The left panel shows Comet Hartley 2’s orbit. The central panel shows a larger portion of the Solar System, including the Kuiper Belt. The Kuiper Belt is one of the two main reservoirs of comets in the Solar System. Comets like Hartley 2 are believed to have formed here and to have migrated inwards. The right panel shows the Oort Cloud, the other main reservoir of comets located well beyond the outer Solar System.