Question

What makes the comet visible?

Answer 1

As answered previously...

Comets are celestial bodies which orbit around the sun. They are not planets or dwarf planets. A comet has a nucleus and sometimes a tail. The nucleus may be a collection of dust, ice or rocky substances. When a comet enters the inner solar system, the solar radiation causes the volatile materials within the comet to vaporize and stream out from the nucleus. This stream is called “coma”. When the coma is exerted forces from Sun’s radiation and solar wind, the tail of the comet is formed. The tail of the comet is pointed away from the sun.