Question

why does the tail of comet always point away from sun

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

The tail of comet always point away from the sun because of following reason:

Explanation:

• Because of the radiation pressure of sunlight, comet tails will always point away from the sun.
• The force of sunlight on microscopic dust particles, which pushes them away from the sun, is larger than the gravitational force acting in the opposite direction.
• As a result, a comet's tail trails behind the nucleus during its incoming trip, but trails in front of the nucleus during its outbound passage back to the outer solar system.