The Solar System begins
The oldest solids in existence condense out of the cooling nebula — and start the clock on everything local.
- When
- Known to
- ± 500 thousand years
- Era
- Enrichment, Stelliferous
Calcium- and aluminium-rich inclusions, millimetre-scale white specks found inside meteorites, condense directly from the hot solar nebula. Dated by uranium-lead to 4,567.3 million years with an uncertainty of only about 160,000 years, they are the oldest solids ever dated and define the age of the Solar System. Every other date in this era is measured from them.