NASA’s Perseverance rover has bagged its first hint of ancient microbes on Mars.

“We’re not able to say that this is a sign of life,” says Perseverance deputy project scientist Katie Stack Morgan of NASA’s Jet Propulsion Lab in Pasadena, Calif.  “But this is the most compelling sample we’ve found yet.”

The rover drilled up the sample on July 21 from a reddish rock, dubbed Cheyava Falls after a feature at the Grand Canyon. It is the first piece of Mars that Perseverance has examined that contains organic molecules, the building blocks of life, project scientist Ken Farley of Caltech reported July 25 at the 10th International Conference on Mars in Pasadena. More

Flashes of CreationPaul HalpernBasic Books, $30

The Big Bang wasn’t always a sure bet. For several decades in the 20th century, researchers wrestled with interpreting cosmic origins, or if there even was a beginning at all. At the forefront of that debate stood physicists George Gamow and Fred Hoyle: One advocated for an expanding universe that sprouted from a hot, dense state; the other for a cosmos that is eternal and unchanging. Both pioneered contemporary cosmology, laid the groundwork for our understanding of where atoms come from and brought science to the masses.

In Flashes of Creation, physicist Paul Halpern recounts Gamow’s and Hoyle’s interwoven stories. The book bills itself as a “joint biography,” but that is a disservice. While Gamow and Hoyle are the central characters, the book is a meticulously researched history of the Big Bang as an idea: from theoretical predictions in the 1920s, to the discovery of its microwave afterglow in 1964, and beyond to the realization in the late 1990s that the expansion of the universe is accelerating.

Although the development of cosmology was the work of far more than just two scientists, Halpern would be hard-pressed to pick two better mascots. George Gamow was an aficionado of puns and pranks and had a keen sense of how to explain science with charm and whimsy (SN: 8/28/18). The fiercely stubborn Fred Hoyle had a darker, more cynical wit, with an artistic side that showed through in science fiction novels and even the libretto of an opera. Both wrote popular science books — Gamow’s Mr Tompkins series, which explores modern physics through the titular character’s dreams, are a milestone of the genre — and took to the airwaves to broadcast the latest scientific thinking into people’s homes.

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“Gamow and Hoyle were adventurous loners who cared far more about cosmic mysteries than social conventions,” Halpern writes. “Each, in his own way, was a polymath, a rebel, and a master of science communication.”

While the Big Bang is now entrenched in the modern zeitgeist, it wasn’t always so. The idea can be traced to Georges Lemaître, a physicist and priest who proposed in 1927 that the universe is expanding. A few years later, he suggested that perhaps the cosmos began with all of its matter in a single point — the “primeval atom,” he called it. In the 1940s, Gamow latched on to the idea as way to explain how all the atomic elements came to be, forged in the “fireball” that would have filled the cosmos in its earliest moments. Hoyle balked at the notion of a moment of creation, convinced that the universe has always existed — and always will exist — in pretty much the same state we find it today. He even coined the term “Big Bang” as a put-down during a 1949 BBC radio broadcast. The elements, Hoyle argued, were forged in stars.

As far as the elements go, both were right. “One wrote the beginning of the story of element creation,” Halpern writes, “and the other wrote the ending.” We now know that hydrogen and helium nuclei emerged in overwhelming abundance during the first few minutes following the Big Bang. Stars took care of the rest.

Halpern treats Gamow and Hoyle with reverence and compassion. Re-created scenes provide insight into how both approached science and life. We learn how Gamow, ever the scientist, roped in physicist Niels Bohr to test ideas about why movie heroes always drew their gun faster than villains — a test that involved staging a mock attack with toy pistols. We sit in with Hoyle and colleagues while they discuss a horror film, Dead of Night, whose circular timeline inspired their ideas about an eternal universe.

In the mid-20th century, two astronomers emerged as spokesmen for dueling ideas about the origin of the cosmos. George Gamow (left) was a passionate defender of the Big Bang theory, arguing that the universe evolved from a hot, dense state. Fred Hoyle (right) upheld the rival “steady state model,” insisting that the universe is eternal and unchanging.From left: AIP Emilio Segrè Visual Archives, George Gamow Collection; AIP Emilio Segrè Visual Archives, Clayton Collection

And Halpern doesn’t shy away from darker moments, inviting readers to know these scientists as flawed human beings. Gamow’s devil-may-care attitude wore on his colleagues, and his excessive drinking took its toll. Hoyle, in his waning decades, embraced outlandish ideas, suggesting that epidemics come from space and that a dinosaur fossil had been tampered with to show an evolutionary link to birds. And he went to his grave in 2001 still railing against the Big Bang.

Capturing the history of the Big Bang theory is no easy task, but Halpern pulls it off. The biggest mark against the book, in fact, may be its scope. To pull in all the other characters and side plots that drove 20th century cosmology, Gamow and Hoyle sometimes get forgotten about for long stretches. A bit more editing could have sharpened the book’s focus.

