Comets are visitors from the outer reaches of the solar system, and sometimes give a spectacular show to stargazers on earth. In deep space, a comet may look like an asteroid - just a lump of space rock - but as it heads towards the inner solar system and is heated by the sun, ice on the nucleus begin to sublimate and dust and gas are released to reveal a tail. Learn about the origin of the word 'comet,' famous comets in history, and more in this educational video! Like this video if you want