Hidden craters reveal Earth may once have had a ring

The rings of Saturn are some of the most famous and spectacular objects in the Solar System. Earth may once have had something similar.

Unexpected ring around the dwarf planet found

The dwarf planet is known as Quaoar. The presence of a ring at a distance of almost seven and a half times the radius of Quaoar, opens up a mystery for astronomers to solve: why has this material not coalesced into a small moon?