SAHARA DESERT — A reddish rock found in the Sahara Desert in 2022 formed in the crust of Mars at least 4.1 billion years ago, scientists reported on Thursday, October 29, 2026, making it one of the oldest Martian meteorites ever found on Earth and a rare surviving witness to a time when the Red Planet was warmer, wetter, and far more Earth-like than the cold, dry world it is today.
The meteorite, named Teghaza 001 after the salt plain in Mali where it was discovered, is described in a new study published in the journal Science. Its chemistry carries fresh evidence that liquid water was percolating through the Martian crust more than 4.1 billion years ago, strengthening the case that early Mars had the ingredients and conditions that could have supported microbial life — without, the researchers stress, proving that life ever existed there.
Illustration: A reddish Martian meteorite in the Sahara Desert, where Teghaza 001 was found in 2022 near the Malian village of Bir Chali.
What Happened
According to Reuters, which reported the study on October 29, Teghaza 001 was discovered in eight pieces in the desert roughly 21 miles (34 kilometers) from the Malian village of Bir Chali. The largest chunk is about the size of a fist, and the meteorite weighs nearly 2 pounds (about 800 grams), according to NASA's Jet Propulsion Laboratory (JPL), which funded the research.
The study's lead author, planetary scientist Yang Liu of JPL, called the rock "a witness to a time when Mars was likely warmer and wetter than it has been for most of its history." The researchers dated the meteorite using zircon crystals it contains, measuring the decay of uranium into lead over time — a technique that put its formation at at least 4.1 billion years ago, when the solar system itself was only about 400 million years old.
Teghaza 001 is a coarse-grained igneous rock known as gabbro. Its main minerals are feldspar and pyroxene, and its chemistry shows it formed from magma originating deep in the Martian mantle before slowly cooling and crystallizing in the planet's outermost layer, the crust. As it cooled, the study found, it interacted with water — a finding the Maine Mineral & Gem Museum, which holds part of the meteorite in its collection, described as evidence of reactions with water-rich fluids before the rock was ejected from Mars.
That water evidence is the heart of the discovery. Isotopes of oxygen and hydrogen in the meteorite show that water was percolating down into the deeper crust, as happens on Earth, and mixing with molten rock from the mantle. "Multiple lines of evidence in Teghaza 001 suggest Mars' surface had water at more than 4.1 billion years ago," Liu said, as reported by Reuters, pointing to hydrogen isotopes in phosphate and oxygen isotopes in minerals and bulk samples.
Background
Mars today is cold, dry, and desolate. But extensive evidence gathered over decades indicates that billions of years ago, water flowed across its surface in rivers and lakes, and an ocean may have covered parts of the northern hemisphere. The question that has driven Mars science ever since is how long those habitable conditions lasted — and whether anything ever lived in them.
Martian meteorites are, for now, the only samples of Mars that scientists can study in laboratories on Earth. About 435 meteorites from Mars are known, according to Reuters and JPL, and most of them are far younger than the ancient terrain that covers much of the planet's surface. Only three Martian meteorites, including Teghaza 001, date to the planet's early history, which makes each one disproportionately valuable.
One of the other two is the famous Allan Hills 84001 meteorite, discovered in Antarctica in 1984. It was initially assessed as being about 4.5 billion years old but has more recently been determined to have a similar age to Teghaza 001 — and according to the new study, Teghaza 001 is likely the older of the two. Scientific American, reporting the study, quoted Liu as saying: "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."
Teghaza 001's backstory is dramatic in its own right. As Liu described it to Reuters, the rock "was blasted by an impact from the surface of Mars and was flying through space until its path crossed that of Earth. It then entered the atmosphere as a meteor and survived as a meteorite by landing in the Sahara." When exactly it landed on Earth is not known. Its chemistry suggests it may have originated in Mars' southern highlands, possibly from near Hellas Basin, one of the largest impact craters in the solar system.
Illustration: Scientists studying a sample of Teghaza 001 in a laboratory, where uranium-lead dating of its zircon crystals revealed its age.
Why It Matters
The discovery matters because it pushes direct evidence of water on Mars further back in time than almost any other sample allows. Water is considered a key ingredient for life, and a rock that records water moving through the crust more than 4.1 billion years ago shows that the ingredients for habitability were present almost from the beginning of Mars' history as a planet.
