Scientists have determined that a meteorite known as Tagaaza 001, recovered in the Sahara, is approximately 4.1 billion years old and contains evidence that liquid water existed on early Mars.
The red-coloured rock is the oldest of the 435 Martian meteorites identified so far. Analysis by researchers at NASA’s Jet Propulsion Laboratory shows chemical interactions with water occurred as the rock cooled in the planet’s crust.
The meteorite is a gabbro-type rock formed from magma deep within Mars. It contains feldspar, pyroxene, and uranium-bearing zircon crystals. The findings, published in the journal Science, provide a rare sample of the planet’s early history.
Mars is now a cold, dry world, but geological evidence indicates it once had rivers, lakes, and possibly oceans. The meteorite was found about 21 miles from a Malian city and had broken into eight pieces.
Lead researcher Yang Liu said the rock offers a window into a period when Mars was warmer and wetter, potentially more hospitable to microbial life. The solar system’s planets formed roughly 4.5 billion years ago.