A supernova that exploded close to our newly forming sun could have destroyed what became our solar system — if it weren't for a shield of molecular gas.
Scientists reached this conclusion by studying isotopes of elements discovered in meteorites. These space rocks are pieces of asteroids, which formed from material that was around when the sun and then the planets of the solar system formed. As such, meteorites are fossils of a sort, allowing scientists to reconstruct the evolution of the solar system.
