4.1-billion-year-old Mars rock found in the Sahara hints at a wetter young planet
A rose-coloured rock picked up in the Sahara Desert in 2022 has turned out to be a piece of Mars more than 4.1 billion years old. Named Teghaza 001 after the salt plain in Mali where it was found, it is one of the oldest Mars meteorites known.
The findings were published on 29 October in the journal Science. The study was led by Yang Liu of NASA’s Jet Propulsion Laboratory, with researchers at the University of New Mexico, Caltech and other US universities.
The meteorite weighs about 800 grams, or nearly two pounds, and is made up of eight fragments. It is one of about 435 known Mars meteorites. Most are much younger, often only a few hundred million years old.
Tiny zircon crystals inside the rock allowed the team to date it to at least 4.1 billion years. It formed from cooling magma deep in Mars’ crust, then was changed by water moving through it about 4.1 billion years ago.
That water is the key detail. Its chemistry shows it was altered by fluids, suggesting early Mars was warmer and wetter than today. One reviewer called it a “Rosetta Stone for Mars”, because it may help scientists read the planet’s earliest history.
Its chemistry also matches Mars’ cratered southern highlands, and the team has found 13 possible places there where it may have come from.
Why it matters
Only two other Mars meteorites are known to be this ancient, and Teghaza 001 is different from both. The others mix several rock types, while this one is a single, unmixed volcanic rock, making it the oldest known Martian lava rock of its kind.
The find does not prove that life ever existed on Mars. But it supports the idea that the young planet had the water and conditions life would have needed, when Mars may still have had surface water and a magnetic field shielding it from radiation.
What happens next
Scientists say they have only scratched the surface of what Teghaza 001 can reveal. Further study could sharpen the picture of how Mars lost its water and how its crust formed.
The 13 possible origin sites give future missions a shortlist to explore. It also strengthens the case for bringing Mars samples back to Earth, because one rock that fell here by chance cannot answer every question about the planet’s past.
This article is for general information and education only. It is not legal or financial advice.
Sources
- https://www.nasa.gov/solar-system/planets/mars/nasa-funded-study-details-one-of-oldest-mars-meteorites-ever-found/ (NASA, 29 October 2026)
- https://www.smithsonianmag.com/smart-news/this-rosy-stone-spotted-in-the-sahara-turned-out-to-be-a-4-1-billion-year-old-meteorite-from-mars-one-of-the-oldest-ever-found-180989786/ (Smithsonian Magazine, 30 October 2026)
- https://astrobiology.com/2026/10/30/university-of-new-mexico-scientists-help-uncover-4-1-billion-year-old-martian-meteorite-revealing-clues-to-planets-ancient-past/ (Astrobiology / University of New Mexico, 30 October 2026)
