The Kuiper Belt
 

The image below shows a schematic of our solar system viewed from above, where 50 AU is 50 times the average Earth-Sun distance.

The yellow dot indicates the position of the Sun.

The colored lines indicate the orbits of Jupiter (white), Saturn (red), Uranus (green), Neptune (Blue), Pluto (cyan), and a scattered KBO (magenta).

When the orbits of KBOs pass to close to Neptune, Neptune's gravity scatters them outward and produces a scattered KBO.

The cyan points indicate the positions of known KBOs as of January 2004.