outer shell.

Scientists say they have confirmed the existence of this innermost inner core using a type of previously undescribed seismic wave that not only travels through Earth’s core but also bounces back and forth through the interior, collecting invaluable data about the core’s structure along the way.
Focusing on earthquakes of magnitude 6 or larger that struck in the last decade, the researchers combined data on these quakes that were collected at seismic stations around the world. Combining these signals made it possible to detect even very faint reflections of the seismic waves. Of the 200 or so quakes analyzed, 16 events spawned seismic waves that detectably bounced through the inner core multiple times.

The origin, structure and fate of Earth’s core is of intense interest because the core generates the planet’s magnetic field, which shields the Earth from charged particles ejected by the sun and helps keep the planet’s denizens safe from too much radiation.

“Understanding how the magnetic field evolves is extremely important for the life on Earth’s surface,” says Hrvoje Tkalčić, a seismologist at the Australian National University in Canberra.

The entire core, about 6,600 kilometers across, consists of two main parts: a liquid outer core and a solid inner core (SN: 1/23/23). As iron-rich fluid circulates in the outer core, some of the material cools and crystallizes, sinking to form a solid center. That interplay generates Earth’s magnetic field.

When this swirling dance first began isn’t certain, but some studies suggest it was as recent as 565 million years ago, just a fraction of Earth’s 4.6-billion-year-long life span (SN: 1/28/19). That dance has faltered from time to time, its stuttering steps preserved in tiny magnetic grains in rocks. These data suggest the planet’s magnetic poles have flip-flopped many times over the years, temporarily weakening the magnetic field (SN: 2/18/21). As more and more crystals cool, the dance will eventually slow and stop, shutting off the planet’s magnetic field millions or billions of years from now.

Different types and structures of minerals, as well as different amounts of liquid in the subsurface, can change the speed of seismic waves traveling through Earth, offering clues to the makeup of the interior. In 2002, researchers noted that seismic waves traveling through the innermost part of Earth move slightly slower in one direction relative to the planet’s poles than in other directions. That suggests there’s some oddity there — a difference in crystal structure, perhaps. That hidden heart, the team suggested, might be a kind of fossil: a long-preserved remnant of the core’s early formation.

Since that observation, Tkalčić and others have pored over seismic data, finding independent lines of evidence that help support the idea of an innermost inner core. The reverberating seismic waves, described February 21 in Nature Communications, also show a slowdown, and are the strongest evidence yet that this hidden heart exists.
Using that seismic data, Tkalčić and seismologist Thanh-Son Phạm, also of the Australian National University, estimate that this inner heart is roughly 600 kilometers across, or about half the diameter of the full inner core. And the pair was able to assess the direction of the slowest waves at about 50 degrees relative to the Earth’s rotation axis, providing more insight into the region.

The exact source of the wave slowdown isn’t clear, Tkalčić says. The phenomenon might be related to the structure of the iron crystals, which may be packed together differently farther into the center. Or it could be from a different crystal alignment caused by some long-ago global event that changed how inner core crystals solidified out of the outer core.

The inner core holds many other mysteries too. Lighter elements present in small amounts in the core — hydrogen, carbon, oxygen — may flow around the solid iron in a liquidlike “superionic” state, further complicating the seismic picture (SN: 2/9/22).

By identifying and reporting seismic waves that bounced back and forth through the planet’s interior multiple times, the researchers have made an invaluable contribution that will help researchers study the core in new ways, says seismologist Paul Richards of Columbia University’s Lamont-Doherty Earth Observatory in Palisades, N.Y.

Still, the team’s interpretation of the inner core’s structure from those waves “is probably more iffy,” says Richards, who wasn’t involved in the work.

One reason for this uncertainty is that as the waves bounce back and forth, they can become weaker and more difficult to see in the data, he says. “Many further observations will help decide” what these new data can reveal about the heart of the planet.

Future therapy patients may spend a lot more time exploring virtual environments than sitting on sofas.

