Humankind is seeing Neptune’s rings in a whole new light thanks to the James Webb Space Telescope.
In an infrared image released September 21, Neptune and its gossamer diadems of dust take on an ethereal glow against the inky backdrop of space. The stunning portrait is a huge improvement over the rings’ previous close-up, which was taken more than 30 years ago.
Unlike the dazzling belts encircling Saturn, Neptune’s rings appear dark and faint in visible light, making them difficult to see from Earth. The last time anyone saw Neptune’s rings was in 1989, when NASA’s Voyager 2 spacecraft, after tearing past the planet, snapped a couple grainy photos from roughly 1 million kilometers away (SN: 8/7/17). In those photos, taken in visible light, the rings appear as thin, concentric arcs.
As Voyager 2 continued to interplanetary space, Neptune’s rings once again went into hiding — until July. That’s when the James Webb Space Telescope, or JWST, turned its sharp, infrared gaze toward the planet from roughly 4.4 billion kilometers away (SN: 7/11/22). Neptune itself appears mostly dark in the new image. That’s because methane gas in the planet’s atmosphere absorbs much of its infrared light. A few bright patches mark where high-altitude methane ice clouds reflect sunlight.
And then there are the ever-elusive rings. “The rings have lots of ice and dust in them, which are extremely reflective in infrared light,” says Stefanie Milam, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., and one of JWST’s project scientists. The enormity of the telescope’s mirror also makes its images extra sharp. “JWST was designed to look at the first stars and galaxies across the universe, so we can really see fine details that we haven’t been able to see before,” Milam says.
Upcoming JWST observations will look at Neptune with other scientific instruments. That should provide new intel on the rings’ composition and dynamics, as well as on how Neptune’s clouds and storms evolve, Milam says. “There’s more to come.”
It’s not easy being ringed. A newly released image from the James Webb Space Telescope, or JWST, shows the Cartwheel Galaxy still reeling from a run-in with a smaller galaxy 400 million years ago.
The Cartwheel Galaxy, so called because of its bright inner ring and colorful outer ring, lies about 500 million light-years from Earth. Astronomers think it used to be a large spiral like the Milky Way, until a smaller galaxy smashed through it. In earlier observations with other telescopes, the space between the rings appeared shrouded in dust.
Now, JWST’s infrared cameras have peered through the dust and found previously unseen stars and structure (SN: 7/11/22). The new image shows sites of intense star formation throughout the galaxy that were triggered by the collision’s aftereffects. Some of those new stars are forming in spokelike patterns between the central ring and the outer ring, a process that is not well understood. Ring galaxies are rare, and galaxies with two rings are even more unusual. That strange shape means that the long-ago collision set up multiple waves of gas rippling back and forth in the galaxy left behind. It’s like if you drop a pebble in the bathtub, says JWST project scientist Klaus Pontoppidan of the Space Telescope Science Institute in Baltimore. “First you get this ring, then it hits the walls of your bathtub and reflects back, and you get a more complicated structure.”
The effect probably means that the Cartwheel Galaxy has a long road to recovery ahead — and astronomers don’t know what it will look like in the end.
As for the smaller galaxy that caused all this mayhem, it didn’t stick around to get its picture taken. “It’s gone off on its merry way,” Pontoppidan says.
Lionfish certainly aren’t the fastest predators on the reef, but new research suggests that they can catch swift prey through pure tenacity, gliding slowly in pursuit until the perfect moment to strike.
The finding may help explain part of the lionfish’s impact as an invasive species, and reveal a key hunting strategy that other relatively slow predators use, researchers report August 2 in Proceedings of the Royal Society B.
Festooned with long striped spines, lionfish can make their surreal silhouettes disappear against a coral reef backdrop long enough to stalk and ambush small fish. But the predators also feed in open water where they’re more visible. Curious about how the predators hunt in plain view, Ashley Peterson, a comparative biomechanist at the University of California, Irvine, and her colleagues placed red lionfish (Pterois volitans) in a tank and recorded them as they chased down a green chromis (Chromis viridis), a small reef fish.
In 14 of the 23 trials, the lionfish successfully gulped down their prey. They also had a high rate of strike success, capturing the chromis in 74 percent of the trials where the lionfish made a strike attempt.
