A nearly 2-pound, rose-colored meteorite found in Mali in 2022 is from Mars and about 4.1 billion years old, a NASA-funded study has determined, CBS News reports. Named Teghaza 001 after the salt plain where it turned up, it is one of the three most ancient Martian meteorites found on Earth, and one of roughly 435 known to come from Mars.

Lead author Yang Liu of NASA's Jet Propulsion Laboratory said one of the paper's reviewers called it "a Rosetta Stone for Mars." Its mix of volcanic minerals, including zircon crystals, matches terrain that NASA's Mars Reconnaissance Orbiter has seen in the planet's southern highlands. Using a dating method that worked on a piece smaller than a fingernail, the team found the rock was altered by Martian water about 4.1 billion years ago, and it may have formed even earlier. The data suggest early Mars may have had a more dynamic water cycle than scientists thought.