Asteroids & Comets
Comet
A icy visitor from the outer Solar System
About Comet
A comet is an icy small body that when passing close to the Sun heats up and releases gases, producing a visible atmosphere (coma) and sometimes a tail.
Scientific Facts
Comets have a nucleus of ice and dust. Their tails always point away from the Sun due to solar wind. The Oort Cloud contains billions of comets.
Interesting Facts
Halley's Comet returns every 75-76 years. Comet tails can be millions of kilometers long. The word comet comes from the Greek "kometes" meaning "long-haired."
Fun Facts
Comets are "dirty snowballs." The impact of a comet may have brought water to Earth. There are over 3,700 known comets.
Discovery
Known since ancient times. Halley's Comet first recognized as periodic by Edmond Halley in 1705.