When a comet is on a far distance from the sun it is no more than a dirty snowball of frozen gas and dust. When it approaches the sun it warms up. That means that the gas and dust form a fuzzy comet, the tail can be ten times the diameter of the Earth. Comet tails are so tenuous that the stars can be seen shining undimmed through them. Some of the comets seem to have an anti tail pointing towards the sun, this is a perspective effect.
Comets appear fuzzy and nebulous, the comets are far off the sun and return to distant regions.
The comet near by the sun is a comet that is blasted by the solar radiation . Most of the astronomers know that the comet tails generally point away from the sun. The astronomers now believe that a great thin cloud of comets surround the outermost planets reaching out more than a billion miles almost half away to the nearest stars, they are named the Van Oort clouds named after a Dutch scientist and astronomer.