Comets are pieces of ice and rock left over from the formation of stars and planets. In our solar system, they usually drift through space in the Oort Cloud, an area beyond our solar system filled with debris.

A comet has two main parts to it: a head and a tail. As a comet approaches the inner solar system, the Sun begins to vaporize the ice and rock. The result of this vaporization is a tail of ionized gas that appears as a streak behind the comet. There is also plasma and an envelope of hydrogen separate from the tail, but they are not visible on Earth. Only spacecraft have been able to detect these formations.

Go Here The most famous and scientifically interesting incident with a comet was the collision of Shoemaker-Levy 9 with Jupiter in 1994. In an earlier pass close to Jupiter, the comet was broken up into several pieces. When it came around again, it was set to collide with Jupiter. During the course of a week, the fragments struck Jupiter near its southern pole on the far side from Earth. The collisions disturbed the gas giant, causing gas bubbles and scarring in the surface that looked like scorch marks. From this unique opportunity, astronomers were able to see firsthand the effects of a comet's impact and may able to explain how such an impact would affect Earth.

Comets do not come around as often as they should. You should make the most of every opportunity to go outside and see a comet for yourself. They are a sight to behold!

For more information on comets, consult the following links:

  • Windows to the Universe has a good description of comets as well as an interactive comet animation.
  • Solarviews has a small site on the Shoemaker-Levy 9 impact with Jupiter, including several photos of Jupiter with impact marks.
  • NASA'S Jet Propulsion Laboratory clash of clans hack has comet observations, including details on upcoming comet sightings.