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The study highlights minerals and textures that, on Earth, are often associated with microbial activity.

A rock sample collected by NASA’s Perseverance rover from an ancient riverbed in Jezero Crater may hold evidence of past microbial life on Mars. The discovery, described in a paper published in Nature, marks the closest scientists have come to identifying signs of life on the Red Planet.

The sample, called “Sapphire Canyon,” was extracted last year from a rock dubbed “Cheyava Falls” in the “Bright Angel” formation, a region of rocky outcrops bordering the ancient Neretva Vallis river valley.

“This finding by Perseverance, launched under President Trump in his first term, is the closest we have ever come to discovering life on Mars. The identification of a potential biosignature on the Red Planet is a groundbreaking discovery, and one that will advance our understanding of Mars,” said acting NASA Administrator Sean Duffy. “NASA’s commitment to conducting Gold Standard Science will continue as we pursue our goal of putting American boots on Mars’ rocky soil.”

Scientists stress that what Perseverance uncovered is a potential biosignature—defined as a substance or structure that might have a biological origin but requires further analysis to confirm. Sedimentary rocks at Bright Angel were found to be rich in clay, silt and organic carbon, as well as sulfur, oxidized iron and phosphorus—elements that, on Earth, often preserve signs of ancient life and provide energy for microbial metabolisms.

The rover’s PIXL and SHERLOC instruments first detected colourful markings on Cheyava Falls, a meter-long arrowhead-shaped rock. High-resolution scans revealed “leopard spots,” distinct mineral patterns formed by vivianite and greigite, compounds associated with decaying organic matter and microbial activity on Earth. These minerals can form through biological processes such as electron-transfer reactions but also via abiotic mechanisms like extreme heat or acidity. The Bright Angel rocks show no evidence of such conditions, leaving biological activity as a possible explanation.

“The combination of chemical compounds we found in the Bright Angel formation could have been a rich source of energy for microbial metabolisms,” added Perseverance scientist Joel Hurowitz of Stony Brook University, New York and lead author of the paper. “But just because we saw all these compelling chemical signatures in the data didn’t mean we had a potential biosignature. We needed to analyze what that data could mean.”

The study’s findings are particularly striking because the rocks are among the youngest sedimentary formations studied by the mission, suggesting Mars may have remained habitable longer than previously thought. Perseverance project scientist Katie Stack Morgan emphasized the importance of scientific rigor in evaluating astrobiological claims. “Getting such a significant finding into a peer-reviewed publication is a crucial step,” she said. “While abiotic explanations are less likely, we cannot rule them out.”

To guide interpretation, researchers apply frameworks such as the CoLD scale and Standards of Evidence, which help assess how much confidence can be placed in data suggesting life beyond Earth.

Since its landing in February 2021, Perseverance has collected 27 rock cores, including Sapphire Canyon, while also monitoring the Martian environment and testing spacesuit materials for future crewed missions. Operated by NASA’s Jet Propulsion Laboratory and managed through Caltech, the rover is part of the agency’s broader Mars Exploration Program.

Nicky Fox, associate administrator of NASA’s Science Mission Directorate, said the discovery was the result of careful mission planning and execution. “With the publication of this peer-reviewed result, NASA makes this data available to the wider science community for further study to confirm or refute its biological potential,” she said.

The Northrop Grumman Cygnus cargo ship loaded with 11,000 pounds of experiments and supplies for the International Space Station will not dock tomorrow morning as planned. Launched on Sunday, the NG-23 spacecraft experienced propulsion anomalies today as it raised its orbit to match that of the ISS. NASA and Northrop Grumman are assessing what steps are needed next. A new arrival date is to be determined.

NG-23 lifted off on time Sunday evening at 6:11 pm ET aboard a SpaceX Falcon 9 from Cape Canaveral Space Force Station, FL.

Liftoff! pic.twitter.com/1FdkcobmIR

— SpaceX (@SpaceX) September 14, 2025

All apparently proceeded as expected until this morning when the NG-23 engines “stopped earlier than planned during two burns designed to raise the orbit” in preparation for rendezvous with the ISS according to NASA. The reasons aren’t clear yet as “flight controllers evaluate an alternate burn plan.”

This is the first launch of Northrop Grumman’s new XL version of Cygnus that can deliver 33 percent more cargo.

Although this is designated NG-23, it is only the 22nd Cygnus capsule to be launched. NG-22 was damaged during shipping via boat from its manufacturer, Thales Alenia Space, in Italy to Florida. Northrop Grumman plans to fly it to the ISS once it’s repaired.

