Category: 7. Science

Scientists studying samples from the asteroid Bennu have found that it contains a remarkable mix of materials — some of which formed long before the sun even existed.

Taken together, the findings, described in a trio of recently published papers, show how Bennu has preserved clues about the earliest days of our solar system.

Arthropod appendages are specialized for diverse roles including feeding, walking, and mating. Fossils from the Cambrian period (539 to 487 million years ago) preserve exceptional details of extinct arthropod appendages that can illuminate their anatomy and ecology. However, fossils are typically limited by small sample sizes or incomplete preservation, and thus functional studies of the appendages usually rely on idealized reconstructions. In new research, paleontologists focused on Olenoides serratus, a particularly abundant trilobite species in the Cambrian Burgess Shale that is unique among trilobites owing to the availability of numerous specimens with soft tissue preservation that allow us to quantify its appendages’ functional morphology.

The Burgess Shale in British Columbia, Canada, is renowned for its exceptional preservation of soft tissues in fossils, including limbs and guts.

While trilobites are abundant in the fossil record thanks to their hard exoskeleton, their soft limbs are rarely preserved and poorly understood.

The trilobite species Olenoides serratus offers a unique opportunity to study these appendages.

Harvard University paleontologist Sarah Losso and her colleagues analyzed 156 limbs from 28 fossil specimens of Olenoides serratus to reconstruct the precise movement and function of these ancient arthropod appendages, shedding light on one of the planet’s earliest and most successful animals.

“Understanding behavior and movement of fossils is challenging, because you cannot observe this activity like in living animals,” Dr. Losso said.

“Instead, we had to rely on carefully examining the morphology in as many specimens as possible, as well as using modern analogues to understand how these ancient animals lived.”

The researchers also measured the range of motion of the legs in the living horseshoe crab species Limulus polyphemus.

“Arthropods have jointed legs composed of multiple segments that can reach upwards (extend) or downwards (flex),” they said.

“The range of motion depends on the difference between how far each joint can reach in either direction.”

“This range, along with the leg and shape of each segment, determines how the animal uses the limb for walking, grabbing, and burrowing.”

“Horseshoe crabs, common arthropods found along the eastern shore of North America, are frequently compared to trilobites even though they are not closely related.”

“Horseshoe crabs belong to a different branch of the arthropod tree, more closely related to spiders and scorpions, whereas trilobites’ family ties remain uncertain.”

“The comparison is due to the similarity in that both animals patrol the ocean floor on jointed legs.”

“The results, however, showed less similarity between the two animals.”

Unlike horseshoe crabs, whose limb joints alternate in their specialization for flexing and extending — a pattern that facilitates both feeding and protection — Olenoides serratus displayed a simpler, but highly functional limb design.

“We found that the limbs of Olenoides serratus had a smaller range of extension and only in the part of the limb farther from the body,” Dr. Losso said.

“Although their limbs were not used in exactly the same way as horseshoe crabs, Olenoides serratus could walk, burrow, bring food towards its mouth, and even raise its body above the seafloor.”

To bring their findings to life, the scientists created sophisticated 3D digital models based on hundreds of fossil images preserved at different angles.

Because fossilized trilobite limbs are usually squashed flat, reconstructing them in three-dimensions posed a challenge.

“We relied on exceptionally well-preserved specimens, comparing limb preservation across many angles and filling in missing details using related fossils,” said Harvard University’s Professor Javier Ortega-Hernández.

The team compared the shape of trace fossils with the movement of the limbs.

“Olenoides serratus could create trace fossils of different depths using different movements,” Dr. Losso explained.

“They could raise their body above the sediment in order to walk over obstacles or to move more efficiently in fast-flowing water.”

“Surprisingly, we discovered that the male species also had specialized appendages used for mating, and that each leg also had a gill used for breathing.”

The results were published on August 4, 2025 in the journal BMC Biology.