In a clinical trial of a new virtual reality treatment for fear of heights, participants reported being much less afraid after using the program for just two weeks. Unlike other VR therapies, which required that a real-life therapist guide patients through treatment, the new system uses an animated avatar to coach patients through ascending a virtual high-rise. This kind of fully automated counseling system, described online July 11 in the Lancet Psychiatry, may make psychological treatments for phobias and other disorders far more accessible.
This is “a huge step forward” for therapeutic VR, says Jennifer Hames, a clinical psychologist at the University of Notre Dame in Indiana, who wasn’t involved in the work. By bringing expert therapy out of the counselor’s office and into primary care clinics — or even people’s homes — the new system could help those who aren’t comfortable or don’t have the means to speak with a therapist face-to-face, she says.
Users immerse themselves in this virtual reality program using a VR headset, handheld controllers and headphones. An animated counselor guides the user through a virtual 10-story office complex, where upper floors overlook a ground-level atrium. On every floor, the user performs tasks designed to test their fear responses and help them learn that they’re safer than they might think. The tasks start out relatively easy — like standing close to a drop-off where a safety barrier gradually lowers — and progress to more difficult challenges — like riding a moving platform out into the open space over the atrium.
By working through these activities, “the person builds up memories that being around heights is safe, and this counteracts the old fear beliefs,” says Daniel Freeman, a clinical psychologist at the University of Oxford.

To test their program’s effectiveness, Freeman and colleagues recruited 100 adult volunteers who were moderately to severely afraid of heights. The researchers randomly assigned 49 people to undergo VR treatment, which involved using the program for about six 30-minute sessions over two weeks, while the other 51 participants received no treatment.

Participants filled out a questionnaire that rated their fear of heights from 16 to 80 (with 80 being most severe), before treatment, immediately afterward, and two weeks later. People who underwent VR treatment dropped about 25 points on average on the questionnaire’s scale, while patients who received no treatment remained stable. Participants who used the VR program found they “could go to places that they wouldn’t have imagined possible,” Freeman says, like steep mountains, rope bridges or simply escalators in shopping malls.

“When I’ve always got anxious about an edge, I could feel the adrenaline in my legs, that fight/flight thing; that’s not happening as much now,” one participant said. “I’m still getting a bit of a reaction to it, both in VR and outside as well, but it’s much more brief, and I can then feel my thighs soften up as I’m not bracing up against that edge.”

While the clinical trial results provide strong evidence that the new VR program mitigates fear better than no treatment at all, researchers still need to investigate how VR therapy stacks up against sessions with a therapist, Hames says. And since Freeman’s team only tracked treatment effects up to a couple of weeks after their experiment, it remains to be seen how long the effects of this therapy last — although previous research on therapist-led VR treatment have shown lasting impacts for at least a year.

While fully automated VR therapy may be good news for people who fear heights, it’s not clear how well this type of system could address more complex mental health issues, says Mark Hayward, a clinical psychologist at the University of Sussex in England whose commentary on the study appears in the same issue of the Lancet Psychiatry. Virtual environments may be well suited for helping people who fear everyday situations, like those who suffer from common phobias, social anxiety or paranoia, Hayward says. But when it comes to helping people with more severe symptoms, like psychosis, VR probably won’t stand in for trained therapists any time soon.

“We can’t get carried away and say we can automate all [mental health] treatment,” says Albert Rizzo, a clinical virtual reality developer at the University of Southern California in Playa Vista not involved in the work. But the new standalone system for curbing fear of heights is “an excellent first effort.”

Just a few powerful storms in Antarctica can have an outsized effect on how much snow parts of the southernmost continent get. Those ephemeral storms, preserved in ice cores, might give a skewed view of how quickly the continent’s ice sheet has grown or shrunk over time.

Relatively rare extreme precipitation events are responsible for more than 40 percent of the total annual snowfall across most of the continent — and in some places, as much as 60 percent, researchers report March 22 in Geophysical Research Letters.
Climatologist John Turner of the British Antarctic Survey in Cambridge and his colleagues used regional climate simulations to estimate daily precipitation across the continent from 1979 to 2016. Then, the team zoomed in on 10 locations — representing different climates from the dry interior desert to the often snowy coasts and the open ocean — to determine regional differences in snowfall.