On average, the chromis swam about twice as fast as the lionfish. But many still fell victim to what Peterson and biomechanist Matthew McHenry, also at the University of California, Irvine, call a persistent-predation strategy — the lionfish swim toward a chromis, aiming for its current position, not the direction to intercept its path. And the lionfish’s pursuit is steady and incessant, the team found.
“If they’re interested in something and they want to try to eat it, they just seem to not give up,” Peterson says.
In contrast, the prey fish does bursts of fast swimming along with short pauses.
“Over time, all those pauses add up and allow this lionfish to get closer and closer and closer,” Peterson says. Then the slightest mistake or bit of distraction can doom the prey to the lionfish’s suction-creating jaws.
“This is a good example of ‘slow and steady wins the race,’” says Bridie Allan, a marine ecologist at the University of Otago in Dunedin, New Zealand who was not involved in the research. It would be interesting to see how the unwavering chase plays out in the wild, where there are no spatial restrictions like in a tank, she says.
If lionfish do use the strategy in the wild and prey react similarly, it’s possible that the tactic could contribute to the destructive potential of their invasion in the Caribbean, Western Atlantic and the Mediterranean, where the fish are devouring native ocean animals and disrupting food webs (SN: 7/6/16). But other factors, such as the lionfish’s huge appetite or prolific reproduction, could be more influential on invasiveness.
The persistent-predation strategy may not be exclusive to lionfish, Peterson says. Other predatory fish groups with sluggish swimmers — like straw-shaped trumpetfish (Aulostomus spp.) — could also use it.
In a natural setting, prey that are dodging lionfish and other slow swimmers may have more places to hide, Peterson says. But there are inherent risks in a busy, distracting environment too. “If you’re near a reef or up against the coral, you could get pinned if you aren’t really paying attention,” she says. That’s when determined and hungry slowpokes may have the upper hand.
Call it cellular life support for dead pigs. A complex web of pumps, sensors and artificial fluid can move oxygen, nutrients and drugs into pigs’ bodies, preserving cells in organs that would otherwise deteriorate after the heart stops pumping.
The finding, described August 3 in Nature, is preliminary, but it hints at new ways to keep organs in a body healthy until they can be used for transplantation.
In earlier work, scientists built a machine they named BrainEx, which kept aspects of cellular life chugging along in decapitated, oxygen-deprived pig brains (SN: 4/17/19). The new system, called OrganEx, pushes the approach to organs beyond the brain. “We wanted to see if we could replicate our findings in other damaged organs across the body, and potentially open the door for future transplantation studies,” says Nenad Sestan, a neuroscientist at Yale University School of Medicine.
OrganEx aims to do the job of hearts and lungs by pumping an artificial fluid throughout pig bodies. Mixed in a 1–1 ratio with the animals’ own blood, the lab-made fluid has ingredients that provide fresh oxygen and nutrients, prevent clots and protect against inflammation and cell death.
Anesthetized pigs were put into cardiac arrest and then left alone for an hour. Then some pigs were placed on an existing medical system, called extracorporeal membrane oxygenation, or ECMO. This adds oxygen to the pigs’ own blood and pumps it into their body. Other pigs received the OrganEx treatment.
Compared with ECMO, OrganEx provided more fluid to tissues and organs, the researchers found. Fewer cells died, and some tissues, including kidneys, even showed cellular signs of repairing themselves from the damage done after the heart stopped.
A similar system might one day be useful for protecting human organs destined to be donated. But for now, “there is still lots of work to be done in our animal model,” Sestan says.
Sometimes a photo is literally a matter of life, death — and zombies.
This haunting image, winner of the 2022 BMC Ecology and Evolution photography competition, certainly fits that description. It captures the fruiting bodies of a parasitic fungus, emerging from the lifeless body of an infected fly in the Peruvian rainforest.
The fungus-infested fly was one of many images submitted to the contest from all over the world, aiming to showcase the beauty of the natural world and the challenges it faces. The journal revealed the winners August 18. Roberto García-Roa, a conservation photographer and evolutionary biologist at the University of Valencia in Spain, took the winning photo while visiting the Tambopata National Reserve, a protected habitat in the Amazon.
