images

Moon Formation: ring around the earth

by

Ron Miller/Novapix

Reference

a-lun99-00017

Date

2017-01-14

4.5 billion years ago. After Theia collision and for a short time, the earth is surrounded by a ring of debris. The ring is only temporary, however: it soon begins to coalesce into a solid mass. Only a few years might have been required for it to form into a moon.