Composition of a comet's tail
Name: Michelle L Harceg
What is in a comet's tail?
Comets actually have two tails: the dust tail and the gas or ion tail. The
names should tell you what is in them. Both tails always point away from
the Sun, independent of the comet's motion. The dust tail is formed of
solid particles escaping from the cometary nucleus into their own solar
orbits and may be slightly curved. It shines with reflected sunlight. The
ion tail is pushed straight back from the coma by the solar wind and solar
radiation pressure and glows from the fluorescence of the ionized molecules
CO+, N2+, OH+, CO2+, and CH+. Some comets are also surrounded by huge
(bigger than the Sun) clouds of hydrogen gas.
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Update: June 2012