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Unlike solar eclipses, which are only visible from specific places on Earth, lunar eclipses are visible from anywhere it is nighttime. Lunar eclipses don't occur every month because the plane of the lunar orbit is slightly tilted relative to the plane of the Earth's orbit, so the Earth, sun and moon don't always line up to put the moon in Earth's shadow. For the Jan. 31 lunar eclipse, viewers in some places will not be able to see the entire event because it starts near moonrise or moonset. Lunar eclipses are only visible on Earth's night side.

Observers in New York City will see the moon enter Earth's penumbra (the lighter, outer part of its shadow) at 5:51 a.m. on Jan. 31. The penumbra darkens the moon only a little; unless you're especially keen eyed, it is often difficult to notice. The moon will touch the umbra, the darker part of the shadow that gives the eclipse the distinctive look of darkening and reddening the moon, at 6:48 a.m. local time. But the moon sets only 16 minutes later, so New Yorkers will get to see only the first part of the eclipse. To see as much of the eclipse as possible, you'll want to be near a flat western horizon.

The situation gets better as you move west. Chicagoans will see the penumbra touch the moon at 4:51 a.m. local time, and it will still be a good 26.7 degrees above the horizon (about 53 times the apparent width of the full moon). The umbral eclipse will start at 5:48 a.m. local time, and by 6:16a.m., the moon will take on its characteristic blood-red color as it enters totality. Even so, it will set only minutes later, at 7:03 a.m., just as the sun rises.

In Denver and points west, the eclipse will start at 3:51 a.m. local time, with the umbra reaching the moon's edge at 4:48 a.m. The point of maximum eclipse, when the moon is deepest in the shadow of the Earth, will occur at 6:29 a.m. For the Mile-High City, the moon will set after the lunar eclipse ends at 7:07 a.m. local time, when the moon exits the umbra. Moonset will follow at 7:10 a.m.

Californians will have a better view of the end of totality, as the penumbral eclipse will start at 2:51 a.m. local time, and the partial eclipse will begin at 3:48 a.m. At 4:51 a.m. local time, the total phase will start, ending at 5:29 a.m. Totality will end at 6:07 a.m., and the moon will emerge from the umbra at 7:11 a.m. The penumbral shadow will pass after the moon is just below the horizon.

As one travels west across the Pacific, the lunar eclipse will occur earlier in the night; skywatchers in Hawaii will be able to see the entire thing from beginning to end, as will Alaskans and viewers in eastern Asia and Australia. On Jan. 31, people in Tokyo will see the lunar eclipse's penumbral phase start at 7:51 p.m. local time. The umbra will touch the moon at 8:48 p.m., and the maximum eclipse will be at 10:29 p.m. At 11:07 p.m., the moon will reach the opposite side of the umbra, and at 12:11 a.m. on Feb. 1, it will emerge and enter the penumbra. At 1:08 a.m., the eclipse will end for viewers in Tokyo.