Why is the distance between Earth and Moon increasing? Just like a spinning ice skater whose rotation slows as he extends his arms, the Earth-Moon distance is lengthening because Earth is spinning slower each day. The Moon's gravitational influence is slowing Earth's rate of rotation down by one and a half thousandths of a second every 100 years. The loss of rotational energy -- angular momentum, for the physicists in the crowd -- is necessarily matched by an increase in the Moon's angular momentum, which results in a larger orbit for the Moon.
Currently, the Moon moves less than two inches a year farther away from Earth -- a tiny amount, but easily measurable with modern laser-ranging devices. »FAQs about StarDate Online
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