Comets Hello, my name is Seth Hillman, and I researched the comet, meteor, asteroid section in our website. The definition of a comet is a small gaseous body in planetary space consisting of a head and a tail. The name, from the Latin word coma, or hair, comes from its appearance.
Comets obey the laws of gravity, as do the planets.
All, or almost all, comets are part of the solar system. The motion of a comet, however, is different from that of the planets. The planets move in the same direction, in almost the same plane, and in nearly circular orbits around the sun. Comets travel in highly eccentric orbits in both directions, and their orbital planes can be inclined at any angle. At a great distance from the sun, comets usually have no tail, but they may have a faintly visible head.