"It is theorized that earth at one time had rings, but that they later coalesced into what is now our moon." Indeed. (1997 Nature article) http://www.nature.co

"It is theorized that earth at one time had rings, but that they later coalesced into what is now our moon." Indeed. (1997 Nature article) http://www.nature.com/nature/journal/v389/n6649/full/389353a0.html http://www.nature.com/nature/journal/v389/n6649/full/389353a...