Question

what happens to the tail of a comet when it moves far away from the Sun

Answer 1

IF A COMET MOVES AWAY FROM SUN TAIL OF COMET DISSAPPEAR

Answer 2

The gas (water vapor, carbon monoxide, carbon dioxide, and traces of other substances) and dust forms an “atmosphere” around the nucleus called a "coma." Material from the coma gets swept into the tail. Ascomets move close to the Sun, they develop tails of dust and ionized gas.