The tail of the comet is always away from the Sun because the comet rotates around the Sun.

Explanation:

The lighter mass of the comet is pushed away due to the centrifugal force alone. 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 the 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.