The fungus erupting from the fly belongs to the genus Ophiocordyceps, a diverse collection of parasitic fungi known as “zombie fungi,” due to their ability to infect insects and control their minds (SN: 7/17/19).
“There is still much to unravel about the diversity of these fungi as it is likely that each insect species infected succumbs to its own, specialized fungus,” says Charissa de Bekker, an expert in parasitic fungi at Utrecht University in the Netherlands.
First, spores of the fungus land on the ill-fated fly. So begins the manipulative endgame. The spores infiltrate the fly’s exoskeleton before infecting its body and eventually hijacking its mind. Once in control, the fungus uses its new powers of locomotion to relocate to a microclimate more suitable to its own growth — somewhere with the right temperature, light and moisture.
Fungus and fly then bide their time until the fly dies, becoming a food source for the fungus to consume. Fruiting bodies work their way out of the fly, filled with spores that are released into the air to continue the macabre cycle in a new, unsuspecting host. It is a “conquest shaped by thousands of years of evolution,” García-Roa said in a statement announcing the winners.
Research into the molecular aspects of fungal mind control is under way, De Bekker says, including in her own lab. “These fungi harbor all sorts of bioactive chemicals that we have yet to characterize and that could have novel medicinal and pest control applications.”
Archaeologist Peter Bellwood’s academic odyssey wended from England to teaching posts halfway around the world, first in New Zealand and then in Australia. For more than 50 years, he has studied how humans settled islands from Southeast Asia to Polynesia.
So it’s fitting that his new book, a plain-English summary of what’s known and what’s not about the evolution of humans and our ancestors, emphasizes movement. In The Five-Million-Year Odyssey, Bellwood examines a parade of species in the human evolutionary family — he collectively refers to them as hominins, whereas some others (including Science News) use the term hominids (SN: 9/15/21) — and tracks their migrations across land and sea. He marshals evidence indicating that hominids in motion continually shifted the direction of biological and cultural evolution. Throughout his tour, Bellwood presents his own take on contested topics. But when available evidence leaves a debate unresolved, he says so. Consider the earliest hominids. Species from at least 4.4 million years ago or more whose hominid status is controversial, such as Ardipithecus ramidus, get a brief mention. Bellwood renders no verdict on whether those finds come from early hominids or ancient apes. He focuses instead on African australopithecines, a set of upright but partly apelike species thought to have included populations that evolved into members of our own genus, Homo, around 2.5 million to 3 million years ago. Bellwood hammers home the point that stone-tool making by the last australopithecines, the first Homo groups or both contributed to the evolution of bigger brains in our ancestors.
The action speeds up when Homo erectus becomes the first known hominid to leave Africa, roughly 2 million years ago. Questions remain, Bellwood writes, about how many such migrations occurred and whether this humanlike species reached distant islands such as Flores in Indonesia, perhaps giving rise to small hominids called hobbits, or Homo floresiensis (SN: 3/30/16). What’s clear is that H. erectus groups journeyed across mainland Asia and at least as far as the Indonesian island of Java.
Intercontinental migrations flourished after Homo sapiens debuted, around 300,000 years ago in Africa. Bellwood regards H. sapiens, Neandertals and Denisovans as distinct species that interbred in certain parts of Asia and Europe. He suggests that Neandertals disappeared around 40,000 years ago as they mated with members of more numerous H. sapiens populations, leaving a genetic legacy in people today. But he does not address an opposing argument that different Homo populations at this time, including Neandertals, were too closely related to have been separate species and that it was intermittent mating among these mobile groups that drove the evolution of present-day humans (SN: 6/5/21).
Bellwood gives considerable attention to the rise of food production and domestication in Europe and Asia after around 9,000 years ago. He builds on an argument, derived from his 2004 book First Farmers, that expanding populations of early cultivators migrated to new lands in such great numbers that they spread major language families with them. For instance, farmers in what’s now Turkey spread Indo-European languages into much of Europe sometime after roughly 8,000 years ago, Bellwood contends.
