Best Citation Awards

Giant flightless birds called mihirungs were the biggest birds to ever stride across what is now Australia. The animals, which weighed up to hundreds of kilograms, died out about 40,000 years ago. Now researchers might have a better idea why. The birds may have grown and reproduced too slowly to withstand pressures from humans’ arrival on the continent, researchers report August 17 in the Anatomical Record .  Mihirungs are sometimes called “demon ducks” because of their great size and close evolutionary relationship with present-day waterfowl and game birds. The flightless, plant-eating birds lived for more than 20 million years. Over that time, some species evolved into titans. Take Stirton’s thunderbird ( Dromornis stirtoni ). It lived about 7 million years ago, stood 3 meters tall and could exceed 500 kilograms in weight, making it the largest-known mihirung and a contender for the largest bird ever to live.  Most research on mihirungs has been on their anatomy and evo...

The first image of a black hole may conceal treasure — but physicists disagree about whether it’s been found. A team of scientists say they’ve unearthed a photon ring, a thin halo of light around the supermassive black hole in the galaxy M87. If real, the photon ring would provide a new probe of the black hole’s intense gravity. But other scientists dispute the claim. Despite multiple news headlines suggesting the photon ring has been found, many physicists remain unconvinced. Unveiled in 2019 by scientists with the Event Horizon Telescope, or EHT, the first image of a black hole revealed a doughnut-shaped glow from hot matter swirling around the black hole’s dark silhouette ( SN: 4/10/19 ). But according to Einstein’s general theory of relativity, a thinner ring should be superimposed on that thick doughnut. This ring is produced by photons, or particles of light, that orbit close to the black hole, slung around by the behemoth’s gravity before escaping and zinging toward Earth. T...

As omicron subvariant BA.5 continues to drive the coronavirus’ spread in the United States, I’ve been thinking about what could come next. Omicron and its offshoots have been topping the variant charts since last winter. Before that, delta reigned .  Scientists have a few ideas for how new variants emerge. One involves people with persistent infections — people who test positive for the virus over a prolonged period of time. I’m going to tell you about the curious case of a person infected with SARS-CoV-2 for at least 471 days and what can happen when infections roil away uncontrolled.  That lengthy infection first came onto epidemiologist Nathan Grubaugh’s radar in the summer of 2021. His team had been analyzing coronavirus strains in patient samples from Yale New Haven Hospital when Grubaugh spotted something he had seen before. Known only as B.1.517, this version of the virus never got a name like delta or omicron, nor rampaged through communities quite like its infamou...

No ifs, ands or butts about it: A teeny roughly 530-million-year-old critter that lacks an anus is not, as previously thought, the oldest member of a wide-ranging animal group that includes everything from starfish to humans. Despite its absent anus, Saccorhytus coronarius had no shortage of holes on its wrinkly potato-shaped body, including a ring of small openings around its gaping mouth. Previously, those holes had been identified as an early version of gill slits , typically used for respiration ( SN: 2/3/17 ). Gill slits are commonly found in deuterostomes, so their presence seemingly nailed the critter’s spot on the animal family tree. But a new 3-D reconstruction of the half-millimeter-long species based on fossil imaging shows those holes are instead remnants of broken spines , researchers report August 17 in Nature . The identification of the spines helped shift the creature into a group with arthropods and nematodes, called Ecdysozoa. After millions of years, fossils can ...

The massive Tonga eruption generated a set of planet-circling tsunamis that may have started out as a single mound of water roughly the height of the Statue of Liberty. What’s more, the explosive eruption triggered an immense atmospheric shock wave that spawned a second set of especially fast-moving tsunamis , a rare phenomenon that can complicate early warnings for these oft-destructive waves, researchers report in the October Ocean Engineering . As the Hunga Tonga–Hunga Ha’apai undersea volcano erupted in the South Pacific in January, it displaced a large volume of water upward, says Mohammad Heidarzadeh, a civil engineer at the University of Bath in England ( SN: 1/21/22 ). The water in that colossal mound later “ran downhill,” as fluids tend to do, to generate the initial set of tsunamis. To estimate the original size of the mound, Heidarzadeh and his team used computer simulations, as well as data from deep-ocean instruments and coastal tide gauges within about 1,500 kilometer...

It was the juice that tipped him off. At lunch, Ícaro de A.T. Pires found the flavor of his grape juice muted, flattened into just water with sugar. There was no grape goodness. “I stopped eating lunch and went to the bathroom to try to smell the toothpaste and shampoo,” says Pires, an ear, nose and throat specialist at Hospital IPO in Curitiba, Brazil. “I realized then that I couldn’t smell anything.” Pires was about three days into COVID-19 symptoms when his sense of smell vanished, an absence that left a mark on his days. On a trip to the beach two months later, he couldn’t smell the sea. “This was always a smell that brought me good memories and sensations,” Pires says. “The fact that I didn’t feel it made me realize how many things in my day weren’t as fun as before. Smell can connect to our emotions like no other sense can.” As SARS-CoV-2, the virus responsible for COVID-19, ripped across the globe, it stole the sense of smell away from millions of people, leaving them with a ...

