The Kuiper belt has Pluto in it.
Kuiper belt . Originally considered a planet , Pluto 's status as part of the Kuiper belt caused it to be reclassified as a dwarf planet in 2006 . Pluto . Like other Kuiper belt objects , Pluto is primarily made of ice and rock and is relatively small -- about one-sixth the mass of the Moon and one-third its volume .