Cygnus does not dock with the ISS, but is captured by the Canadarm2 robotic arm and installed — or berthed — onto a docking port.

NASA astronaut Jonny Kim was to be at Canadarm2’s controls tomorrow morning to capture it at 6:35 am ET, but that will have to wait.

Last Updated: Sep 16, 2025 11:11 pm ET

When most of us think about what shaped our planet, we probably picture volcanoes, earthquakes, and huge continents slowly drifting apart (or back together again) over millions or billions of years. We also know meteorite impacts were important; our crater-packed Moon is clear evidence of that.

But what if Earth’s geological story was also written further afield in the stars – specifically, in the spiral arms of our home galaxy, the Milky Way?

That’s the bold idea that has been resonating behind some recent research that links astrophysics with geology. So far, these controversial ideas have been based on models, limited by gaps in Earth’s geological record and the uncertainties in our Solar System’s galactic path.

But our new study, published this week in Physical Review Research, takes a different approach by comparing maps of hydrogen gas in the Milky Way with chemical fingerprints in ancient crystals on Earth. The findings support the view that Earth’s crust may have been influenced by the Solar System’s journey around the galaxy.

Reading the galaxy through hydrogen

Astronomers often use neutral hydrogen, the simplest atom of one proton and one electron, as a cosmic marker.

This atomic hydrogen emits radio waves at a wavelength of 21 centimetres, which cut through the dust and gas that obscure much of the Milky Way from our view. These emissions, from higher density regions of hydrogen, reveal the sweeping spiral arms of the galaxy, even when visible-light telescopes cannot.

The spiral arms aren’t solid structures. Instead, they’re density waves – like traffic jams of stars, gas and dust that move around the galactic disc more slowly than individual stars themselves.

As the Solar System orbits the galactic centre faster than the arms, it periodically overtakes them, roughly every 180–200 million years. Passing through a spiral arm could increase the number of comets and asteroids striking Earth.

Zircon crystals: tiny time capsules

How can we know if Earth really felt the consequences of these galactic encounters?
The answer may lie in zircon, a hardy mineral commonly found in Earth’s crust, that can survive for billions of years.

Zircon crystals form in magmas and are like tiny time capsules. Not only can they be dated, but they also carry chemical clues about what Earth was like at the moment they grew.

Inside these crystals, the oxygen atoms occur in slightly different forms, called isotopes, that have the same chemistry but different masses. These isotopes act as tracers, showing whether the magma came from deep inside Earth or had contact with surface water.

As the Solar System travels around the galaxy, it passes through spiral arms where hydrogen gas is more concentrated. If there is unusual variability in zircon oxygen isotopes at the times of high atomic hydrogen density, then this suggests something disrupted the normal balance of crust formation on Earth.

Matching Earth’s rocks with galactic maps

The new study directly compared this zircon isotope record with radio frequency-measured hydrogen density along the Solar System’s galactic orbit. The result? Striking correlations.

Periods when the Solar System passed through spiral arms – regions with denser hydrogen – line up with spikes in zircon oxygen variability.

In other words, Earth’s crust seemed more “chaotic” at the same times the Solar System was embedded in star-forming arms of the Milky Way.

A galactic fingerprint on Earth’s crust

What could explain this connection?

One idea is that when the Solar System moves through a spiral arm, it can shake up the distant icy region of space known as the Oort Cloud, a giant reservoir of comets far beyond Pluto.

Some of these comets may then hurtle toward Earth.

Each impact delivers enormous energy – enough to melt rock, trigger geological upheaval and leave lasting marks in the planet’s crust.

Crucially, this record is preserved over billions of years, much longer than the impact craters we can still see on Earth, which are often erased by erosion or plate tectonics.

Zircons may therefore offer a deep-time archive of galactic influences that we can’t observe directly through astronomy.

A cosmic connection

If Earth’s geology really responds to the rhythms of the galaxy, it expands our view of what drives planetary evolution. It suggests that to fully understand Earth, we must look beyond it, to the vast structures of the Milky Way that periodically reshaped our Solar System’s environment.

Recognising astrophysical fingerprints in planetary geology could provide new clues about crustal growth, habitability, and even the emergence of life.

Of course, caution is warranted. Correlation doesn’t always mean causation, and disentangling the effects of galactic arm crossings from Earth’s internal processes is tricky. But the emerging evidence is compelling enough to take seriously.

For now, zircon crystals, tiny grains often smaller than a sand particle, are helping us glimpse a connection between Earth and the cosmos.