The James Webb Space Telescope has gotten the first sniff of carbon dioxide in the atmosphere of a planet in another solar system. “It’s incontrovertible. It’s there. It’s definitely there,” says planetary scientist and study coauthor Peter Gao of the Carnegie Institution for Science in Washington, D.C. “There have been hints of carbon dioxide in previous observations, but never confirmed to such an extent.” The finding, submitted to arXiv.org on August 24, marks the first detailed scientific result published from the new telescope . It also points the way to finding the same greenhouse gas in the atmospheres of smaller, rockier planets that are more like Earth. The planet, dubbed WASP-39b, is huge and puffy. It’s a bit wider than Jupiter and about as massive as Saturn. And it orbits its star every four Earth days, making it scorching hot. Those features make it a terrible place to search for evidence of extraterrestrial life ( SN: 4/19/16 ). But that combination of puffy atmospher...

Sitting alone in the cockpit of a small biplane, Martin Wikelski listens for the pings of a machine by his side. The sonic beacons help the ecologist stalk death’s-head hawkmoths ( Acherontia atropos ) fluttering across the dark skies above Konstanz, Germany — about 80 kilometers north of the Swiss Alps. The moths, nicknamed for the skull-and-crossbones pattern on their backs, migrate thousands of kilometers between northern Africa and the Alps during the spring and fall. Many migratory insects go where the wind takes them, says Ring Carde, an entomologist at the University of California, Riverside who is not a member of Wikelski’s team. Death’s-head hawkmoths appear to be anything but typical. “When I follow them with a plane, I use very little gas,” says Wikelski, of the Max Planck Institute of Animal Behavior in Munich. “That shows me that they are supposedly choosing directions or areas that are probably supported by a little bit of updraft.” The purple line marks the path...

Higgs boson Q&A The discovery of the Higgs boson filled in a missing piece of the standard model of particle physics, which describes matter and its interactions. A decade later, physicists continue to probe the particle for clues to some of the universe’s biggest questions, Emily Conover reported in “ The Higgs boson at 10 ” ( SN: 7/2/22, p. 18 ). Conover’s tale of the Higgs boson thrilled physics enthusiasts, inspiring many comments and questions. In the piece, she explained that a Higgs boson is a wave in the Higgs field, an invisible property that pervades the cosmos. When elementary particles interact with the field, they gain mass. More massive particles interact more strongly with the field. Reader Lewis Holcombe wanted to know if elementary particles have zero mass before they interact with the field. That’s exactly the idea, Conover says. “In the early moments of the universe, before the Higgs field ‘turned on,’ all the fundamental particles were massless,” she s...

The summers of my Midwestern childhood were sticky hot. During the day, backyard sprinklers, Popsicles and squirt gun battles helped us cool off. At night, we ran window fans and hoped for cooler air. But those summer nights seem idyllic compared with the extraordinary heat waves that people around the world are suffering through now. This summer, thousands of new records have been set not just for daily high temperatures, but also for warmest overnight lows. Hot nights are dangerous because they rob people of the chance to cool down before the next sweltering day. Scientists have long known that prolonged heat waves are more deadly than a short blast. New research suggests that people may not be able to endure as much heat as once thought , earth and climate writer Carolyn Gramling reports in this issue. And those data come from young, healthy adults who were subjected to high heat for 1.5 to two hours in laboratory conditions. Older people, children and people with medical conditio...

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 ...

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 with...

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 gr...

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 uncov...

Visualizing Genes: The Possible Dream –  Science News , September 2, 1972 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...

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 experie...

On a Hawaiian mountaintop in the summer of 1992, a pair of scientists spotted a pinprick of light inching through the constellation Pisces. That unassuming object — located over a billion kilometers beyond Neptune — would rewrite our understanding of the solar system. Rather than an expanse of emptiness, there was something, a vast collection of things in fact, lurking beyond the orbits of the known planets. The scientists had discovered the Kuiper Belt, a doughnut-shaped swath of frozen objects left over from the formation of the solar system. As researchers learn more about the Kuiper Belt, the origin and evolution of our solar system is coming into clearer focus. Closeup glimpses of the Kuiper Belt’s frozen worlds have shed light on how planets, including our own, might have formed in the first place. And surveys of this region, which have collectively revealed thousands of such bodies, called Kuiper Belt objects, suggest that the early solar system was home to pinballing planets...