While snowfall amounts vary greatly by location, extreme events packed the biggest wallop along Antarctica’s coasts, especially on the floating ice shelves, the researchers found. For instance, the Amery ice shelf in East Antarctica gets roughly half of its annual precipitation — which typically totals about half a meter of snow — in just 10 days, on average. In 1994, the ice shelf got 44 percent of its entire annual precipitation on a single day in September.

Ice cores aren’t just a window into the past; they are also used to predict the continent’s future in a warming world. So characterizing these coastal regions is crucial for understanding Antarctica’s ice sheet — and its potential future contribution to sea level rise.
Editor’s note: This story was updated April 5, 2019, to correct that the results were reported March 22 (not March 25).

We live in a sea of neutrinos. Every second, trillions of them pass through our bodies. They come from the sun, nuclear reactors, collisions of cosmic rays hitting Earth’s atmosphere, even the Big Bang. Among fundamental particles, only photons are more numerous. Yet because neutrinos barely interact with matter, they are notoriously difficult to detect.

The existence of the neutrino was first proposed in the 1930s and then verified in the 1950s (SN: 2/13/54). Decades later, much about the neutrino — named in part because it has no electric charge — remains a mystery, including how many varieties of neutrinos exist, how much mass they have, where that mass comes from and whether they have any magnetic properties.
These mysteries are at the heart of Ghost Particle by physicist Alan Chodos and science journalist James Riordon. The book is an informative, easy-to-follow introduction to the perplexing particle. Chodos and Riordon guide readers through how the neutrino was discovered, what we know — and don’t know — about it, and the ongoing and future experiments that (fingers crossed) will provide the answers.

It’s not just neutrino physicists who await those answers. Neutrinos, Riordon says, “are incredibly important both for understanding the universe and our existence in it.” Unmasking the neutrino could be key to unlocking the nature of dark matter, for instance. Or it could clear up the universe’s matter conundrum: The Big Bang should have produced equal amounts of matter and antimatter, the oppositely charged counterparts of electrons, protons and so on. When matter and antimatter come into contact, they annihilate each other. So in theory, the universe today should be empty — yet it’s not (SN: 9/22/22). It’s filled with matter and, for some reason, very little antimatter.

Science News spoke with Riordon, a frequent contributor to the magazine, about these puzzles and how neutrinos could act as a tool to observe the cosmos or even see into our own planet. The following conversation has been edited for length and clarity.

SN: In the first chapter, you list eight unanswered questions about neutrinos. Which is the most pressing to answer?

Riordon: Whether they’re their own antiparticles is probably one of the grandest. The proposal that neutrinos are their own antiparticles is an elegant solution to all sorts of problems, including the existence of this residue of matter we live in. Another one is figuring out how neutrinos fit in the standard model [of particle physics]. It’s one of the most successful theories there is, but it can’t explain the fact that neutrinos have mass.
SN: Why is now a good time to write a book about neutrinos?

Riordon: All of these questions about neutrinos are sort of coming to a head right now — the hints that neutrinos may be their own antiparticles, the issues of neutrinos not quite fitting the standard model, whether there are sterile neutrinos [a hypothetical neutrino that is a candidate for dark matter]. In the next few years, a decade or so, there will be a lot of experiments that will [help answer these questions,] and the resolution either way will be exciting.

SN: Neutrinos could also be used to help scientists observe a range of phenomena. What are some of the most interesting questions neutrinos could help with?

Riordon: There are some observations that simply have to be done with neutrinos, that there are no other technological alternatives for. There’s a problem with using light-based telescopes to look back in history. We have this really amazing James Webb Space Telescope that can see really far back in history. But at some point, when you go far enough back, the universe is basically opaque to light; you can’t see into it. Once we narrow down how to detect and how to measure the cosmic neutrino background [neutrinos that formed less than a second after the Big Bang], it will be a way to look back at the very beginning. Other than with gravitational waves, you can’t see back that far with anything else. So it’ll give us sort of a telescope back to the beginning of the universe.

The other thing is, when a supernova happens, all kinds of really cool stuff happens inside, and you can see it with neutrinos because neutrinos come out immediately in a burst. We call it the “cosmic neutrino bomb,” but you can track the supernova as it’s going along. With light, it takes a while for it to get out [of the stellar explosion]. We’re due for a [nearby] supernova. We haven’t had one since 1987. It was the last visible supernova in the sky and was a boon for research. Now that we have neutrino detectors around the world, this next one is going to be even better [for research], even more exciting.

