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Big and Bright 'Perigee Syzygy' Moon Occurs Saturday
If you're lucky enough to have clear skies this weekend, you'll see a full moon at its closest point to Earth since January 30 of last year.

Full moon
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A full moon captured July 18, 2008. Credit: NASA/Sean Smith

The full moon of March will occur Saturday, March 19, when it will be about 221,567 miles (356,578 km) from Earth. The average distance between the Earth and the moon is about 238,000 miles (383,024 km). The furthest point away is about 254,000 miles (408,773 km).

So the moon on March 19 will be around 17,000 miles (27,359 km) closer than usual as it rounds Earth in its elliptical orbit.

The technical term is perigee-syzygy. A popularized term is "super moon."

The occurrence is more technical than visible.

A full moon at its closest point to Earth definitely will be big and bright. But it won't look much, if any, different than a "normal" full moon and will not have any readily observable effect on our planet except perhaps slightly higher tides.

The phenomena occur four to six times a year.

Michael Finneran
NASA Langley Research Center