Kuiper Belt Objects

Comets @ Planet X - Xena Pluto @

Kuiper Belt

Often called our Solar System's "final frontier," the Kuiper (pronounced Ki-Per) Belt is disk-shaped region of icy debris is about 12 to 15 billion kilometers (7.5 billion to 9.3 billion miles) from our Sun. Although astronomer Gerard Kuiper proposed its existence in 1951, it wasn't until 1992 that astronomers detected a reddish speck about 42 AU from the Sun -- the first time a Kuiper Belt object (or KBO for short) had been sighted.