Far out in the solar system we find hundreds of icy objects which were first posited by Gerard Kuiper  in the 1950’s.  This region is now known as the Kuiper Belt.  Here is a rare picture of the Kuiper belt The first of these objects discovered is, of course, PlutoFor nearly twenty years now, more and more of these objects have been identified, with orbits similar to Pluto’s.  These newly discovered bodies are the reason that Pluto’s status as a planet first came into question. These newly discovered objects now number in the hundreds.
Carpe Caelum Planetary Astronomy