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S.R. Losso et al. 2025. Quantification of leg mobility in the Burgess Shale Olenoides serratus indicates functional differences between trilobite and xiphosuran appendages. BMC Biol 23, 238; doi: 10.1186/s12915-025-02335-3

As the Northern Hemisphere prepares for the autumnal equinox on September 22 and pumpkin-flavoured treats return in full force, the night sky is also offering a seasonal spectacle for skywatchers.

NASA says early risers on September 19 will be treated to a striking celestial trio just before sunrise. In the eastern sky, the Moon will appear closely aligned with Venus and Regulus, one of the brightest stars in the night sky. This rare conjunction offers a beautiful visual for both seasoned astronomers and casual skywatchers alike.

Later in the month, on September 21, Saturn will take center stage as Earth moves directly between Saturn and the Sun, During this time, Saturn will be at its closest and brightest point of the year. According to NASA, the planet’s iconic rings will be visible with just a small telescope, making this an ideal opportunity for backyard astronomers to get a clear view.

“Aside from the autumnal equinox in the Northern Hemisphere on Sept. 22 and the increase of pumpkin-flavored treats, September offers some celestial sights to enjoy. Just before sunrise on Sept. 19, you can catch a glimpse of a celestial trio. In the eastern skies, you will find the Moon cozied up to Venus and Regulus, one of the brightest stars in the sky,” NASA said.

It added, “A few days later on Sept. 21, Earth will position itself directly between Saturn and the Sun, meaning that Saturn will be at its closest and brightest all year. If you want to see its rings, all you will need is a small telescope.”

Here’s how you can watch Conjunction trio and Saturn at Opposition

According to NASA, the planet’s iconic rings will be visible with just a small telescope, making this an ideal opportunity for backyard astronomers to get a clear view.

“If you look to the east just before sunrise on September 19, you’ll see a trio of celestial objects in a magnificent conjunction. In the early pre-dawn hours, look east toward the waning, crescent Moon setting in the sky and you’ll notice something peculiar. The Moon will be nestled up right next to both Venus and Regulus, one of the brightest stars in the night sky,” NASA said.

It further mentioned, “The three are part of a conjunction, which simply means that they look close together in the sky (even if they’re actually far apart in space). To find this conjunction, just look to the Moon. And if you want some additional astronomical context, or want to specifically locate Regulus, this star lies within the constellation Leo, the lion.”

“Saturn will be putting on an out-of-this-world performance this month. Saturn will be visible with just your eyes in the night sky, but with a small telescope, you might be able to see its rings!” it added.

Researchers at University College London have discovered that activated amino acids and sulfur-containing compounds called thiols—both likely present on early Earth—can react in water at neutral pH to form high-energy thioesters. These thioesters transfer the activated amino acids to RNA in a process called RNA aminoacylation, preventing them from joining with free-floating amino acids. These findings suggest that thioesters may have provided the energy needed to unite nucleic acids and amino acids for protein biosynthesis—without the need for enzymes—in Earth’s earliest life-forms.

Proteins are essential to all life on Earth but, unlike nucleic acids such as DNA and RNA, cannot themselves pass specific sequences to their “offspring.”

“This is why life coordinates protein synthesis with another molecule, specifically RNA,” says Matthew W. Powner, lead author of the study (Nature 2025, DOI: 10.1038/s41586-025-09388-y).

In modern cells, enzymes called aminoacyl–transfer RNA (tRNA) synthetases attach amino acids to tRNA, activating them and programming the translation of RNA into proteins. But these enzymes themselves are products of the same genetic code—so how were they made in the first place? “Because you need these proteins to synthesize proteins, it’s a classic chicken-and-the-egg paradox,” Powner says. At life’s origin, these enzymes didn’t exist yet, so the team tried to figure out how amino acids attached to RNA spontaneously in water—the first way life would have had to connect genetic information to functional proteins.

