A runner makes his way along a trail on a butte in front of the "supermoon" over Papago Park in Phoenix on May 5. This full moon is the biggest and brightest of 2012, thanks to the orbital mechanics of the moon's phases and its orbit around Earth. In this photograph, the effect is heightened dramatically through the use of a telephoto lens.
Men stand on top of a butte at Phoenix's Papago Park, hoping for a better view of the moon on May 5. Reports of the "supermoon" led to an uptick in Saturday night moongazing.
The moon is seen from San Pedro de Atacama, in Chile's Atacama Desert, on May 5. It's not unusual for the moon to be this big and close as it traces an elliptical orbit around Earth. What made this sight notable is that the moon reached perigee - its closest point to Earth - at about the same time that it reached maximum fullness.
A full moon is seen behind the minaret of the Mohamed Ali Mosque in Cairo, Egypt, during May 5's "supermoon."
A perigee moon, also known as a "supermoon," rises over the Mississippi Sound in Biloxi, Miss., on May 5. Scientists say we tend to perceive the moon as looking bigger when it's at the horizon than when it's directly overhead. This so-called "moon illusion" is related to the way our brains are programmed to interpret sky phenomena.
Fishermen cast their lines from a jetty as the moon rises over the Atlantic Ocean on May 5, near Bal Harbour, Fla.
The moon's craters and dark maria ("seas") show up clearly in a "supermoon" snapshot captured in Canton, Ohio, on May 5. A full moon appears 14 percent wider at its minimum distance than at its maximum distance, and its brightness can vary by as much as 30 percent.
The "supermoon" rises over Toronto's skyline on May 5. The Canadian city's CN Tower provided an ideal vantage point for watching the bigger-than-usual moon rise from the horizon.
The "supermoon" shines over partially blacked-out neon hotel signs on Highway 80 in Ft. Worth, Texas.
The full moon rises behind the Greek Temple of Poseidon in Cape Sounion, southeast of Athens, while tourists watch on May 5.
The full moon looms behind a mosque as birds fly in Amman, Jordan, on May 5. The next time the full moon will be as big and bright as it was on Saturday night will be on Aug. 10, 2014.