~	Comets have been known since ancient times. There are Chinese records of Comet Halley going back to at least 240 BC.
~	Comets are made up of dust and ice. For this reason, comets are sometimes called "dirty snowballs" or "icy mudballs".
~	Most comets have orbits which take them far beyond the orbit of Pluto. These types of comets are seen once and then disappear for a thousand years!
~	By far the most famous comet is Comet Halley but Shoemaker-Levy 9 gained lots of attention for a week in the summer of 1994.
~	As of 1995, scientists have catalogued 878 comets.