The Origins of Comets

The majority of all the short period comets have been captured by Jupiter. The most interesting feature of a comet is its characteristic tail, which develops and increases in size and brilliance as the comet approaches the Sun. As the tail is always turned away from the Sun, it follows the comet as it draws near the Sun and precedes it as it departs. Long straight tails consist chiefly of hydrogen, curved tails of hydrocarbons, and short bushy tails of mixtures of iron, sodium, and other metallic vapors. At times the same comet will have two or more tails of different types.