More than 4.5 billion years ago, a huge world, potentially as large as the moon or even Mars, traveled around the young Sun before a violent collision shattered it into pieces.
Scientists now say they have found the first direct evidence that this long-lost planetary embryo, known as a protoplanet, once existed. The discovery, described in the journal Earth and Planetary Science Letters, points to a type of planetary evolution unlike anything previously recognized.
"It's incredible to think there was once a world this large," said Aaron Bell, an assistant research professor in the Department of Earth Science at the University of Colorado Boulder. "We only know it existed because a few fragments of it happened to land on Earth. These meteorites preserved evidence of a completely different pathway through which early planets developed."
Rare Meteorite Holds Clues to a Lost World
The breakthrough came from a meteorite discovered in the Sahara Desert called Northwest Africa (NWA) 12774, an angrite meteorite.
