The Solar System
A great thing
In Roman mythology Neptune (Greek: Poseidon) was the god of the Sea. Neptune is the eighth planet from the Sun and the fourth largest. Neptune's blue color is largely the result of absorption of red light by methane in the atmosphere but there is some additional as-yet-unidentified chromophore which gives the clouds their rich blue tint.
A comet is an icy small Solar Systen body that, when close enough to the Sun, displays a visible sometimes called a tail. Both the coma and tail are illuminated by the Sun and may become visible from Earth when a comet passes through the inner Solar System. The streams of dust and gas each form their own distinct tail, pointing in slightly different directions.
They are very dense; a white dwarf mass is comparable to that of the Sun, and its volume is comparable to that of the Earth. The nearest known white dwarf is Sirius B, 8.6 light years away. White dwarfs are thought to be the final evolutionary state of all stars whose mass is not high enough to become a neutron star.