Lost Moon-Sized Protoplanet Discovered

Scientists have discovered definitive evidence of a lost, moon-sized protoplanet that existed in the early solar system, approximately 4.5 billion years ago. This evidence comes from a rare meteorite, NWA 12774, found in the Sahara in 2019. Analysis by Aaron Bell and his team at the University of Colorado Boulder revealed aluminum-rich clinopyroxene crystals within NWA 12774, indicating formation under immense pressure (over 17.5 kilobars), far exceeding what a small asteroid could generate. This suggests the parent body was much larger, potentially over 1,800 kilometers in radius, comparable to the Moon and approaching the size of Mars. The unique chemistry of NWA 12774, with low silica levels, challenges previous assumptions that angrites originated from small asteroids. This discovery points to a distinct planetary evolution pathway different from Earth and Mars, suggesting multiple types of planetary bodies emerged in the solar system's infancy. The lost world was likely destroyed in violent collisions during the early, chaotic formation of the solar system, with fragments like NWA 12774 eventually landing on Earth.