Lunar Eclipse

The year's first total eclipse of the moon will last an unusually long time, a rare celestial treat for a wide swath of the globe.

Except if you're in the United States and Canada. North America will be left out of Wednesday's lunar spectacle, which will be visible from start to finish from eastern Africa, central Asia, the Middle East and western Australia – weather permitting.

The period when Earth's shadow completely blocks the moon – known as totality – will last a whopping 1 hour and 40 minutes. The last time the moon was covered for this long was in July 2000, when it lasted 7 minutes longer than that.

The full moon normally glows from reflected sunlight. A total lunar eclipse occurs when the moon glides through the long shadow cast by the Earth and is blocked from the sunlight that illuminates it.

As the moon plunges deeper into the Earth's shadow, the disk will appear to gradually change color, turning from silver to orange or red. This is because some indirect sunlight still reaches the moon after passing through the Earth's atmosphere, which scatters blue light. Only red light strikes the moon, giving it an eerie crimson hue.

It's difficult to predict the exact shade the moon will take, which will depend on how much dust and clouds are in the atmosphere during the eclipse.

Since the moon will pass close to the center of the Earth's shadow, the total eclipse phase will be longer than usual, said NASA eclipse expert Fred Espenak at the Goddard Space Flight Center in Maryland.

The entire eclipse will last a little over 5 1/2 hours. Observers in Europe will miss the first part of the show because it will occur before the moon rises. Eastern Asia and eastern Australia won't catch the final stages, which will happen after the moon sets. Portions of South America will be able see the moon entirely shrouded.

Unlike solar eclipses, lunar eclipses are safe to watch with the naked eye.

Keith Gleason, who runs the Sommers-Bausch Observatory in Boulder, Colo., is disappointed that he will not have a ringside seat to the upcoming eclipse. The last total lunar eclipse visible from the U.S. occurred on Dec. 21, 2010, which coincided with winter solstice and was widely observed. Some 1,400 people showed up for a viewing party at the observatory.

"We had an absolutely glorious time," he said.

The next total lunar eclipse will fall on Dec. 10 with best viewing from Asia and Australia. The moon will be completely blotted out for 51 minutes. Only parts of the U.S. including Hawaii and the Pacific Northwest will catch a glimpse.

The rest of the continental U.S. will have to wait until April 15, 2014 to witness a total lunar eclipse.