Grab your telescopes and cameras and look to the heavens Saturday night May 5. That’s when we’re in for a "supermoon," the biggest, brightest moon of the year.
“The last full moon so big and close to Earth occurred in March of 1993,” Geoff Chester of the U.S. Naval Observatory in Washington D.C. told USA Today.
This supermoon (a phrase coined by astrologer Richard Nolle in 1979) will appear especially large because the moment of perigee—when the moon is closest to the Earth in its monthly rotation—will coincide with the appearance of a perfectly full moon, Smithsonian points out. During last year’s supermoon on March 19, 2011, for comparison, the perigee and full moon were 50 minutes apart.
On Saturday at 8:34 p.m. PT, the moon reaches full moon status—when the earth, moon and sun are all in alignment. One minute later, at 8:35 p.m., “perigee” will occur.
The best time to photograph a full moon though, experts say, is at “moonrise.” Moonrise on Saturday will take place at 4:55 p.m. When the moon is near the horizon, illusion mixes with reality to produce a truly stunning view, NASA reports. Low-hanging moons look unnaturally large when they beam through trees, buildings and other foreground objects.
The moon will be 221,802 miles away from Earth Saturday night; (the average distance is 238,855 according to NASA.) That’s 17,053 miles closer.
This all translates to a moon that will appear 14 percent larger and 30 percent brighter than other full moons this year, according to NASA. (An astronomer interviewed by National Geographic says 16 percent bigger.)
For anyone living close to water—a perigee full Moon brings with it extra-high “perigean tides,” but this is nothing to worry about, according to NOAA. Lunar gravity at perigee pulls tide waters only a few centimeters (an inch or so) higher than usual. Local geography can amplify the effect to about 6 inches.
- 'Supermoon' Photos from Around the World: March 19, 2011
- Supermoon Returns in May 2012 | Video
- How the 'Supermoon' Looks (Infographic)