Developing activated amino acids that react selectively with the 2′,3′-hydroxyl (–OH) groups of the ribose sugar of RNA—without enzymes and with other types of molecules that would be present in a cell or the early Earth at the origins of life—has proven challenging. Past attempts have led to hydrolysis or amino acids reacting with themselves. So the team considered the role that thioesters might play in this process.

Thioesters are high-energy compounds that are important in many of life’s biochemical processes and, like RNA aminoacylation, have ancient roots in biochemistry that predate the last universal common ancestor of all life on Earth. In the 1990s, Nobel laureate and biochemist Christian de Duve came up with the “thioester world” hypothesis, which posits that, based on their central role in metabolism, life’s first reactions must have been “powered” by thioesters.

After synthesizing and purifying nucleotides, nucleic acids, and activated amino acids, the team added thioesters to water at neutral pH at varying temperatures from ambient to freezing. They found that the thioesters were surprisingly stable in water, avoiding unwanted peptide formation between amino acids. In the presence of double-stranded RNA structures, thioesters selectively attached amino acids to the 2′,3′-diol groups of the ribose sugar at the 3′ of the double strand, even amid bulk water and excess amines.

The team then tested whether RNA could attach a variety of amino acids in water and found that aminoacylation occurred across all four RNA nucleotides on a broad range of amino acids, including charge residues such as arginine and lysine.

Finally the researchers investigated how these amino acids that were attached to RNA could be used for peptide synthesis under the same plausible prebiotic conditions. They found that when thioesters react with hydrogen sulfide, they form highly reactive thioacids. Those compounds could then be activated to bond with amino acids, even those attached to RNA—switching on peptide synthesis. Ultimately they found that thioesters were selective for aminoacylating RNA, while thioacids enable peptide bond formation, which allows for the stepwise, controlled synthesis of peptides attached to RNA.“A key step missing from prebiotic studies until now has been the use of chemical free energy transfer reactions to overcome the uphill chemistry of assembling polymers in water,” says Charlie Carter, a biochemist and biophysicist at the University of North Carolina School of Medicine who was not involved in this study. “The simplicity of the chemistry used here strongly suggests that it played a significant role in helping to create conditions for life to emerge,” he adds.

Astronomers have discovered an extraordinary celestial system containing a runaway pulsar fleeing the scene of a massive stellar supernova explosion. What makes this system even more spectacular is the fact that it should be “forbidden” in the empty region of the Milky Way in which it was found.

The system, given the name “Calvera” after the villain in the 1960 Western “The Magnificent Seven,” exists around 6,500 light-years above the densely populated plane of the Milky Way. In this region, stellar populations are sparse, and stars with the necessary mass needed to go supernova and to birth a neutron star at the heart of a pulsar should be vanishingly rare.

Robots can serve pizza, crawl over alien planets, swim like octopuses and jellyfish, cosplay as humans, and even perform surgery. But can they walk on water?

Rhagobot isn’t exactly the first thing that comes to mind at the mention of a robot. Inspired by Rhagovelia water striders, semiaquatic insects also known as ripple bugs, these tiny bots can glide across rushing streams because of the robotization of an evolutionary adaptation.

Rhagovelia (as opposed to other species of water striders) have fan-like appendages toward the ends of their middle legs that passively open and close depending on how the water beneath them is moving. This is why they appear to glide effortlessly across the water’s surface. Biologist Victor Ortega-Jimenez of the University of California, Berkeley, was intrigued by how such tiny insects can accelerate and pull off rapid turns and other maneuvers, almost as if they are flying across a liquid surface.

“Rhagovelia’s fan serves as an inspiring template for developing self-morphing artificial propellers, providing insights into their biological form and function,” he said in a study recently published in Science. “Such configurations are largely unexplored in semi-aquatic robots.”

