cometary outgassing

Cometary outgassing occurs when a comet approaches the Sun, causing its surface— primarily made of ice, dust, and other materials—to heat up. The heat causes the ices to vaporize, turning into gas that escapes the surface and forms a glowing envelope around the comet called a coma. This process also produces jets of gas and dust that stream away from the comet, creating its characteristic tail. Outgassing is driven by the sublimation of ices and reveals the comet's composition and activity as it interacts with solar radiation.