'Supermoon' Nearest Earth Tomorrow But contrary to rumor, it had nothing to do with Japan's earthquake By Matt Cantor, Newser User Posted Mar 18, 2011 8:15 AM CDT 9 comments Comments The 'supermoon' will be closest to Earth tomorrow. (Shutterstock) (Newser) – Hope for clear skies: A "supermoon" is due tomorrow. NASA scientist Jim Garvin explains that a supermoon is "when the moon is slightly closer to Earth in its orbit than on average"—a situation that’s "most noticeable" when it coincides with a full moon, as it will tomorrow. "The moon may seem bigger, although the difference in its distance from Earth is only a few percent at such times," continues Garvin. Tomorrow, the moon will be some 221,567 miles from Earth; usually it’s more like 238,000 miles, the Christian Science Monitor reports. There's been quite the buzz over this one thanks to one astrologer’s theory that the supermoon would trigger mega-storms and massive earthquakes. But there’s no connection between this and what happened last week in Japan, says Garvin. "The 'super' in supermoon is really just the appearance of being closer," and though the moon affects tides, those "tidal forces" aren't powerful enough to mess with plate tectonics.