NASA-Funded Study Reveals One of Oldest Mars Meteorites Ever Found in Sahara Desert

A meteorite discovered in the Sahara Desert in 2022 has been identified as one of the oldest known pieces of Mars, according to a NASA-funded study. Scientists determined that the nearly 2-pound rock, named Northwest Africa 15200, formed more than 4.1 billion years ago, during a period when Mars was still in its infancy. The findings provide a rare glimpse into the Red Planet's earliest crust and its geological evolution. The meteorite, a type known as a shergottite, was analyzed using advanced dating techniques that measured the decay of radioactive isotopes in its minerals. The results suggest that the rock crystallized from magma on Mars about 4.1 billion years ago, making it older than most other Martian meteorites found on Earth. This ancient age places it close to the time when Mars and Earth were both forming their first stable crusts. Why it matters: Studying such ancient Martian rocks helps scientists understand the early history of Mars, including its volcanic activity and the potential for habitability. Because the meteorite was ejected from Mars by an impact and later landed on Earth, it serves as a free sample-return mission, offering clues about the planet's composition without the need for a costly space mission. The study, led by researchers at institutions including the University of Glasgow and Curtin University, was published in the journal Nature Communications. As NASA and other space agencies prepare for future Mars sample-return missions, meteorites like Northwest Africa 15200 remain invaluable for piecing together the planet's deep past. This ancient rock may hold secrets about when Mars lost its magnetic field and much of its atmosphere, transforming from a warmer, wetter world into the cold desert we see today.