Before going to bed tonight, don't forget to set your alarm clock. A total lunar eclipse early Saturday morning (Dec. 10) is expected to offer lucky skywatchers stunning views of a bright red, supersized moon.

A total lunar eclipse occurs when the Earth passes between the sun and the moon, casting the moon completely in shadow. The eclipse will start at around 7:45 a.m. EST (4:45 a.m. PST, 1245 GMT), when the shadow of the moon inches across the lunar disk.

The celestial show will be visible from parts of North America, with those in the western portions of Canada and the United States particularly well placed for the event. People in Alaska, Hawaii, Australia, New Zealand, and central and eastern Asia should also be able to catch sight of the reddened moon.

"For people in the western United States, the eclipse is deepest just before local dawn," NASA scientists said in a statement. "Face west to see the red moon sinking into the horizon as the sun rises behind your back. It's a rare way to begin your day."