- 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 comet
They found that there are roughly 1,900 hydrogen atoms for each deuterium atom in the water on Comet 67P.Are Comets the Origin of Earth’s Oceans?
Matthew R. Francis
December 14, 2014
The probe appears to be sitting at the bottom of a "cliff" on the comet, but beyond that it's hard to tell.
The basic approach went as planned: after separating from the Rosetta orbiter, Philae coasted slowly to the comet surface.
Landing on any other world is hard, but Comet 67P is especially challenging, even apart from the low gravity.
The comet is basically shaped like a rubber ducky, but with a much rougher surface.
What a comet is to the earth, was that sad woman to the town.The White Old Maid (From "Twice Told Tales")
The Emperor pointed it at the comet and the comet was quenched.The Chinese Fairy Book
Look up Dan and 'Chuck' and the rest of the crowd again, at Comet's place.Salvage in Space
John Stewart Williamson
We are like a comet, bright at the head but tailing away into mere gas behind.The Stark Munro Letters
J. Stark Munro
And off he went like a comet, with the fashionable woman for his tail.The Christian
- 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 comet
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.