He rejects a recent alternative proposal, based on ancient DNA evidence, that horse-riding herders of Central Asia’s Yamnaya culture brought their traditions and Indo-European tongues to Europe around 5,000 years ago (SN: 11/15/17). Too few Yamnaya immigrated to impose a new language on European communities, Bellwood says. Similarly, he argues, ancient Eurasian conquerors, from Alexander the Great to Roman emperors, couldn’t get speakers of regional languages to adopt new ones spoken by their outnumbered military masters.
Bellwood rounds out his evolutionary odyssey with a reconstruction of how early agricultural populations expanded through East Asia and beyond, to Australia, a string of Pacific islands and the Americas. Between about 4,000 and 750 years ago, for instance, sea-faring farmers spread Austronesian languages from southern China and Taiwan to Madagascar in the west and Polynesia in the east. Precisely how they accomplished that remarkable feat remains a puzzle.
Disappointingly, Bellwood doesn’t weigh in on a recent archaeological argument that ancient societies were more flexible and complex than long assumed (SN: 11/9/21). On the plus side, his evolutionary odyssey moves along at a brisk pace and, like our ancestors, covers a lot of ground.
Across the United States, kids are prepping for back-to-school, or are already in classrooms, and parents are buckling up for another pandemic school year. Like me, many are trying to get a handle on what COVID-19 precautions to take. Updated guidance released last week by the U.S. Centers for Disease Control and Prevention hasn’t exactly helped. It may have made dealing with back-to-school more confusing — and could even spur new outbreaks.
Last November, my fifth grader had to quarantine at home for 10 days after a close contact tested positive. Now, the CDC has nixed the quarantine recommendation for people exposed to COVID-19. Today, our situation could look something like this: My COVID-exposed daughter would mask for 10 days, test on day five, and remain in school the whole time — only the infected child would isolate. That child would stay home for at least five days after a positive test. Then, if the child is fever-free and symptoms are improving, according to the new guidance, they could pop on a mask and hightail it back to class — no testing needed. That advice could mean more COVID-19 in classrooms. Scientists have shown that people can remain infectious after day five. So without testing for COVID-19, students and teachers won’t know if they’re bringing the disease back to school.
On the same day the CDC’s guidance came out, the U.S. Food and Drug Administration added yet another wrinkle. If you think you’ve been exposed to COVID-19 but test negative with an at-home COVID-19 antigen test, the FDA now recommends testing again … and again. Repeat testing over time cuts the chances you’ll miss an infection and unknowingly spread the virus, the FDA advised on August 11.
It’s hard to say how that advice jibes with the CDC’s new, more-relaxed guidelines. Even the agency has said its public guidance during the pandemic has been “confusing and overwhelming,” the New York Times reports. CDC director Rochelle Walensky is now planning a shake-up that could include restructuring the communications office as well as relying more on preliminary studies rather than waiting for research to go through peer-review, according to NPR. The CDC’s new guidance has sparked a range of reactions, many negative, among scientists, doctors, parents and teachers. In an informal Twitter poll of Science News followers, roughly 80 percent of the 353 respondents reported that the new CDC guidance made them feel confused, worried or angry and/or exasperated.
Now, it’s up to local school districts to decide what COVID-19 measures to take. “Just because guidance has changed does not mean COVID is gone,” Becky Pringle, president of the National Education Association labor union, said in a statement. Not by a long shot. The United States is currently averaging nearly 500 daily coronavirus deaths and more than 100,000 new cases a day, an almost certain undercount.
As my own children gear up for school, I wonder about COVID-19’s constantly shifting landscape. Like other families with school-aged children, we’ve bounced from virtual school to in-person mask mandates to mask-optional recommendations. And we still don’t know our district’s plans for the upcoming year. School starts in about a week.
There is reason for hope, though: We know what measures can slow COVID-19’s spread in schools. Masking is a big one. A preliminary study posted August 9 linked lifting school mask mandates in Boston-area K–12 schools with a rise in cases among students and staff. At Boston University, mandatory masking plus a vaccine mandate seemed to keep the virus in check in classrooms, scientists reported August 5 in JAMA Network Open. Testing can help, too. A computer analysis from England suggests that regularly rapid testing students can curb classroom transmission, scientists report August 10 in the Royal Society Open Science. But knowing what works is not the same as actually employing evidence-based measures in the classroom, says Anne Sosin, a public health researcher at Dartmouth College whose research focuses on COVID-19 and rural health equity. She has studied how pandemic policies have impacted schools in northern New England. “I worry that we simply have not seen the political leadership to ensure that all children and educators can safely participate in school.”
