Scavenger Hunt II Answer Key Comets are unpredictable. Their composition seems to represent the original makeup of the vast nebula that ultimately condensed to form the sun and planets. Many astronomers believe early collisions between Earth and comets brought the vast amounts of water that make up Earth's oceans. It's thrilling to watch a comet and know it may have last traveled through Earth's skies hundreds, thousands, or even millions of years ago. A comet's 3 main parts are the nucleus, the coma, and the tail.
Most meteors come from comets.
Meteors become visible as a result of friction caused by air molecules slamming against the surface of the high-velocity particle. The friction typically causes meteors to glow blue or white. A meteor shower occurs when Earth's orbit intersects the orbit of a meteor stream. A meteor storm occurs when Earth encounters closely grouped meteors within a meteor stream. The Leonids' parent comet is Tempel-Tuttle.