This Rosy Stone Spotted in the Sahara Turned Out to Be a 4.1-Billion-Year-Old Meteorite From Mars, One of the Oldest Ever Found

Martian samples this old are extremely rare and offer clues about the Red Planet’s youth. This meteorite further hints that our celestial neighbor was once a watery world, suggesting it could’ve had the conditions to host life

Margherita Bassi | Daily Correspondent

October 30, 2026 2:42 p.m.

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In 2022, a strange, rosy stone was discovered in the Sahara Desert. Now, scientists have found that the nearly two-pound object is a Martian meteorite made of rock that formed at least 4.1 billion years ago. The findings, published October 29 in the journal Science, mean it’s one of the oldest known samples of Mars and can help researchers better understand what the Red Planet was like in its youth.

“We’re holding a piece of a rock that’s dated even before the oldest Earth rock—a piece of Mars that’s so ancient, it existed when life had just started on Earth,” study co-author Yang Liu, a geologist at NASA’s Jet Propulsion Laboratory, tells Scientific American’s Mary Randolph.

Scientists know of more than 400 Martian meteorites. These pieces were ejected from the Red Planet when impactors hit the celestial body. The debris was flung toward Earth, passed through our atmosphere without completely burning up and then landed on the planet’s surface. Previously, only two meteorites provided snapshots of a young Mars, which formed around 4.5 billion years ago: Allan Hills 84001, dated at 4.1 billion years old, and Northwest Africa 7034, which contains fragments dated at more than 4.3 billion years old.

To figure out the age of the Sahara meteorite, called Teghaza 001, Liu and colleagues looked at the zircon crystals within it, which contain the element uranium. Researchers often date rocks by examining the decay of uranium into lead. The team also analyzed different forms of the elements rubidium and strontium in the meteorite, which yielded a similar age estimate.

Teghaza 001’s age isn’t its only special feature. Unlike the other two oldest known Martian meteorites, the rosy space rock’s composition of volcanic minerals reveals that the fragment was originally a bunch of magma. It cooled and hardened into part of Mars’ outermost layer, the crust, and was further transformed by underground water, according to chemical analyses. This evidence of the meteorite’s past interactions with water joins a growing body of research indicating that Mars—now a dry, dusty world—was once a much wetter place.

“When you add a third sample, and its geochemistry is really unique compared to the other samples that we have, it lets us see a different part of Mars’ ancient history in terms of what the mantle looked like and what the different mantle sources were on Mars,” says study co-author Alicia Cruz-Uribe, a geochemist at the University of Maine, in a statement.

Mars’ past watery environment is one reason that researchers think the planet could have hosted life long ago, since all known organisms need water.

“The findings lend support to the idea that early Mars had the necessary ingredients and conditions to harbor life,” study co-author Lee Saper, a geochemist at NASA’s Ames Research Center and the Bay Area Environmental Research Institute, tells Reuters’ Will Dunham. However, they “do not directly answer the question of whether there was life on Mars.”

The researchers say Teghaza 001 likely came from Mars’ Noachian southern highlands, since the meteorite’s chemical makeup matches what NASA’s Mars Reconnaissance Orbiter has observed there. They’ve identified 13 possible origin locations that align with the meteorite’s composition, according to a NASA statement.

Still, there are many unanswered questions about the meteorite, Arya Udry, a planetary scientist at the University of Nevada, Las Vegas, who did not participate in the study, tells Scientific American. And to really comprehend Mars’ evolutionary history, scientists are going to need more than these pieces of the Red Planet that end up on Earth by chance, she adds.

“Mars is a complex planet, and this meteorite is really cool, but we don’t know exactly where it came from, so this is really another example of why we need to bring back samples.”

Margherita Bassi is a freelance journalist and trilingual storyteller. Her work has appeared in publications including BBC Travel, Discover magazine, Live Science, Atlas Obscura and Hidden Compass.