Martian meteorite records crust formed at least 4.1 billion years ago

Teghaza 001 formed at least 4.1 billion years ago, making it one of the most ancient Martian meteorites found on Earth, according to a study published Oct. 29, 2026, in Science. The researchers describe it as a sample of early Martian crust formed from magma with a geochemically distinct mantle source.

The meteorite was found in 2022 on the Teghaza salt plain in Mali’s Sahara. Its recovered pieces have a combined mass of about 800 grams and are held by the Maine Mineral & Gem Museum.

Teghaza 001 is an igneous rock: it formed as magma cooled and solidified. The study describes it as slowly cooled, with a mix of igneous minerals. It is a sample of crust formed from material originating in the mantle, not a direct sample of the mantle itself.

The researchers also report that oxygen-18-enriched fluids altered the rock before it was ejected from Mars. Their evidence includes altered minerals and oxygen-isotope measurements of both the whole rock and individual minerals. NASA’s Jet Propulsion Laboratory places this water-related alteration at around 4.1 billion years ago. That is an approximate estimate for the fluid interaction, separate from the study’s minimum age for the rock’s formation.

How Teghaza compares with other Martian meteorites i

NASA JPL says roughly 435 Martian meteorites are known, and places Teghaza 001 among the three most ancient found on Earth. The comparisons help show what makes this sample distinctive:

Using the rounded reported ages, Teghaza 001’s minimum age is about 2 billion years greater than Black Beauty’s. Its mineral mix also provides a different record from ALH84001: NASA JPL says Teghaza’s minerals reflect crust formation from cooling magma followed by alteration by subsurface water.

The exact place on Mars where Teghaza 001 began remains unknown. NASA JPL reports 13 locations with mineralogy and chemistry that match the meteorite; those are possible sources, not confirmed origins. The sample therefore gives researchers material to study early crust and water-rock interaction without pinpointing a particular Martian site.

Water evidence is not evidence of life i

Does the evidence of water mean life existed on Mars? No. The study reports geological evidence that water-rich fluids reacted with the rock; it does not establish that life existed. Water-rock interaction and evidence of life are different findings.

Researchers describe their work as an initial characterization, and NASA JPL says further study is needed. For now, the meteorite’s value is as a rare physical sample of ancient crust and its later interaction with water—not as proof of a particular source location or of life on Mars.