The Sun's parent cloud collapses
A nearby star dies, a cold cloud of gas is pushed over the edge, and the Solar System begins.
- When
- Known to
- ± 50 million years
- Era
- Enrichment, Stelliferous
A giant molecular cloud in one of the Milky Way's spiral arms begins to collapse, quite possibly triggered by a nearby supernova — short-lived radioactive isotopes preserved in meteorites point to one having exploded close by and shortly before. The cloud fragments, and one fragment becomes the Sun and everything orbiting it. Within roughly a hundred thousand years the collapse is well underway.