I spoke with Sosin about the CDC’s new guidance, and what kids and parents might expect heading into the new school year. Our conversation has been edited for length and clarity.
SN: What do you think of the updated guidance?
Sosin: I was very disappointed that the CDC did not adopt a test-to-exit-isolation recommendation.
What we’re going to see in schools are infected students and educators returning after five days still positive for COVID-19. Multiple studies have demonstrated that most people are infectious beyond five days. Not only is it highly likely that they’ll be seeding outbreaks. They’ll also be putting high-risk members of school communities in danger.
SN: What could the guidance mean for vulnerable kids?
Sosin: I think that vulnerable people are going to be in a very precarious situation. The guidance mentions the need to ensure protections for immunocompromised and other high-risk people but there’s a problem of implementation. Will schools actually implement those protections?
SN: Do scientists have a good handle on what protections can help?
Sosin: Definitely. We have really strong evidence showing that when layered mitigation strategies are in place, we can almost eliminate transmission in school settings. That means that we should have upgraded ventilation, lunchroom strategies [like taking kids outside to eat] and testing. And I continue to think that data-driven mask policies have a role to play. Not masking forever, but masking at times when we see an uptick in transmission.
SN: How could the new guidance affect different communities across the United States?
Sosin: Different communities have not only been impacted in dramatically different ways, but they’re also on unequal footing at this stage of the pandemic.
[If we compare white communities with communities of color], we see disparities in vaccination coverage and caregiver loss. Some communities have suffered enormous losses while others have really been untouched. Black children have lost caregivers at more than two times the rate of white children. For Indigenous children, the rate is 4.5 times as high. Those are sharp disparities.
Communities of color also have less access to testing, treatment and health care. I worry that if we don’t have a renewed focus on equity, then we’re just going to see an exacerbation of disparities that have existed throughout the pandemic.
SN: What advice do you have for parents as they head into the new school year?
Sosin: We all want as normal a school year as possible. Masking should be one of the tools we’re ready to employ to keep our kids in the classroom. In addition, we should be advocating that our schools invest in ventilation. Vaccination also represents a critical piece of the strategy.
We see such abysmal vaccination coverage among children. Less than 1 in 3 kids ages 5 to 11 are fully vaccinated. I think many parents no longer see it as important — there’s been this narrative that the pandemic is over. We need clear messaging that vaccination remains an important tool.
Now is a great time to plan back-to-school campaigns to vaccinate kids and to begin to prepare for the arrival of omicron-specific boosters in the fall.
There’s nothing like a big mass extinction to open up ecological niches and clear out the competition, accelerating evolution for some lucky survivors. Or is there? A new study suggests that the rate of climate change may play just as large a role in speeding up evolution.
The study focuses on reptile evolution across 57 million years — before, during and after the mass extinction at the end of the Permian Period (SN: 12/6/18). That extinction event, triggered by carbon dioxide pumped into the atmosphere and oceans through increased volcanic activity about 252 million years ago, knocked out a whopping 86 percent of Earth’s species. Yet reptiles recovered from the chaos relatively well. Their exploding diversity of species around that time has been widely regarded as a result of their slithering into newly available niches. But rapid climate fluctuations were already taking place much earlier in the Permian, and so were surges of reptile diversification, researchers say. Analyzing fossils from 125 reptile species shows that bursts of evolutionary diversity in reptiles were tightly correlated with relatively rapid fluctuations in climate throughout the Permian and millions of years into the next geologic period, the Triassic, researchers report August 19 in Science Advances.
Scientists’ understanding of evolution is expanding as they become more tuned into the connection between it and environmental change, says Jessica Whiteside, a geologist at the University of Southampton in England who works on mass extinctions but was not involved in the new work. “This study is bound to become an important part of that conversation.”