And if we develop better instrumentation, we could use neutrinos to understand what’s going on in the center of the Earth. There’s no other way that you could probe the center of the Earth. We use seismic waves, but the resolution is really low. So we could resolve a lot of questions about what the planet is made of with neutrinos.

SN: Do you have a favorite “character” in the story of neutrinos?

Riordon: I’m certainly very fond of my grandfather Clyde Cowan [he and Frederick Reines were the first physicists to detect neutrinos]. But Reines is a riveting character. He was poetic. He was a singer. He really was this creative force. I mentioned [in the book] that they put this “SNEWS” sign on their detector for “supernova early warning system,” which sort of echoed the ballistic missile early warning systems at the time [during the Cold War]. That’s so ripe.

When you’re stressed and anxious, you might feel your heart race. Is your heart racing because you’re afraid? Or does your speeding heart itself contribute to your anxiety? Both could be true, a new study in mice suggests.

By artificially increasing the heart rates of mice, scientists were able to increase anxiety-like behaviors — ones that the team then calmed by turning off a particular part of the brain. The study, published in the March 9 Nature, shows that in high-risk contexts, a racing heart could go to your head and increase anxiety. The findings could offer a new angle for studying and, potentially, treating anxiety disorders.
The idea that body sensations might contribute to emotions in the brain goes back at least to one of the founders of psychology, William James, says Karl Deisseroth, a neuroscientist at Stanford University. In James’ 1890 book The Principles of Psychology, he put forward the idea that emotion follows what the body experiences. “We feel sorry because we cry, angry because we strike, afraid because we tremble,” James wrote.

The brain certainly can sense internal body signals, a phenomenon called interoception. But whether those sensations — like a racing heart — can contribute to emotion is difficult to prove, says Anna Beyeler, a neuroscientist at the French National Institute of Health and Medical Research in Bordeaux. She studies brain circuitry related to emotion and wrote a commentary on the new study but was not involved in the research. “I’m sure a lot of people have thought of doing these experiments, but no one really had the tools,” she says.

Deisseroth has spent his career developing those tools. He is one of the scientists who developed optogenetics — a technique that uses viruses to modify the genes of specific cells to respond to bursts of light (SN: 6/18/21; SN: 1/15/10). Scientists can use the flip of a light switch to activate or suppress the activity of those cells.
In the new study, Deisseroth and his colleagues used a light attached to a tiny vest over a mouse’s genetically engineered heart to change the animal’s heart rate. When the light was off, a mouse’s heart pumped at about 600 beats per minute. But when the team turned on a light that flashed at 900 beats per minutes, the mouse’s heartbeat followed suit. “It’s a nice reasonable acceleration, [one a mouse] would encounter in a time of stress or fear,” Deisseroth explains.

When the mice felt their hearts racing, they showed anxiety-like behavior. In risky scenarios — like open areas where a little mouse might be someone’s lunch — the rodents slunk along the walls and lurked in darker corners. When pressing a lever for water that could sometimes be coupled with a mild shock, mice with normal heart rates still pressed without hesitation. But mice with racing hearts decided they’d rather go thirsty.

“Everybody was expecting that, but it’s the first time that it has been clearly demonstrated,” Beyeler says.
The researchers also scanned the animals’ brains to find areas that might be processing the increased heart rate. One of the biggest signals, Deisseroth says, came from the posterior insula (SN: 4/25/16). “The insula was interesting because it’s highly connected with interoceptive circuitry,” he explains. “When we saw that signal, [our] interest was definitely piqued.”

Using more optogenetics, the team reduced activity in the posterior insula, which decreased the mice’s anxiety-like behaviors. The animals’ hearts still raced, but they behaved more normally, spending some time in open areas of mazes and pressing levers for water without fear.
A lot of people are very excited about the work, says Wen Chen, the branch chief of basic medicine research for complementary and integrative health at the National Center for Complementary and Integrative Health in Bethesda, Md. “No matter what kind of meetings I go into, in the last two days, everybody brought up this paper,” says Chen, who wasn’t involved in the research.

