Why does a comets tail point away from the sun?

The tail of a comet is made up of gas and tiny particles that are carried away from the sun by the solar wind. Comets are formed mostly from ice and dust, and their tails only form when they are close enough to be melted by heat from the sun.

As the nucleus of a comet begins to melt, it forms a cloud of gas and small particles known as the coma. When comets travel close enough into the center of our solar system, pressure from sunlight causes the coma to form a tail that stretches away from the sun.