A "blood moon" is expected to make a brief appearance Saturday morning for the shortest total lunar eclipse of the century.
At 6:16 a.m. ET, the "bright full moon will turn a shady red," NASA said in a press release. The total eclipse will last a mere five minutes, the space agency said.
"The moon will be moving into the shadow of the earth," Mitzi Adams, a NASA spokesperson explained in a teleconference. "As it moves deeper into the shadow, the shadow will appear to move across the disk of the moon until it’s totally immersed and the entire moon will appear reddish brown."
On the West Coast, the total eclipse will be visible before dawn at 4:58 PT. Early-risers in eastern Canada will have a chance of seeing the beginning stages of the spectacle, or partial eclipse, at 6:16 a.m. ET. If skies are clear, the moon will appear low in the west of the sky, NASA said.
Unlike other night-sky phenomena, Saturday's eclipse should be clearly visible even without a telescope and within city limits, Adams said.
"This type of astronomical event is not 'best observed' in a dark night sky. You can certainly see this in a city as long as you have a view of the western horizon," she said.
Unfortunately, the current forecast isn't promising. Toronto is expecting partial cloud cover at the time of the eclipse, Ottawa skies are expected to be cloudy, Montreal is expecting snow, and Halifax and Vancouver are both expecting rain.
Outside of Canada, most of the United States will also have a chance to see either a partial or full eclipse, while sky-watchers in India, western China, and Russia could spot the end stages of the eclipse just after their sunset.
Lunar eclipses occur when the moon passes into the earth's shadow. When this happens, the earth blocks the sun’s light from directly hitting the moon. A total eclipse occurs when the moon completely enters the darkest part of the earth’s shadow, the umbra.
This does not mean the moon goes completely black, however. Some light does indirectly reach the moon, but it has to pass through the earth’s atmosphere, which filters out the blue light. This causes the blood moon's red tint.
Saturday's lunar eclipse is the third in the "tetrad" series of eclipses. The fourth and final tetrad eclipse will be Sept. 28.
Viewers are invited to ask questions about the eclipse by tweeting Mitzi Adams, a NASA astronomer in Alabama, at @NASA_Marshall, using the hashtag #eclipse2015. Adams will be online starting at 6 a.m. ET Saturday.
