Notes – Other Objects in the Solar System (“Space Debris”)
What Are Comets?
When they near the sun, comets have distinct parts:
 Chunks of ice and dust that orbit the sun.
 Also known as “dirty snowballs.”
 Nucleus – solid center
 Coma dust and gas that surrounds the nucleus
 Tail – dust and gas pushed out into space by the
Solar Wind
**The tail always faces away from the sun
Tail
Nucleus
Coma
Where Do Comets Come From?
 The Oort Cloud a giant sphere surrounding the solar system. (long period comets)
 The Kuiper Belt a band located past the orbit of Neptune. (short period comets)
 Comets are pulled out of the Oort Cloud or Kuiper Belt by gravity.
How Does A Comet End?
 As it orbits the sun, it leaves behind pieces of rock called meteoroids.
 When the Earth passes through an area of meteoroids, it causes a meteor shower.
 The comet will eventually vaporize after too many trips around the sun.
The Kuiper Belt & Trans-Neptunian Objects
 A region beyond Neptune where not only comets but also at least 1,000 pluto-like objects
orbit the sun though over 100,000 are thought to exist.
 Called Kuiper Belt Objects or KBO’s. The largest are known as “dwarf planets.”
 Any that has an orbit past Neptune (including KBO’s and those that lie beyond in the
scattered disk and the Oort Cloud) is referred to as a TNO or Trans Neptunian Object.