• Question: why is the moon not a planet?

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      Asked by stasssssss to katy, Lauren, Richard, Stuart on 16 Mar 2016.
      • Photo: Stuart Atkinson

        Stuart Atkinson answered on 16 Mar 2016:

        The Moon is classed as a satellite – that is, a body that orbits around a planet. Other planets in the solar system have moons, such as Mars, which has Deimos and Phobos. Jupiter has loads, including the largest, Io, Europa, Ganymede and Callisto, which were known to Galileo and can be seen through a small telescope. Saturn has the mysterious Titan which is swathed in a deep atmosphere of organic smog.

        A planet is a body that orbits the Sun and must be of a certain size, which is why poor Pluto is no longer classed as a planet, but a ‘dwarf planet’.

        The funny thing is, if the Moon were orbiting the Sun like any other planet, in its own orbit, it would be called a planet as it is big enough to fit the criteria! It is larger than Pluto.

      • Photo: Lauren Laing

        Lauren Laing answered on 16 Mar 2016:

        Hiya, great question.
        Stuart is right, the Moon is simply classed as a satellite! Both the Moon and Pluto are not classified as planets because they are not large enough.

      • Photo: Richard Friend

        Richard Friend answered on 16 Mar 2016:

        The word planet comes from Greek words which mean wandering star, as the first planets looked like stars which moved against the background of stationary stars. But for something to be classed as a planet it needs to orbit a star, and the moon orbits the Earth.