Mighty morphin’

It took Ortega-Jimenez five years to figure out how the bugs get around. While Rhagovelia leg fans were thought to morph because they were powered by muscle, he found that the appendages automatically adjusted to the surface tension and elastic forces beneath them, passively opening and closing ten times faster than it takes to blink. They expand immediately when making contact with water and change shape depending on the flow.

By covering an extensive surface area for their size and maintaining their shape when the insects move their legs, Rhagovelia fans generate a tremendous amount of propulsion. They also do double duty. Despite being rigid enough to resist deformation when extended, the fans are still flexible enough to easily collapse, adhering to the claw above to keep from getting in the animal’s way when it’s out of water. It also helps that the insects have hydrophobic legs that repel water that could otherwise weigh them down.

Ortega-Jimenez and his research team observed the leg fans using a scanning electron microscope. If they were going to create a robot based on ripple bugs, they needed to know the exact structure they were going for. After experimenting with cylindrical fans, the researchers found that Rhagovellia fans are actually structures made of many flat barbs with barbules, something which was previously unknown.

What tricks can organic molecules be taught to help solve our planet’s biggest problems?

That’s the question driving Assistant Professor Richard Y. Liu ’15 as he pushes the frontiers of organic chemistry in pursuit of cleaner synthesis, smarter materials, and new ways to combat climate change.

Liu’s latest advance, detailed in a new paper in Nature Chemistry, harnesses the power of sunshine to trigger a particular variety of organic molecule. As described in the paper, these “photobases” then rapidly generate hydroxide ions that efficiently and reversibly trap CO₂.

This innovation in direct air capture marks a significant step toward scalable, low-energy solutions for removing greenhouse gases, Liu said. “What distinguishes this current work is the way we developed molecular switches to capture and release CO₂ with light. The general strategy of using light directly as the energy source is a new approach.”

Liu’s drive to understand the inner workings of organic chemistry date to his years at Harvard College. “I started out thinking I’d be a physicist,” he said. “But in my first semester, I realized I was much more captivated by the creative act of building molecules in the chemistry lab.”

Under the guidance of Ted Betley, Erving Professor of Chemistry, Liu uncovered a passion for organic synthesis, or designing and assembling complex structures atom by atom. “My mentor noticed that what really excited me wasn’t the iron complexes we were supposed to be working on,” Liu said. “It was the challenge of making the organic ligands themselves.”

Betley encouraged Liu to pursue these interests by working with a group led by Eric Jacobsen, Sheldon Emery Professor of Chemistry. There, Liu learned to think about molecules in new ways, to ask big questions, and to take big risks.

That ethos remained central during his doctoral work at the Massachusetts Institute of Technology, where Liu worked with chemist Stephen Buchwald to invent new copper and palladium catalysts that allow complex molecules to be prepared from convenient and readily available building blocks.

Now leading his own lab in the Department of Chemistry and Chemical Biology, Liu focuses on issues spanning the fields of organic, inorganic, and materials chemistry. His group’s research centers on organic redox platforms, metal-based catalysts for synthesis, and mechanistic studies that reveal how chemical transformations unfold.

“We’re looking at how to manipulate nonmetals — in molecules that are cheap, abundant, and tunable — to do chemistry traditionally reserved for metals,” Liu said.

Their work isn’t just theoretical; it’s built for the real world. Liu’s group is also developing new organic materials for energy storage and catalysis, as well as molecules that can capture and activate greenhouse gases. The recent direct air capture development was the product of a collaboration with Daniel G. Nocera, Patterson Rockwood Professor of Energy, and exemplifies the Liu lab’s pursuit of applicable solutions.

“Direct air capture is one of the most important emerging climate technologies, but existing methods require too much energy,” he said. “By designing molecules that use light to change their chemical state and trap CO₂, we’re demonstrating a path to a more efficient — and possibly solar-powered — future.”

Also responsible for the discovery is the lab’s interdisciplinary team of chemists, materials scientists, and engineers.

