Their origin is uncertain; why intermittent wandered suddenly appear in the region of the Sun has yet to be fully explained. The existence of comets, however, has been known for centuries; one of the earliest records dates from about 1770 B.C. Although many ancient civilizations possessed fine astronomers, before the seventeenth century there were no instruments capable of making the observations needed to compute the speed and distance of a comet, and it was not until 1682 that the successive return of the same comet was finally established. After the invention of the telescope, many more comets were discovered, their behavior examined, and their orbit calculated.