To investigate reptile evolution, evolutionary paleobiologist Tiago Simões of Harvard University and colleagues precisely measured and scanned reptile fossils ranging from 294 million to 237 million years old. In all, the researchers examined 1,000 specimens at 50 research institutions in 20 countries. For climate data, the team used an existing large database of sea surface temperatures based on oxygen isotope data, extending back 450 million years, published in 2021.
By closely tracking changes in body and head size and shape in so many species, paired with that climate data, the researchers found that the faster the rate of climate change, the faster reptiles evolved. The fastest rate of reptile diversification did not occur at the end-Permian extinction, the team found, but several million years later in the Triassic, when climate change was at its most rapid and global temperatures witheringly hot. Ocean surface temperatures during this time soared to 40° Celsius, or 104⁰ Fahrenheit — about the temperature of a hot tub, says Simões.
A few species did evolve less rapidly than their kin, Simões says. The difference? Size. For instance, reptiles with smaller body sizes are already preadapted to live in rapidly warming climates, he says. Due to their greater surface area to body ratio, “small-bodied reptiles can better exchange heat with their surrounding environment,” so stay relatively cooler than larger animals.
“The smaller reptiles were basically being forced by natural selection to stay the same, while during that same period of time, the large reptiles were being told by natural selection ‘You need to change right away or you’re going to go extinct,’” Simões says.
This phenomenon, called the Lilliput effect, is not a new proposal, Simões says, adding that it’s been well established in marine organisms. “But it’s the first time it’s been quantified in limbed vertebrates across this critical period in Earth’s history.”
Simões and colleagues’ detailed work has refined the complex evolutionary tree for reptiles and their ancestors. But, for now, it’s unclear which played a bigger role in reptile evolution long ago — all those open ecological niches after the end-Permian mass extinction, or the dramatic climate fluctuations outside of the extinction event.
“We cannot say which one was more important,” Simões says. “Without either one, the course of evolution in the Triassic and the rise of reptiles to global dominance in terrestrial ecosystems would have been quite different.”
When Herminia Pasantes Ordóñez was about 14 years old, in 1950, she heard her mother tell her father that she would never find a husband. Pasantes had to wear thick glasses for her poor eyesight. In her mother’s eyes, those glasses meant her future as a “good woman” was doomed. “This made my life easier,” says Pasantes, “because it was already said that I was going to study.”
At a time when it was uncommon for women to become scientists, Pasantes studied biology at the National Autonomous University of Mexico in Mexico City, or UNAM. She was the first member of her family to go to college. She became a neurobiologist and one of the most important Mexican scientists of her time. Her studies on the role of the chemical taurine in the brain offer deep insights into how cells maintain their size — essential to proper functioning. In 2001, she became the first woman to earn Mexico’s National Prize for Sciences and Arts in the area of physical, mathematical and natural sciences.
“We basically learned about cell volume regulation through the eyes and work of Herminia,” says Alexander Mongin, a Belarusian neuroscientist at Albany Medical College in New York.
Pasantes did get married, in 1965 while doing her master’s in biochemistry at UNAM. She had a daughter in 1966 and a son in 1967 before starting a Ph.D. in natural sciences in 1970 at the Center for Neurochemistry at the University of Strasbourg in France. There, she worked in the laboratory of Paul Mandel, a Polish pioneer in neurochemistry.
The lab was trying to find out everything there was to know about the retina, the layer of tissue at the back of the eye that is sensitive to light. Pasantes decided to test whether free amino acids, a group that aren’t incorporated into proteins, were present in the retinas and brain of mice. Her first chromatography — a lab technique that lets scientists separate and identify the components of a sample — showed an immense amount of taurine in both tissues. Taurine would drive the rest of her scientific career, including work in her own lab, which she started around 1975 at the Institute of Cellular Physiology at UNAM.
Taurine turns out to be widely distributed in animal tissues and has diverse biological functions, some of which were discovered by Pasantes. Her research found that taurine helps maintain cell volume in nerve cells, and that it protects brain, muscle, heart and retinal cells by preventing the death of stem cells, which give rise to all specialized cells in the body. Contrary to what most scientists had believed at the time, taurine didn’t work as a neurotransmitter sending messages between nerve cells. Pasantes demonstrated for the first time that it worked as an osmolyte in the brain. Osmolytes help maintain the size and integrity of cells by opening up channels in their membranes to get water in or out.
