Rare ‘Supermoon’ appears

March 20, 2011 at 12:00a.m.

McClatchy Newspapers

LOS ANGELES

As the sun set in the west on Saturday, the biggest, brightest moon in about 20 years began peeking over the Eastern horizon.

The so-called “supermoon” was about 14 percent bigger and 30 percent brighter than normal, according to the National Aeronautics and Space Administration.

Because the moon’s orbit is oval, there is a point where it is the closest to the Earth, known as its perigee. The farthest point is known as its apogee, said Geoff Chester, an astronomer at the U.S. Naval Observatory in Washington, D.C.

On Saturday, the moon’s closest perigee of the year happened to occur within one hour of the monthly astronomical phase of the full moon, which together created the rarely seen increased illumination and size, he said.

“It will be the closest full moon we’ve had since 1993, so if you want to wait another 19 years or so for your next crack at it, then do so,” Chester said. “But it’s a great excuse to go out and look at the moon.”

Those who hoped to maximize their viewing experience will have set their sights on the distant horizon with objects, like mountains or buildings, in the foreground. As the moon rises behind those objects, it creates an optical illusion that makes it appear even bigger to the naked eye, Chester said.

“I often say the moon is looked over and overlooked. People don’t take that much time out of their busy lives, to appreciate it,” Chester said. “It’s an extraordinary thing.”