#billion years

The interstellar comet 3I/ATLAS carries a chemical fingerprint unlike anything in our Solar System, and it may have formed 10 to 12 billion years ago, before our Sun even existed, according to two papers published in the journal Nature.

A Sahara meteorite holds the first direct evidence of a Moon-to-Mars-sized protoplanet that orbited the young Sun before being destroyed 4.5 billion years ago.