Ancient Martian Meteorite Teghaza 001 Discovered in Sahara Provides New Clues About Early Mars Water

A reddish rock fragment recovered from the Sahara desert has been confirmed as a 4.1 billion-year-old piece of Mars, the researchers reported in the journal Science. The meteorite, designated Teghaza 001 after a nearby abandoned salt-mining settlement in Mali, is among the oldest Martian rocks found on Earth.

Lead author Yang Liu, a planetary scientist at NASA’s Jet Propulsion Laboratory, said the find is “very rare” because of its age. The rock’s mineral assemblage, including igneous minerals and zircons, offers a snapshot of Mars a few hundred million years after the planet formed, providing new information on the early Martian mantle and crust.

“It’s very unusual, and I see a lot of them in the sample,” Liu said, referring to the unexpected abundance of zircons, which prompted further analysis.

The team used uranium-isotope dating and two additional methods to confirm the age. Subsequent analysis of apatite minerals in the sample showed water was present when the rock formed, but also indicated that much of Mars’s water had already been lost to space, as evidenced by a high deuterium-to-hydrogen ratio.

“The water in the apatite appears to have come from two different sources,” explained Lee Saper, a planetary scientist at NASA Ames Research Center. “Some of the water was in the magma that rose from the Martian mantle… other water molecules came from the surface and the atmosphere.”

Comparisons with data from Mars orbiters allowed the researchers to propose 13 possible source locations on the planet. The scientists plan further studies, noting that only a small portion of the meteorite has been examined so far.

“We looked at a small part of it,” Saper added. “There’s a much more complex story that’s yet to be uncovered.”