Ancient Martian meteorite offers a new record of early water and crust

A meteorite discovered in the Sahara in 2022 is giving researchers an unusually old record of the Martian crust. In findings described by NASA on October 29, scientists dated minerals in the roughly 800-gram rock, known as Teghaza 001 after the region of Mali where it was found. The evidence points to alteration by water about 4.1 billion years ago, suggesting that the original rock formed even earlier. The study was published in the journal Science, and related research on its water content appeared in Science Advances in June.

Teghaza 001 contains a varied group of igneous minerals formed as molten rock cooled and later changed through contact with water. Researchers used microscopic zircon crystals and a precise rubidium-strontium dating technique to reconstruct parts of that history while preserving most of the rare specimen. Its composition resembles materials observed in the heavily cratered southern highlands of Mars. The team identified 13 possible locations that share relevant mineral and chemical characteristics; none has been established as the actual point of origin.

The meteorite is among the oldest known pieces of Mars discovered on Earth. Scientists compare its chemical fingerprints with measurements from spacecraft and rovers to establish its planetary origin. Researchers say the stone could illuminate interactions among volcanic rocks, underground water and perhaps the planet’s changing atmosphere. The findings do not demonstrate that life existed on ancient Mars. Instead, they provide a rare physical sample for testing how the planet’s surface and water systems evolved during its earliest history.