The next step, Deisseroth says, is to look at other parts of the body that might affect anxiety. “We can feel it in our gut sometimes, or we can feel it in our neck or shoulders,” he says. Using optogenetics to tense a mouse’s muscles, or give them tummy butterflies, might reveal other pathways that produce fearful or anxiety-like behaviors.

Understanding the link between heart and head could eventually factor into how doctors treat panic and anxiety, Beyeler says. But the path between the lab and the clinic, she notes, is much more convoluted than that of the heart to the head.

An experimental treatment for endometriosis, a painful gynecological disease that affects some 190 million people worldwide, may one day offer new hope for easing symptoms.

Monthly antibody injections reversed telltale signs of endometriosis in monkeys, researchers report February 22 in Science Translational Medicine. The antibody targets IL-8, a molecule that whips up inflammation inside the scattered, sometimes bleeding lesions that mark the disease. After neutralizing IL-8, those hallmark lesions shrink, the team found.

The new treatment is “pretty potent,” says Philippa Saunders, a reproductive scientist at the University of Edinburgh who was not involved with work. The study’s authors haven’t reported a cure, she points out, but their antibody does seem to have an impact. “I think it’s really very promising,” she says.

Many scientists think endometriosis occurs when bits of the uterine lining — the endometrium — slough off during menstruation. Instead of exiting via the vagina, they voyage in the other direction: up through the fallopian tubes. Those bits of tissue then trespass through the body, sprouting lesions where they land. They’ll glom onto the ovaries, fallopian tubes, bladder and other spots outside of the uterus and take on a life of their own, Saunders says.
The lesions can grow nerve cells, form tough nubs of tissue and even bleed during menstrual cycles. They can also kick off chronic bouts of pelvic pain. If you have endometriosis, you can experience “pain when you urinate, pain when you defecate, pain when you have sex, pain when you move around,” Saunders says. People with the disease can also struggle with infertility and depression, she adds. “It’s really nasty.”
Once diagnosed, patients face a dearth of treatment options — there’s no cure, only therapies to alleviate symptoms. Surgery to remove lesions can help, but symptoms often come back.

The disease affects at least 10 percent of girls, women and transgender men in their reproductive years, Saunders says. And people typically suffer for years — about eight on average — before a diagnosis. “Doctors consider menstrual pelvic pain a very common thing,” says Ayako Nishimoto-Kakiuchi, a pharmacologist at Chugai Pharmaceutical Co. Ltd. in Tokyo. Endometriosis “is underestimated in the clinic,” she says. “I strongly believe that this disease has been understudied.”

Hormonal drugs that stop ovulation and menstruation can also offer relief, says Serdar Bulun, a reproductive endocrinologist at Northwestern University Feinberg School of Medicine in Chicago not involved with the new study. But those drugs come with side effects and aren’t ideal for people trying to become pregnant. “I see these patients day in and day out,” he says. “I see how much they suffer, and I feel like we are not doing enough.”

Nishimoto-Kakiuchi’s team engineered an antibody that grabs onto the inflammatory factor IL-8, a protein that scientists have previously fingered as one potential culprit in the disease. The antibody acts like a garbage collector, Nishimoto-Kakiuchi says. It grabs IL-8, delivers it to the cell’s waste disposal machinery, and then heads out to snare more IL-8.

The team tested the antibody in cynomolgus monkeys that were surgically modified to have the disease. (Endometriosis rarely shows up spontaneously in these monkeys, the scientists discovered previously after screening more than 600 females.) The team treated 11 monkeys with the antibody injection once a month for six months. In these animals, lesions shriveled and the adhesive tissue that glues them to the body thinned out, too. Before this study, Nishimoto-Kakiuchi says, the team didn’t think such signs of endometriosis were reversible.
Her company has now started a Phase I clinical trial to test the safety of therapy in humans. The treatment is one of several endometriosis therapies scientists are testing (SN: 7/19/19) . Other trials will test new hormonal drugs, robot-assisted surgery and behavioral interventions.

Doctors need new options to help people with the disease, Saunders says. “There’s a huge unmet clinical need.”

