Comets: icy visitors with changing tails
Comets contain ice, dust, and rocky material. As a comet approaches the Sun, warming releases gas and dust around its nucleus.
Tails can develop and stretch away from the Sun. A comet does not need to rush through air to make a tail.
Wonder about this
Does a comet’s tail always point behind its direction of travel?
A science clue
No. Tails are shaped by sunlight and solar wind, generally away from the Sun.