Rare meteorite provides evidence of giant early planet

Four-and-a-half billion years ago, a massive world—possibly as big as the moon or even Mars—orbited our sun before crashing into another celestial body and shattering into rubble. Now, in a paper published in the journal Earth and Planetary Science Letters, scientists report the first definitive evidence that this lost planetary embryo (protoplanet) existed. Its unique geological makeup challenges long-held assumptions about how planets evolve.