• Question: how many planets is there?

    Asked by tmelvin to Nazim, Leila on 14 Mar 2012. This question was also asked by wall.
    • Photo: Leila Battison

      Leila Battison answered on 14 Mar 2012:

      It all really depends on what you decide counts as a planet. I think they have to be bigger than a certain size, and have a roughly circular orbit around the sun. There used to be 9 in our solar system, but Pluto was dropped from the list because it was too small. So now eight!

      But there are probably planets around lots of stars in the universe, and there are billions of stars, so there could be billions of planets out there

    • Photo: Nazim Bharmal

      Nazim Bharmal answered on 19 Mar 2012:

      If you counted the planets in our solar system, there are 8 plus “Plutons” which are nearly planets, like Pluto and a few others (3 of those I think). If you counted all the planets around other stars, we don’t know, but somebody recently estimated at least 1/3 of stars have planets in our galaxy. I think there are around one billion stars in the galaxy so at least 300 million planets!

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