But to anyone interested in how the idea of the Big Bang grew — or how any scientific paradigm changes — Flashes of Creation is a treat and a worthy tribute to two scientific mavericks.

Buy Flashes of Creation from Bookshop.org. Science News is a Bookshop.org affiliate and will earn a commission on purchases made from links in this article. More

Sand on Earth is continuously being created by the slow erosion of rocks. But on Mars, violent asteroid impacts may play an important role in making new sand.

As much as a quarter of Martian sand is composed of spherical bits of glass forged in the intense heat of impacts, a new study shows. Since windblown sand sculpts the Martian landscape, this discovery reveals how asteroid impacts contribute to shaping Mars, even long after the collisions occur, Purdue University planetary scientist Briony Horgan and colleagues suggest. The team will present their results August 18 at the 85th Annual Meeting of the Meteoritical Society in Glasgow, Scotland.

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Using data collected by spacecraft orbiting Mars, Horgan and collaborators looked at different wavelengths of visible and infrared light reflected from the planet’s surface to determine the minerals present in Martian sand. The team found signatures of glass all over the planet, particularly at higher latitudes.

One explanation for all that glass is volcanic eruptions, which are known to produce glass when magma mixes with water. But the most glass-rich swath of Mars — the planet’s northern plains — is conspicuously bereft of volcanoes, the researchers note. That rules out volcanic eruptions as the culprit in that location and instead suggests that far more cataclysmic events — asteroid impacts — might be involved.

That’s a plausible argument, says Steven Goderis, a geochemist at the Vrije Universiteit Brussel in Belgium who was not involved in the research. “Often Mars is seen as a volcanic planet. But there’s also a very strong impact component, and this is often overlooked.”

When an asteroid moving at several kilometers per second slams into a rocky planet like Mars, the energy of the event melts nearby rocks and launches them skywards. That molten shrapnel fragments and produces sand grain–sized pieces that are roughly spherical. Those bits of glass — called impact spherules — eventually rain back onto the planet (SN: 3/31/21).

Martian sand, imaged by NASA’s Phoenix Mars Lander, contains dark, spherical grains that were most likely created by asteroid impacts.Briony Horgan/ICL/UA/JPL/NASA

Over the last 3 billion years, asteroid impacts could have plausibly blanketed the surface of Mars in a layer of impact spherules roughly half a meter thick, Horgan and her colleagues calculate. All that material added to the sand on Mars that formed through normal erosion. “Impacts helped supply sand to the surface continuously over time,” Horgan says.

Scientists might have the opportunity to analyze Martian impact spherules in the future. NASA’s Perseverance rover is currently storing samples of Martian sand and rocks for eventual return to Earth (SN: 9/10/21). That’s exciting, Horgan says. “The record of all this is in the sand.” More

Researchers may have figured out how a crucial ingredient that cells need to produce energy could form in deep space.

Calculations and lab experiments suggest that glyceric acid can arise from radiation blasting carbon dioxide and ethylene glycol in interstellar clouds, researchers report in the March 15 Science Advances.

The study is “a great start to understand how these molecules are formed in space,” says Anthony Remijan, an astrochemist at the National Radio Astronomy Observatory in Charlottesville, Va., who was not involved in the research. The finding suggests that “if you put the right mixture together, in the right conditions, maybe you can even afford more complex molecules in space,” he says. More

Scientists have coaxed one of the universe’s most stubborn elements into a new compound.

Formed under intense pressures, the newly discovered compound packs helium atoms into crystalline iron, researchers report February 25 in Physical Review Letters. The compound joins a short list of materials that incorporate the normally unreactive element and suggests that helium from the early solar system could be stored in the iron that makes up Earth’s core.

Helium is one of the least reactive elements on the periodic table. Like the other noble gases, helium doesn’t gain or lose electrons easily and so does not normally form chemical compounds. But under extremely high pressures, helium can interact with a few other elements, including nitrogen and sodium — and now iron, research shows.

An iron-helium compound, shown here in artificial color using a technique called secondary ion mass spectrometry, forms under high temperature and pressure. Blue and black areas mark the background, while the orange and red area represents the sample. ©2025 Hirose et al. CC-BY-ND

To make the new iron compound, physicist Kei Hirose of the University of Tokyo and his colleagues squeezed iron and helium together in a diamond anvil cell, a high-pressure device that subjected the elements to pressures greater than 50,000 Earth atmospheres and temperatures above 1,000 degrees Celsius. This compression formed crystals containing both iron and helium.

The volume of the crystal formed was larger than that of a crystal of pure iron at the same pressure, the team found. The researchers attributed this increase to helium ions packing into interstitial sites, the tiny spaces between iron atoms in the crystal. But the helium atoms don’t bond directly to iron — they’re too unreactive, even at extreme conditions. More