-
3
3.8 bya
Oort cloud reaches maximum mass. -
4
4.6 bya
Pre-solar nebula forms and begins to collapse. Sun begins to form. -
4
4.5 bya
Terrestrial planets and the Moon form.
Giant impacts occur.
Water delivered to Earth.
Sun becomes a main-sequence star. -
4
4 bya
Resonance in Jupiter and Saturn's orbits moves Neptune out into the Kuiper belt. Late Heavy Bombardment occurs in the inner Solar System. -
5
5 bya
Previous generations of stars live and die, injecting heavy elements into the interstellar medium out of which the Solar System formed.