But the researchers are careful about what the rock does and does not prove. "The findings lend support to the idea that early Mars had the necessary ingredients and conditions to harbor life, but do not directly answer the question of whether there was life on Mars," said planetary scientist and study co-author Lee Saper of NASA's Ames Research Center and the BAER Institute, as reported by Reuters. Saper described the meteorite as "a snapshot in time that shows how a wetter early Mars with a thick atmosphere could have supported habitable conditions but that these conditions were waning rapidly over the first billion years or so of Mars' existence, trending towards its currently dry and inhospitable environment."
Teghaza 001 is also distinct from every other Martian meteorite studied so far. The Maine museum notes that its composition, mineralogy, and texture are distinct from other known Martian meteorites, and its analysis points to a geochemically distinct source in Mars' mantle. Researchers at the University of New Mexico, who first examined samples recovered from the Sahara, noticed unusual textural and compositional features, including domains with high levels of manganese oxide — a compound that rovers on Mars are searching for as an indicator of environments conducive to life. One reviewer of the new paper went further, calling the meteorite a "Rosetta Stone for Mars," according to JPL.
The finding also sharpens a long-standing puzzle: how the evolution of Mars diverged from Earth's. Earth, Mars, and the solar system's other planets formed roughly 4.5 billion years ago, and life was beginning to take hold on Earth around the time Teghaza 001 was forming. "Martian meteorites are our only samples from Mars, forming our basis for understanding the formation and differentiation of early Mars and allowing us to evaluate in laboratories whether ancient Mars could have supported habitable conditions," Liu said. "The detailed information we can extract from these meteorite samples complements and validates our exploration of Mars using satellites, landers and rovers."
What Happens Next
Scientists say Teghaza 001 will keep yielding results for years. The Science paper is described by JPL as an initial characterization of the meteorite, and what researchers learn from future studies could help answer many questions, including how water and rocks interacted on ancient Mars. A separate paper published in Science Advances in June 2026 already detailed the meteorite's water content, offering another look at how water shaped the early planet's surface.
Part of the meteorite is now in the collection of the Maine Mineral & Gem Museum in Bethel, Maine, where visitors can explore specimens that tell the story of Earth and the wider solar system. Further laboratory work on Teghaza 001 — including more precise dating, mineral analysis, and comparison with data from rovers and orbiters — is expected to refine estimates of where exactly on Mars it came from and how long its watery chapter lasted.
Illustration: An impact blasts rock off the surface of Mars, beginning a journey through space that ends with a meteorite landing on Earth.
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FAQ
What is Teghaza 001?
Teghaza 001 is a Martian meteorite found in eight pieces in the Sahara Desert in Mali in 2022, near the village of Bir Chali. It is a reddish, coarse-grained igneous rock called gabbro, weighing nearly 2 pounds (about 800 grams), and it is one of roughly 435 meteorites from Mars known on Earth.
How old is Teghaza 001?
At least 4.1 billion years old. Researchers dated it by measuring the decay of uranium into lead in zircon crystals contained in the rock. It is one of only three Martian meteorites known to date to Mars' early history, and the new study suggests it is likely older than the famous Allan Hills 84001 meteorite found in Antarctica in 1984.
Does Teghaza 001 prove there was life on Mars?
No. The study provides evidence that liquid water was percolating through the Martian crust more than 4.1 billion years ago, which supports the idea that early Mars had conditions that could have supported microbial life. The researchers explicitly state that the findings do not directly answer whether life ever existed on Mars.
How did a rock from Mars end up in the Sahara?
According to lead author Yang Liu, an impact blasted the rock off the surface of Mars. It then traveled through space until its path crossed Earth's, entered the atmosphere as a meteor, and survived landing in the Sahara Desert. Scientists do not know when it landed on Earth.
Where can the meteorite be seen, and what happens next?
Part of Teghaza 001 is in the collection of the Maine Mineral & Gem Museum in Bethel, Maine. Further laboratory studies are expected to refine where on Mars it originated — possibly the southern highlands near Hellas Basin — and how water and rocks interacted on ancient Mars, complementing data from satellites, landers, and rovers.
Sources
- Reuters, "Martian meteorite found in the Sahara is 4.1 billion years old," October 29, 2026.
- NASA Jet Propulsion Laboratory, "NASA-funded Study Details One of Oldest Mars Meteorites Ever Found," October 2026.
- Scientific American, "Oldest known Mars rock is a 'Rosetta stone' for the Red Planet's watery past," October 2026.
- Maine Mineral & Gem Museum, "Ancient Martian Meteorite in Maine Mineral & Gem Museum Collection Offers Clues to Mars' Early History," October 2026 (study in Science, doi:10.1126/science.adz5646).
- Phys.org / University of New Mexico, "Rare 4.1-billion-year-old Martian meteorite reveals clues to planet's ancient past," October 2026.
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