The late veneer
A final rain of asteroids delivers the gold, platinum and possibly much of the water at Earth's surface.
- When
- Known to
- ± 50 million years
- Era
- Hadean
Iron-loving elements such as gold, platinum and iridium should have sunk into the core with the iron, yet they are far more abundant in the mantle than that allows. The explanation is a late addition of perhaps 0.5% of Earth's mass, arriving after the core had finished forming. The same delivery may account for a substantial share of Earth's water — every gold atom in every ring was added to the planet after it was otherwise complete.