Supermoon Lights Up Sky, Impresses Skywatchers

Saturday's full moon was the biggest in 18 years.

ByABC News
March 20, 2011, 10:49 AM

March 20, 2011— -- Did last night's rare "supermoon" live up to its hype?

If the commentary online is any indication, those who had clear skies were not disappointed with the brilliant full moon that lit up the sky.

On Twitter, Facebook and Flickr, skywatchers around the world posted pictures and reactions to the the biggest full moon in nearly decades.

During the so-called "supermoon," the moon wasn't just at its closest approach to Earth in its elliptical orbit, it was closer than it has been in 18 years.

After the sun set for East Coasters, #supermoon started trending on Twitter, as people started tweeting about the event. Many even uploaded snapshots of their supermoon views to the photo-sharing website Flickr.

"It's a bird- it's a plane- no, it's Supermoon!," said one Facebook user.

"the supermoon was super beautiful last night," posted another.

The commentary even continued into Sunday morning.

"#supermoon that moon last night was crazy almost thought it was the sun but the sky was black!,'' posted someone on Twitter.

Full moons come in different sizes because of the elliptical shape of the moon's orbit -- one side of the ellipse is about 31,000 miles closer to Earth than the other. When the moon is closest to Earth (at its perigee), it is 14 percent larger and 30 percent brighter than when it's farthest from the planet (at its apogee).

For weeks, Saturday's so-called "supermoon" sparked interest online, with astrologers and amateur astronomers speculating that the extra-large full moon could lead to unusual weather. After Japan's earthquake, some even wondered if the supermoon contributed to the event.