“We all speak the language of organic synthesis, but each person has an area of deeper expertise — from electrochemistry to sulfur chemistry to computational modeling,” Liu said. “This means we are able to generate new ideas at the intersections.”

Educating the next generation of scientists is core to that mission, he added. “Ultimately, the research we do here is kind of a platform for training and education,” Liu said. “The projects we do are ultimately for students to have a compelling and complete thesis that earns them their Ph.D. and serves as a springboard for what they’re going to do in the future.”

Yet the recent disruptions in federal funding present what Liu calls “an existential threat.” The photobase research was supported mainly by Lui’s CAREER award from the National Science Foundation. Its recent cancellation has jeopardized the project’s future while disrupting the work of trainees.

For now, bridge funding from the Salata Institute for Climate and Sustainability and the Faculty of Arts and Sciences has helped Liu and his group continue their research. Longer term, he hopes that the country will restore its investments in science.

“Research done at universities and institutions of higher learning will ultimately reap profits for all of society,” Liu said. “Our research is not driven by profits, but meant to make our discoveries and advancements publicly available for the world’s benefit.”

The Great Salt Lake once reached depths of up to 1,000 feet and spanned roughly 20,000 square miles, but today, it mostly resembles a parched wasteland. So, when signs of life suddenly began popping up across the drying playa, scientists were perplexed.

In the last several years, reed-covered mounds have appeared off the lake’s southeast shore. These densely vegetated oases must receive enough freshwater to sustain plant life, but experts weren’t sure where this resource was coming from. Researchers at the University of Utah are working to get to the bottom of this mystery, gradually uncovering a subsurface plumbing system that pumps fresh groundwater into the lake and its surrounding wetlands.

It appears to be “from a water resource that could be useful in the future, but we need to understand it and not overexploit it to the detriment of the wetlands,” co-researcher William Johnson, a professor of geology and geophysics at U of U, said in a university statement.

A worsening environmental crisis

Overexploitation has been one of the primary drivers of the Great Salt Lake’s decline, research shows. Humans have increasingly diverted freshwater from its feeder streams for agriculture and municipal use. As climate change has exacerbated evaporation in this Sun-baked region, the lake’s stressed tributaries have struggled to replenish rapid water loss.

If used responsibly, this potential new source of freshwater beneath the lakebed could help re-saturate lakebed crusts and reduce hazardous dust pollution blowing into nearby communities. With that goal in mind, Johnson and his colleagues have been using a suite of instruments and data—including piezometers, seepage meters, salinity profiles, and more—to locate underground freshwater deposits.

Probing beneath the surface

In February, he hired the Canadian firm Expert Geophysics to conduct aerial electromagnetic surveys over Farmington Bay, located on the lake’s southeastern shore. A helicopter with an airborne electromagnetic sensor hanging beneath it flew in a grid pattern over the bay, transmitting a frequency deep into the lakebed. A receiver then recorded the electromagnetic signals bounding back, gathering data that helps researchers locate freshwater deposits.

“It’ll give you a spectrum, basically, of magnetic fields, and we’ll use that data to create a 3D image of what’s under the earth,” Jeff Sanderson, a crew leader with Expert Geophysics, said in the U of U statement.

The wealth of data the researchers have gathered so far suggests a vast freshwater resource potentially extends thousands of feet beneath the cracked lakebed. It appears that immense pressure exerted on this aquifer allows water to rise up through the sediment, albeit very slowly. Thus, Johnson believes the mysterious mounds formed in places where this natural plumbing system delivers fresh groundwater to the surface.

The team has yet to publish its findings but presented preliminary data in July at the Geochemical Society’s 2025 Goldschmidt conference in the Czech Republic. Next, they will work to map this freshwater resource and determine its age and where it originated from. “The last thing I want to do is get this hyped as a water resource, but it’s very clear, and it’s under pressure,” Johnson said. “And in my mind, it could help mitigate any dust generation on the exposed playa.”