Ancient Martian Meteorite Teghaza 001 Identified as One of the Oldest Samples
NASA researchers have confirmed that the 800-gram meteorite Teghaza 001, found in Mali, dates to about 4.1 billion years ago and likely originated in Mars' southern highlands.
Scientists have determined that the pinkish, 800-gram meteorite recovered from a salt plain in Mali in 2022 is one of the oldest known rocks from Mars. Named Teghaza 001, the sample was initially classified as a common "shergottite" but further analysis revealed an age of roughly 4.1 billion years, matching the age of the previously oldest Martian meteorite, ALH84001.
Unlike ALH84001, which consists of a single mineral, Teghaza 001 contains a mix of igneous materials, including a notable amount of zircon. The mineral composition closely aligns with that of the southern highlands on Mars, allowing researchers to narrow its source to one of eleven specific locations on the planet.
Two NASA teams studied the meteorite. One examined its water content, publishing results in Science Advances in June 2026. The other, led by NASA-JPL scientist Yang Liu and Lee Saper of NASA’s Ames Research Center, reported their findings in Science on 29 October, highlighting both the meteorite’s age and the novel dating method employed.
"Right now, we are one of very few labs in the world able to perform this kind of age-dating, and the first to date such an ancient Martian meteorite," said Francois Tissot of Caltech.
The team used an in-situ rubidium-strontium dating technique that analyzes only a tiny sliver of the rock, preserving the bulk of the sample for future study.
"Our hope is to pave the way for dating even more Martian meteorites, or samples returned from other planets, their moons and asteroids," Tissot added.
The discovery provides new insight into the early formation of Mars' crust and its subsequent alteration by subsurface water.