Pasantes says she spent many years looking for an answer for why there is so much taurine in the brain. “When you ask nature a question, 80 to 90 percent of the time, it responds no,” she says. “But when it answers yes, it’s wonderful.”
Pasantes’ lab was one of the big four labs that did groundbreaking work on cell volume regulation in the brain, says Mongin.
Her work and that of others proved taurine has a protective effect; it’s the reason the chemical is today sprinkled in the containers that carry organs for transplants. Pasantes’ work was the foundation for our understanding of how to prevent and treat brain edema, a condition where the brain swells due to excessive accumulation of fluid, from head trauma or reduced blood supply, for example. She and other experts also reviewed the role of taurine for Red Bull, which added the chemical to its formula because of potentially protective effects in the heart.
Pasantes stopped doing research in 2019 and spends her time talking and writing about science. She hopes her story speaks to women around the world who wish to be scientists: “It is important to send the message that it is possible,” she says.
Years before she was accepted into Mandel’s lab, her application to a Ph.D. in biochemistry at the UNAM was rejected. Pasantes says the reason was that she had just had her daughter. Looking back, this moment was “one of the most wonderful things that could’ve happened to me,” Pasantes says, because she ended up in Strasbourg, where her potential as a researcher bloomed.
Rosa María González Victoria, a social scientist at the Autonomous University of the State of Hidalgo in Pachuca, Mexico, who specializes in gender studies, recently interviewed Pasantes for a book about Mexican women in science. González Victoria thinks Pasantes’ response to that early rejection speaks to the kind of person she is: “A woman that takes those no’s and turns them into yes’s.”
A fast-spinning neutron star south of the constellation Leo is the most massive of its kind seen so far, according to new observations.
The record-setting collapsed star, named PSR J0952-0607, weighs about 2.35 times as much as the sun, researchers report July 11 on arXiv.org. “That’s the heaviest well-measured neutron star that has been found to date,” says study coauthor Roger Romani, an astrophysicist at Stanford University.
The previous record holder was a neutron star in the northern constellation Camelopardalis named PSR J0740+6620, which tipped the scales at about 2.08 times as massive as the sun. If a neutron star grows too massive, it collapses under its own weight and becomes a black hole. These measurements of hefty neutron stars are of interest because no one knows the exact mass boundary between neutron stars and black holes. That dividing line drives the quest to find the most massive neutron stars and determine just how massive they can be, Romani says. “It’s defining the boundary between the visible things in the universe and the stuff that is forever hidden from us inside of a black hole,” he says. “A neutron star that’s on the hairy edge of becoming a black hole — just about heavy enough to collapse — has at its center the very densest material that we can access in the entire visible universe.”
PSR J0952-0607 is in the constellation Sextans, just south of Leo. It resides 20,000 light-years from Earth, far above the galaxy’s plane in the Milky Way’s halo. The neutron star emits a pulse of radio waves toward us each time it spins, so astronomers also classify the object as a pulsar. First reported in 2017, this pulsar spins every 1.41 milliseconds, faster than all but one other pulsar.
That’s why Romani and his colleagues chose to study it — the fast spin led them to suspect that the pulsar might be unusually heavy. That’s because another star orbits the pulsar, and just as water spilling over a water wheel spins it up, gas falling from that companion onto the pulsar could have sped up its rotation while also boosting its mass.
Observing the companion, Romani and his colleagues found that it whips around the pulsar quickly — at about 380 kilometers per second. Using the companion’s speed and its orbital period of about six and a half hours, the team calculated the pulsar’s mass to be more than twice the mass of the sun. That’s a lot heavier than the typical neutron star, which is only about 1.4 times as massive as the sun.
“It’s a terrific study,” says Emmanuel Fonseca, a radio astronomer at West Virginia University in Morgantown who measured the mass of the previous record holder but was not involved in the new work. “It helps nuclear physicists actually constrain the nature of matter within these extreme environments.”
