Why do comets have tails?
Comet's Cosmic Hair
Why do comets have tails?
Picture a dirty snowball the size of a mountain, hurtling through the darkness of space. For most of its life, a comet is just... there. Silent. Frozen. Ordinary. But then something changes.
The comet begins falling toward the Sun. As it gets closer, the Sun's heat wakes it up. The ice on the comet's surface — water ice, but also frozen gases like carbon dioxide and methane — starts to warm. And when ice in space warms up, it doesn't melt. It does something more dramatic: it jumps straight from solid to gas, skipping liquid entirely.
