These objects may be leftover debris from our solar system's early formation. But Pluto is spherical and it does orbit the Sun. Although this controversy has come up on occasion, Pluto is still classified as a planet. Pluto's moon Charon was first found in 1978. Pluto is made from a mixture of rocky and icy material, and it appears to have seasonal changes, but we don't know much else about it.
Detailed study requires a close-up look.
A mission called Pluto-Kuiper Express , managed by JPL, would fly past Pluto and its moon Charon, and study Kuiper Disk objects. The mission would launch in 2004, and would take about ten years to reach its destination.