A rose-coloured rock from a Malian salt plain is Mars, 4.1 billion years ago — back when it had rivers

It weighs about 800 grams, it is rose-coloured, and it sat on the Teghaza salt plain in Mali until 2022. The meteorite Teghaza 001 has now been dated by NASA JPL scientist Yang Liu, using tiny zircon crystals, to at least 4.1 billion years — the oldest known single-type Martian lava rock, recognised by University of New Mexico scientist Carl Agee. Its manganese-rich patches and oxygen chemistry show it was altered by flowing fluids: evidence that early Mars was wetter and more Earth-like than the cold desert we photograph today. Published in Science, the rock is a time capsule from a Mars that had water moving through stone.