the protoplanet's collision with the earth forms the moon. (during the Hadean, when earth was nothing but a hot ball of stone, life didn't excist yet). - the first prokaryote life forms due to meteorite rains. Inside of these meteorites are the elements needed to create this life (Archean). - Eukaryotes, a more complex form of life, emerges during the Proterozoic due to the excistens of oxygen in the sky, which is created by bacterias whom are prokaryotic.
