Tonight, we'll be treated with what will be our last total lunar eclipse until March 3, 2007, and the last eclipse that will be easily viewed throughout the entire continental U.S. until February 21, 2008. Get it while it's hot. ;-)
The partial and total phases of the eclipse will be visible in the evening sky throughout most of the Americas. In the western third of the continental U.S., the moon will already be very faintly eclipsed when it rises. In Alaska the moon will already be fully eclipsed at moonrise.
Europe and Africa also get a view of this eclipse, but at a less convenient time: the early hours of Thursday morning.
A total eclipse of the moon occurs when the full moon passes through the inner portion of Earth's shadow, known as the umbra. The umbra blocks all direct sunlight from reaching the moon. The penumbra, or outer shadow, blocks some, but not all of the sun's light.
Not until the night of February 20, 2008, will the entire population of the continental U.S. be able to step outside and catch an eyeful of an eclipse before crawling into bed for the night.
In the U.S. the March 3, 2007, event will be visible from the eastern half of the nation while the August 28, 2007, eclipse is best viewed from the West during the wee hours of the morning, Espenak said.
Wednesday's eclipse gets underway in earnest at 9:14 p.m. eastern time, when the moon's eastern edge begins moving through the umbra, causing it to darken to a reddish hue.
Totality, when the entire moon is inside the umbra, should begin at 10:23 p.m. ET and last an hour and 22 minutes until 11:45 pm ET. This duration of totality is on the "long side of average."
By contrast, totality for the last widely visible eclipse in the U.S., on November 9, 2003, lasted only 24 minutes. The maximum totality duration possible is an hour and 47 minutes, which last occurred July 16, 2000.
After totality, a partial eclipse ensues as the moon slips out of the umbra. Excluding the faint, penumbral phases, the entire event lasts 3 hours and 40 minutes, with the partial eclipse ending at 12:5.4. am ET on Thursday.
Unlike solar eclipses, a lunar eclipse is safe to look at with the naked eye—no special filters or glasses are required to block out harmful rays of light. Astronomers suggest looking at the moon through binoculars and telescopes to enhance the colors.
The only thing that is critical for viewing a lunar eclipse is a view unobstructed by tall buildings, trees, or mountains.
North Americans will be treated to the fall and winter constellations during the eclipse. The moon will be in southern Aires, Pegasus will be to the west, and Taurus and Orion will be to the east.