For generations of dogs, home is the radioactive remains of the Chernobyl Nuclear Power Plant.

In the first genetic analysis of these animals, scientists have discovered that dogs living in the power plant industrial area are genetically distinct from dogs living farther away.

Though the team could distinguish between dog populations, the researchers did not pinpoint radiation as the reason for any genetic differences. But future studies that build on the findings, reported March 3 in Science Advances, may help uncover how radioactive environments leave their mark on animal genomes.
That could have implications for other nuclear disasters and even human space travel, says Timothy Mousseau, an evolutionary ecologist at the University of South Carolina in Columbia. “We have high hopes that what we learn from these dogs … will be of use for understanding human exposures in the future,” he says.

Since his first trip in 1999, Mousseau has stopped counting how many times he’s been to Chernobyl. “I lost track after we hit about 50 visits.”

He first encountered Chernobyl’s semi-feral dogs in 2017, on a trip with the Clean Futures Fund+, an organization that provides veterinary care to the animals. Not much is known about how local dogs survived after the nuclear accident. In 1986, an explosion at one of the power plant’s reactors kicked off a disaster that lofted vast amounts of radioactive isotopes into the air. Contamination from the plant’s radioactive cloud largely settled nearby, in a region now called the Chernobyl Exclusion Zone.

Dogs have lived in the area since the disaster, fed by Chernobyl cleanup workers and tourists. Some 250 strays were living in and around the power plant, among spent fuel-processing facilities and in the shadow of the ruined reactor. Hundreds more roam farther out in the exclusion zone, an area about the size of Yosemite National Park.
During Mousseau’s visits, his team collected blood samples from these dogs for DNA analysis, which let the researchers map out the dogs’ complex family structures. “We know who’s related to who,” says Elaine Ostrander, a geneticist at the National Human Genome Research Institute in Bethesda, Md. “We know their heritage.”

The canine packs are not just a hodgepodge of wild feral dogs, she says. “There are actually families of dogs breeding, living, existing in the power plant,” she says. “Who would have imagined?”

Dogs within the exclusion zone share ancestry with German shepherds and other shepherd breeds, like many other free-breeding dogs from Eastern Europe, the team reports. And though their work revealed that dogs in the power plant area look genetically different from dogs in Chernobyl City, about 15 kilometers away, the team does not know whether radiation caused these differences or not, Ostrander says. The dogs may be genetically distinct simply because they’re living in a relatively isolated area.

The new finding is not so surprising, says Jim Smith, an environmental scientist at the University of Portsmouth in England. He was not part of the new study but has worked in this field for decades. He’s concerned that people might assume “that the radiation has something to do with it,” he says. But “there’s no evidence of that.”

Scientists have been trying to pin down how radiation exposure at Chernobyl has affected wildlife for decades (SN: 5/2/14). “We’ve been looking at the consequences for birds and rodents and bacteria and plants,” Mousseau says. His team has found animals with elevated mutation rates, shortened life spans and early-onset cataracts.

It’s not easy to tease out the effects of low-dose radiation among other factors, Smith says. “[These studies] are so hard … there’s lots of other stuff going in the natural environment.” What’s more, animals can reap some benefits when humans leave contaminated zones, he says.

How, or if, radiation damage is piling up in dogs’ genomes is something the team is looking into now, Ostrander says. Knowing the dogs’ genetic backgrounds will make it easier to spot any radiation red flags, says Bridgett vonHoldt, an evolutionary geneticist at Princeton University, who was not involved in the work.

“I feel like it’s a cliffhanger,” she says. “I want to know more.”

SpaceX’s rapidly growing fleet of Starlink internet satellites now make up half of all active satellites in Earth orbit.

On February 27, the aerospace company launched 21 new satellites to join its broadband internet Starlink fleet. That brought the total number of active Starlink satellites to 3,660, or about 50 percent of the nearly 7,300 active satellites in orbit, according to analysis by astronomer Jonathan McDowell using data from SpaceX and the U.S. Space Force.
“These big low-orbit internet constellations have come from nowhere in 2019, to dominating the space environment in 2023,” says McDowell, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. “It really is a massive shift and a massive industrialization of low orbit.”

