Ancient Martian Meteorite Teghaza 001 Offers New Clues on Early Mars Water Activity
Scientists say the 800-gram Teghaza 001 meteorite, found in the Sahara, is among the oldest Martian rocks on Earth and reveals details of early crust formation and water interaction on Mars.
A rose-coloured rock recovered from the Sahara Desert in 2022 has been identified as a Martian meteorite that formed more than 4.1 billion years ago, making it one of the oldest such samples found on Earth, NASA researchers reported. Named Teghaza 001 after the Mali salt plain where it was discovered, the 800-gram specimen may help scientists reconstruct the early Martian surface and assess how water interacted with rocks billions of years ago.
The findings were presented in a paper published in Science on Thursday. Lead author Yang Liu of NASA’s Jet Propulsion Laboratory said the meteorite’s unique texture and mineral mix became evident only after detailed examination, and a reviewer described the sample as a “Rosetta Stone for Mars.”
Teghaza 001 is notable for its age, texture and volcanic mineral assemblage, placing it among the three oldest Martian meteorites known. Unlike the nearly single-mineral ALH84001 and the younger “Black Beauty,” Teghaza 001 contains a blend of volcanic minerals that record how Mars’ crust cooled and later interacted with underground water. Its mineral composition matches features observed in the cratered southern highlands by the Mars Reconnaissance Orbiter, though its exact source region on Mars remains uncertain.
Co-author Lee Saper highlighted that the rock provides a sample from a previously unsampled Martian crustal region, preserving evidence of water-rock interaction and possibly traces of the ancient Martian atmosphere during a period of water loss. A related study in Science Advances examined the meteorite’s water content, further illuminating early surface processes.
Initial identification as Martian was based on oxygen-isotope fingerprints measured by researchers at the University of New Mexico. Subsequent analysis revealed zircon crystals that allow precise age dating. Using a technique developed by a Caltech team led by Francois Tissot, the researchers examined individual mineral grains on the rock’s surface, preserving most of the sample for future work.
Age-dating results indicated that water altered the meteorite around 4.1 billion years ago, implying the rock itself formed even earlier. The combined isotopic, textural and chemical data suggest that early Mars may have experienced a more active water cycle than previously thought.