Comet

n. [Fr. comète, Lat. cometes, cometa, Gr. κομήτης, long-haired (sc. ἀστήρ, star), a hairy star, comet, from κομᾶν, to wear long hair, from κόμη, hair, Lat. coma.] (Astron.) One of those members of the solar system which usually move in very eccentric orbits, approaching very near to the sun in their perihelion, and receding to a very great distance from it at their aphelion. A comet commonly consists of three parts: the nucleus, the envelope, or coma, and the tail; but one or more of these parts is frequently wanting.

So from the dread immensity of space Returning, with accelerated course, The rushing comet to the sun descends. Thomson.