SpaceX has been launching Starlink satellites since 2019 with the goal of bringing broadband internet to remote parts of the globe. And for just as long, astronomers have been warning that the bright satellites could mess up their view of the cosmos by leaving streaks on telescope images as they glide past (SN: 3/12/20).

Even the Hubble Space Telescope, which orbits more than 500 kilometers above the Earth’s surface, is vulnerable to these satellite streaks, as well as those from other satellite constellations. From 2002 to 2021, the percentage of Hubble images affected by light from low-orbit satellites increased by about 50 percent, astronomer Sandor Kruk of the Max-Planck Institute for Extraterrestrial Physics in Garching, Germany, and colleagues report March 2 in Nature Astronomy.

The number of images partially blocked by satellites is still small, the team found, rising from nearly 3 percent of images taken between 2002 and 2005 to just over 4 percent between 2018 and 2021 for one of Hubble’s cameras. But there are already thousands more Starlink satellites now than there were in 2021.

“The fraction of [Hubble] images crossed by satellites is currently small with a negligible impact on science,” Kruk and colleagues write. “However, the number of satellites and space debris will only increase in the future.” The team predicts that by the 2030s, the probability of a satellite crossing Hubble’s field of view any time it takes an image will be between 20 and 50 percent.
The sudden jump in Starlink satellites also poses a problem for space traffic, says astronomer Samantha Lawler of the University of Regina in Canada. Starlink satellites all orbit at a similar distance from Earth, just above 500 kilometers.

“Starlink is the densest patch of space that has ever existed,” Lawler says. The satellites are constantly navigating out of each other’s way to avoid collisions (SN: 2/12/09). And it’s a popular orbital altitude — Hubble is there, and so is the International Space Station and the Chinese space station.
“If there is some kind of collision [between Starlinks], some kind of mishap, it could immediately affect human lives,” Lawler says.

SpaceX launches Starlink satellites roughly once per week — it launched 51 more on March 3. And they’re not the only company launching constellations of internet satellites. By the 2030s, there could be 100,000 satellites crowding low Earth orbit.

So far, there are no international regulations to curb the number of satellites a private company can launch or to limit which orbits they can occupy.

“The speed of commercial development is much faster than the speed of regulation change,” McDowell says. “There needs to be an overhaul of space traffic management and space regulation generally to cope with these massive commercial projects.”

The oldest known fossils of pollen-laden insects are of earwig-like ground-dwellers that lived in what is now Russia about 280 million years ago, researchers report. Their finding pushes back the fossil record of insects transporting pollen from one plant to another, a key aspect of modern-day pollination, by about 120 million years.

The insects — from a pollen-eating genus named Tillyardembia first described in 1937 — were typically about 1.5 centimeters long, says Alexander Khramov, a paleoentomologist at the Borissiak Paleontological Institute in Moscow. Flimsy wings probably kept the creatures mostly on the forest floor, he says, leaving them to climb trees to find and consume their pollen.

Recently, Khramov and his colleagues scrutinized 425 fossils of Tillyardembia in the institute’s collection. Six had clumps of pollen grains trapped on their heads, legs, thoraxes or abdomens, the team reports February 28 in Biology Letters. A proportion that small isn’t surprising, Khramov says, because the fossils were preserved in what started out as fine-grained sediments. The early stages of fossilization in such material would tend to wash away pollen from the insects’ remains.
The pollen-laden insects had only a couple of types of pollen trapped on them, the team found, suggesting that the critters were very selective in the tree species they visited. “That sort of specialization is in line with potential pollinators,” says Michael Engel, a paleoentomologist at the University of Kansas in Lawrence who was not involved in the study. “There’s probably vast amounts of such specialization that occurred even before Tillyardembia, we just don’t have evidence of it yet.”

Further study of these fossils might reveal if Tillyardembia had evolved special pollen-trapping hairs or other such structures on their bodies or heads, says Conrad Labandeira, a paleoecologist at the National Museum of Natural History in Washington, D.C., also not part of the study. It would also be interesting, he says, to see if something about the pollen helped it stick to the insects. If the pollen grains had structures that enabled them to clump more readily, for example, then those same features may have helped them grab Velcro-like onto any hairlike structures on the insects’ bodies.