Chondrules and the first planetesimals
Molten droplets flash-heated in the disk clump into the first bodies large enough to hold themselves together.
- When
- Known to
- ± 2 million years
- Era
- Hadean
Millimetre-sized beads of once-molten rock form in the disk in brief heating events still not fully explained, and accrete with dust into planetesimals kilometres across. Once a body is large enough its own gravity dominates, and growth accelerates. Meteorites falling to Earth today are mostly fragments of these first-generation bodies, which is why they can be dated so precisely.