- a celestial body moving about the sun, usually in a highly eccentric orbit, consisting of a central mass surrounded by an envelope of dust and gas that may form a tail that streams away from the sun.
Origin of comet
Examples from the Web for cometary
Was the division of the cometary mass produced by the encounter?Meteoric astronomy:
Subsequently sodium and iron lines were found in cometary spectra.Curiosities of the Sky
That numerous facts—some observed in ancient and some in modern times—have been decidedly indicative of cometary disintegration.
Before entering the solar domain, they were doubtless members of a cometary system.
At one of these epochs the cometary orbit will probably undergo considerable transformation.
- a celestial body that travels around the sun, usually in a highly elliptical orbit: thought to consist of a solid frozen nucleus part of which vaporizes on approaching the sun to form a gaseous luminous coma and a long luminous tail
Word Origin and History for cometary
c.1200, from Old French comete (12c., Modern French comète), from Latin cometa, from Greek (aster) kometes, literally "long-haired (star)," from kome "hair of the head" (cf. koman "let the hair grow long"), of unknown origin. So called from resemblance of a comet's tail to streaming hair.
- A celestial object that orbits the Sun along an elongated path. A comet that is not near the Sun consists only of a nucleus-a solid core of frozen water, frozen gases, and dust. When a comet comes close to the Sun, its nucleus heats up and releases a gaseous coma that surrounds the nucleus. A comet forms a tail when solar heat or wind forces dust or gas off its coma, with the tail always streaming away from the Sun.♦ Short-period comets have orbital periods of less than 200 years and come from the region known as the Kuiper belt. Long-period comets have periods greater than 200 years and come from the Oort cloud. See more at Kuiper belt Oort cloud. See Note at solar system.
An object that enters the inner solar system, typically in a very elongated orbit around the sun. Material is boiled off from the comet by the heat of the sun, so that a characteristic tail is formed. The path of a comet can be in the form of an ellipse or a hyperbola. If it follows a hyperbolic path, it enters the solar system once and then leaves forever. If its path is an ellipse, it stays in orbit around the sun.