Sahara meteorite may hold clues to lost planet from early solar system

A meteorite discovered in the Sahara Desert, designated NWA 12774, is providing scientists with a rare glimpse into the early solar system. Estimated to be 4.56 billion years old, this exceptionally rare angrita meteorite, with fewer than 70 known specimens globally, is believed to be a fragment of a protoplanet, a celestial body that did not coalesce into a full planet.

Research published in Earth and Planetary Science Letters by scientists at the University of Colorado Boulder suggests NWA 12774 originated from a massive protoplanet. The key evidence lies in the meteorite's clinopyroxene crystals, which contain unusually high levels of aluminum. This indicates the crystals formed under significant pressure, a finding confirmed by a specialized geobarometer tool developed by the researchers.

The analysis revealed the angrita formed at pressures of at least 17.5 kilobars, over 15 times the pressure at the deepest point of Earth's ocean. This suggests the meteorite came from a body with a radius between approximately 1,000 and 3,300 kilometers, potentially approaching the size of Mars. While this offers compelling evidence, researchers acknowledge that the findings do not yet conclusively prove the existence of such a protoplanet.