• Question: Does the moon move away from the earth or nearer?

    Asked by Hello to Steve on 7 Mar 2016.
    • Photo: Steve Marsden

      Steve Marsden answered on 7 Mar 2016:

      Hi Hello. It is moving away from us, by just under 4 cm per year.

      The moon moves around us once per month while we rotate beneath it each day. The sea is drawn towards the moon, resulting in tides. These tides cause the Earth’s rotation to slow down (days get about 1.7 milliseconds longer per century). This energy lost from the Earth’s rotation is transferred to the moon, speeding it up, and pushing it into a higher orbit.

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