This is a drawing which shows where the Kuiper Belt may be located.
Click on image for full size
Beyond the orbit of Pluto is a region which contains objects which look like planetismals. The objects are very small, and not very bright. It takes hundreds of years for these objects to go around the sun. Because they move so slowly,finding them is difficult. Where these objects came from and how they got there is still a mystery, but they probaby condensed with the planets as part of the original solar nebula. The region is called the Kuiper Belt, after Gerard Kuiper who first thought of it. The first object in the Kuiper Belt was discovered in 1992.
This picture shows the region of space where the Kuiper Belt is. In this picture, the observer is looking down on the solar system from above. The picture shows a region from the sun to 120 AU. The earth is so close to the center of the drawing that it does not show up.
This region is sometimes called "trans-Neptunian space" because even the planet Pluto could really be part of the Kuiper Belt.
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