Unit 11 · Earth and UniverseComets
Words from This Lesson
- Comet: a heavenly body that revolves round the Sun showing a long bright tail.
- Nucleus: the frozen solid centre of a comet.
- Coma: the cloud like shell of vapour and gas around the nucleus.
- Tail: the long bright stream of coma material blown out by the solar wind.
- Dust tail: the thick white tail made of dust grains.
- Ion tail: the bright, thin, bluish tail made of ionised gas.
- Solar wind: the flow from the Sun that blows the material of the coma outward.
- Endocomet: a comet that revolves within the solar system.
- Exocomet: a comet arriving from outside the solar system.
- Extinct comet: a comet that has lost its ice and gas and has turned into an asteroid.