Friday, November 7, 2003
Total lunar eclipse this Saturday
Saturday, November 8, will present us with a total lunar eclipse, which happens when the moon passes through the conical shadow cast by earth. The moon will be well positioned in the east to view this eclipse in early evening. When the moon enters the darkest part of the shadow, the umbra, it can be illuminated only by the sunlight that is refracted by earth's atmosphere. Since the atmospheric conditions are never the same for each eclipse, one can not predict how the moon will appear during totality. Often it appears deep reddish in color for the same reason sunsets appear reddish. Greater amounts of cloud cover would reduce this coloration. Even though this is not a rapid event, it may be interesting for family members to monitor the progress to discover how dark and colorful this eclipsed moon becomes.
Not much darkening will be visible until the moon passes from the outer lighter shadow called the penumbra, into the umbra. This begins about 6:30 p.m. when the moon is nearly due east at about 20 degrees above the horizon. When the moon moves completely into the umbra totality is said to begin and this will happen about 8 p.m. For this eclipse the moon does not stay totally eclipsed for long since it skims across the lower edge of the umbra instead of traveling along its diameter. By this time Saturn is just rising above the east-northeast horizon. Totality ends about 8:30 p.m. and the partial ends about 10 p.m.
Foss Farm with its low southeast horizon is an excellent place to observe the eclipse.
© 2003 The