Sahara Meteorite Reveals an Ancient Piece of Mars

The rose-colored rock, named Teghaza 001 after a nearby salt plain, is a nearly two-pound piece of Mars. Researchers identified its Martian origin by comparing its chemistry and minerals with observations and samples from NASA missions. Its age makes it one of only three known ancient Martian meteorites on Earth.

Scientists used a precise dating technique on a mineral sample smaller than a fingernail. The analysis found that water altered the rock about 4.1 billion years ago, though the rock itself may have formed earlier. Its volcanic minerals include zircon crystals, which resemble material observed in Mars’ southern highlands.

The findings offer evidence about how Mars’ crust developed as magma cooled, and how water later changed the surface. They also suggest the young planet may have had a more active water cycle than previously thought. One researcher said the meteorite could preserve signs of interactions between water and rock, and perhaps of the Martian atmosphere as the planet lost water.

Teghaza 001 is a single, intact igneous rock, unlike the fragment-rich Martian meteorite known as Black Beauty. Researchers say old Martian rocks are scarce in collections, in part because an impact must eject them from the planet and the rocks must survive the journey. Further study of Teghaza 001 is expected.