NASA-funded study details one of oldest Mars meteorites ever found

NASA-funded scientists found that a rose-colored meteorite discovered in the Sahara Desert in 2022 formed more than 4.1 billion years ago. The nearly 2-pound (800-gram) rock, named Teghaza 001 after the salt plain in Mali where it was discovered, is one of roughly 435 meteorites from Mars.

Researchers published an initial characterization of Teghaza 001 Thursday in Science. According to NASA, the study provides a rare snapshot of Mars' ancient crust and formation. Future studies could help explain how water and rocks interacted on ancient Mars.

Teghaza 001 is one of the three most ancient Martian meteorites found on Earth. Its mix of igneous minerals records how Mars' crust formed from cooling magma before subsurface water altered it. Another ancient meteorite, ALH84001, is composed almost entirely of one mineral. A third meteorite, nicknamed Black Beauty, formed about 2.1 billion years ago and contains small volcanic rock fragments.

The meteorite's distinctive mineralogy matches observations from NASA's Mars Reconnaissance Orbiter in Mars' cratered southern highlands. Researchers identified several possible locations on Mars that match Teghaza 001's mineralogy and chemistry. The exact place where the meteorite originated will remain unknown.

Researchers at the University of New Mexico identified Teghaza 001 as Martian by matching its oxygen isotopes with those of other Martian meteorites. The team later found zircon crystals that could be used to date the rock. Caltech coauthor Francois Tissot applied in-situ rubidium-strontium age-dating to individual mineral grains in a piece smaller than a fingernail.

NASA said the results showed that Martian water altered Teghaza 001 around 4.1 billion years ago. The meteorite suggests it formed even earlier and preserves evidence of interactions between water, rock and possibly the Martian atmosphere. Researchers said further study of the meteorite and related papers could reveal more about early Mars.