Where do comets come from?
Comets originate in two distinct areas of the photo voltaic system. Comets from the Kuiper Belt past Neptune are called short-period, since it takes them less time than other comets to go round the Sun. Comets from the Oort Cloud take as lengthy as 30 million years to complete one orbit and are therefore called long-period comets. There are about a trillion comets in the Oort Cloud. The Oort Cloud itself is at the edge of the photo voltaic system, almost a quarter of the way from the Sun to the subsequent star, Proxima Centauri.
