What are comets made of?

The answer

Comets are composed of ice (water, carbon dioxide, methane, ammonia), rock, dust, and organic compounds - often described as 'dirty snowballs' or 'icy dirt balls.' When a comet approaches the Sun, its ices sublimate (turn directly from solid to gas), creating a glowing coma and spectacular tails. The gas tail (blue, pointing directly away from the Sun) is pushed by solar wind, while the dust tail (white, curved) follows the comet's orbital path. The Rosetta mission's 2014 visit to Comet 67P revealed complex organic molecules and an unexpectedly rugged, duck-shaped body.