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- Teghaza 001 is a meteorite that came from Mars.<\/strong> Prospectors found it in the Sahara Desert in 2022.<\/li>\n
- Analysis of this rock suggests Mars began to lose its water<\/strong> very early in its history.<\/li>\n
- Plus, it reveals Mars had a crust similar to granite<\/strong>, which is surprising given the planet lacks plate tectonics.<\/li>\n<\/ul>\n
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Teghaza 001, the oldest known Mars meteorite<\/h3>\n
Many pieces of Martian material have been ejected from the red planet and reached Earth as meteorites. And one of the more recently discovered Martian meteorites might be the oldest yet.<\/p>\n
That\u2019s what a team of scientists, led by the California Institute of Technology (Caltech), said on July 16, 2026. Prospectors found the meteorite \u2013 named Teghaza 001 \u2013 in the Sahara Desert in September 2022. And researchers have identified the piece of Mars\u2019 crust as being over 4.1 billion years old.<\/p>\n
The meteorite hints that the planet was already losing its water at that early stage in its life. Plus, it points to a granite-like crust on ancient Mars. That\u2019s surprising, as the formation of granite on Earth is associated with tectonic activity \u2026 and Mars lacks plate tectonics.<\/p>\n
The not-yet peer-reviewed paper is available as a preprint on the ESS Open Archive (April 14, 2026). Additional papers are also expected.<\/p>\n
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This meteorite, called Teghaza 001, \u201cwill revolutionize the way that we think about early Mars.\u201dLearn more: <\/p>\n
\u2014 Science Magazine (@science.org) 2026-07-21T22:40:01.528162083Z<\/p>\n<\/blockquote>\n
A view into Mars\u2019 past<\/h3>\n
Paper co-author Lee Saper is a geochemist at NASA\u2019s Jet Propulsion Laboratory (JPL). He gave a talk at the Goldschmidt geochemistry conference in Montreal, Canada, on July 14. He said that the meteorite:<\/p>\n
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\u2026 will revolutionize the way that we think about early Mars.<\/p>\n<\/blockquote>\n
And he\u2019s likely right.<\/p>\n
Teghaza 001 is only the second known Martian meteorite from the Martian crust in the earliest period of the planet\u2019s history. The other one is Allan Hills 84001. So now, scientists have two meteorites to work with instead of just one. Lydia Hallis, a planetary scientist at the University of Glasgow, said:<\/p>\n
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We\u2019ve doubled our old meteorites. There will be a lot of people, including me, who want to get a piece of this.<\/p>\n<\/blockquote>\n
So what does the meteorite show?<\/p>\n
Tegzaza is rich in both zircons and silicon. Zircon minerals contain tiny amounts of uranium. The uranium decays into lead over time. Since it decays at a known rate, scientists can use it to determine the age of the meteorite.<\/p>\n
If the zircon minerals melt or are exposed to fluids, though, then their \u201cclocks\u201d are reset to zero. This means that the meteorite might be even older than 4.1 billion years. Christopher Herd, a geologist at the University of Alberta, said:<\/p>\n
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There\u2019s more of a story to this rock than most other Martian meteorites.<\/p>\n<\/blockquote>\n
![\"Single](\"https:\/\/earthsky.org\/upl\/2026\/07\/Atoko-Point-rock-Perseverance-rover-Mars.jpg\")
View larger. | NASA\u2019s Perseverance rover found this unusual speckled white rock called Atoko Point last year. It has a granite-like appearance and contains feldspar, one of the key components of granite on Earth. Image via NASA\/ JPL-Caltech\/ ASU\/ MSSS\/ LiveScience.<\/figcaption><\/figure>\n Mars meteorite hints at granite-like crust on ancient Mars<\/h3>\n
But there was another surprise in the meteorite: it contained a lot of silicon. This hinted at granite-like rocks on ancient Mars. As Eva Scheller, a planetary scientist at Stanford University, noted:<\/p>\n
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It\u2019s very strange; we don\u2019t expect that.<\/p>\n<\/blockquote>\n
Scientists never expected Mars to have much granite since it lacks plate tectonics (the division of a planet\u2019s upper crust into multiple different pieces, or plates). On Earth, granite forms from cooling magma. And most of that magma is generated by the movement of tectonic plates. Meanwhile, most of Mars\u2019 crust is composed of solid basalt.<\/p>\n
But it\u2019s starting to look like Mars did once have at least some granite, or granite-like rock. Impacts from meteorites have exposed some deposits. And last year, the Perseverance rover discovered a rock outcrop, called Plankeholmane, that looks a lot like granite on Earth. It contained quartz, a key component of granite.<\/p>\n
And last year, the rover found an odd speckled white rock called Atoko Point that also appeared quite granite-like. It contained pyroxene and feldspar. Feldspar is also a component of granite on Earth.<\/p>\n
How was Mars able to produce such deposits without plate tectonics? Scientists don\u2019t know yet. This evidence also points to complex magma systems on early Mars, as does this other recent study.<\/p>\n
![\"Serious-looking](\"https:\/\/earthsky.org\/upl\/2026\/07\/Yang-Liu-Caltech-1.jpg\")
Yang liu at Caltech is the lead author of the new study about the Teghaza 001 meteorite from Mars. Image via Caltech.<\/figcaption><\/figure>\n When Mars dried up<\/h3>\n
The meteorite also provides valuable clues about past water on Mars. Both it and the Allan Hills meteorite show that Mars had more water early in its history. But they also indicate that Mars began to lose its water early on, as the planet\u2019s magnetic field disappeared and the atmosphere thinned and became much colder. Considering that these meteorites are at least 4.1 billion years old, and Mars \u2013 like Earth \u2013 formed some 4.5 billion years ago, this loss of water seems to have come in the planet\u2019s infancy.<\/p>\n
The clues come from the ratios of hydrogen in the meteorites. When Mars began to lose its water, the higher ratio of hydrogen \u2013 the primary component of water \u2013 to deuterium dropped. Super said:<\/p>\n
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This is the product of rapid hydrogen loss from the juvenile Martian atmosphere.<\/p>\n<\/blockquote>\n
The new analysis of Teghaza 001 has provided new clues about Mars\u2019 ancient past. And it also raises new questions. It will be interesting to see what else it and similar Mars meteorites reveal!<\/p>\n
Bottom line: A new analysis of the the oldest known Mars meteorite, Teghaza 001, reveals evidence for a granite-like crust and the start of the loss of water on early Mars.<\/p>\n
Source: Teghaza 001: An ancient Martian gabbroic diorite derived from previously unsampled Martian crust and mantle<\/p>\n
Via Science<\/p>\n
Read more: A famous Mars meteorite, now with nitrogen<\/p>\n
Read more: Methane in Mars meteorites = life?<\/p>\n
<\/div>\n
\n - Analysis of this rock suggests Mars began to lose its water<\/strong> very early in its history.<\/li>\n