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[[Image:Comet wild 2.jpg|right|thumb|Photograph of the comet code named ''Wild 2'']]

[[Image:Comet wild 2.jpg|right|thumb|Photograph of the comet code named ''Wild 2''|250px]]

A comet is a ball of ice consisting of frozen gases as well as water, typically having a diameter of less than five kilometers. A comet develops a tail made of ice, gas and dust when it is close enough to the sun for some of the ice to melt. Comet tails can be millions of kilometers in length.

A comet is a ball of ice consisting of frozen gases as well as water, typically having a diameter of less than five kilometers. A comet develops a tail made of ice, gas and dust when it is close enough to the sun for some of the ice to melt. Comet tails can be millions of kilometers in length.

Comets in orbit around stars may be highly eplitical rather than circular ( such as planets ) which takes them past the orbit of pluto.  Some mass of the comet will sublimate with each pass by the sun and after many passes the comet may no longer be active and be simply an asteroid.

Comets in orbit around stars may be highly eplitical rather than circular ( such as planets ) which takes them past the orbit of pluto.  Some mass of the comet will sublimate with each pass by the sun and after many passes the comet may no longer be active and be simply an asteroid.

[[category:astronomy]]

[[category:astronomy]]