Comets: icy visitors with changing tails
Solar heating causes volatile ices to sublimate into gas, helping lift dust from the nucleus. Sunlight and the solar wind affect the escaping material and shape different tails.
A comet’s tail is not simply a trail pointing backward along its orbit. Its direction depends strongly on the Sun, so a comet moving away from the Sun can travel with tails extending ahead of it.
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.