Question

Why does comet have a long and bright tail

Answer 1

The streams of dust and gas thus released form a huge, extremely tenuous atmosphere around the comet called the coma, and the force exerted on the coma by the Sun's radiation pressure and solar wind cause an enormous tail to form, which points away from the Sun.

Answer 2

Answer:

The streams of dust and gas which is released from a huge, extremely tenuous atmosphere around the comet called the coma , by the sun's radiation pressure and solar wind cause an enormous tail to form which always points to the Sun.