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Comet

(Sun-orbiting object with coma and possible tail)

A Comet is an object orbiting the Sun that displays a visible Atmosphere (Coma) and possibly a tail, on the side away from the Sun. They are icy, i.e., made of substances solid but that can be turned to gas at Temperatures reached in the inner part of their orbit (i.e., volatile), creating the coma and possible tail. Classically, they have long-period orbits (tens to thousands of years) that are highly elliptical so a brief portion of the orbit is visible and displays the coma and tail effects. It is thought that many comets reside at the far end of their orbits, where they move relatively slowly, which, together, are known as the Oort Cloud.

Inspection has revealed rocky surfaces. Volatiles such as water, Carbon Dioxide, Carbon Monoxide, Methane, and Ammonia make up the Ice, which may be inside.

Two well-known comets are Comet Halley (recognized in 1705 by Edmund Halley as orbiting approximately every 76 years) and Comet P/Shoemaker-Levy 9 which was observed colliding with Jupiter in 1994.


(solar system,object type)
http://en.wikipedia.org/wiki/Comet

Referenced by:
Apsis
Asteroid Belt
CAESAR
Caldwell Catalog
Centaur
Comet Planet
Catalina Sky Survey (CSS)
Deep Lens Survey (DLS)
Dwarf Planet
Eccentricity (e)
EPOXI
ESO/Uppsala Survey Of The ESO (B) Atlas
Glycine (Gly)
Kuiper Belt (K Belt)
LINEAR
LONEOS
Mass Spectrometer
Messier Catalog
Meteoroid
Minor Planet
Minor Planet Center (MPC)
Nebula
Near-Earth Object (NEO)
Occultation Observations
Oort Cloud
Coma
Origins Space Telescope (OST)
Planetesimal
Planetoid
Provisional Designation
Reflection Nebula
Rosetta
67P/Churyumov-Gerasimenko (67P)
Smith Cloud
Solar System
SPACEWATCH
SSSB
Stardust
Striae

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