You can learn a thing or two
Parts of a comet
Nucleus: Frozen center of head and it is small.
Coma: Rough blob of gas surrounds nucleus. The coma is made out of water vapor, carbon dioxide gas, ammonia, dust, and neutral gases.
Iron tail: melted iron (liquid/gas).
Dust tail: Fades away, also it is made out of dust.
Hydrogen envelope: Hydrogen gas surrounds the coma of the comet and trails along for millions of miles.