• Question: how many dwarf planets are in a solar system

    Asked by Simmins to Aisling, Colin, Laurence, Ned, Niamh on 7 Mar 2016.
    • Photo: Laurence O'Rourke

      Laurence O'Rourke answered on 7 Mar 2016:

      Wow, great question. The two well known ones are Pluto and Ceres but there are many more existing outside the orbit of Neptune – these are called Trans-Neptunion objects (TNOs) and indeed there are also some dwarf planets located there. I’d say less than a hundred would exist in total but this is really based on guesswork as there’s a lot of objects which are really big that are far from the sun which have yet to be discovered.

    • Photo: Colin Shirran

      Colin Shirran answered on 10 Mar 2016:

      There are two that we (or maybe just I) know of, Ceres (which exists between Mars and Jupiter and Pluto. I would say that there are definitely far more in the solar system out past Neptune that we haven’t discovered yet.