TONIGHT: EARTH CASTS SHADOW DURING LUNAR ECLIPSE

By the light of the silvery moon, star gazers tonight will be able to see the earth's shadow during a lunar eclipse.

Craig Joseph, of the Southeast Missouri State University physics department, "We see the moon because it is illuminated by the sun. During a lunar eclipse, the earth gets in the way. Basically it's a big rock casting a shadow.

"The interesting thing is that this is the shadow of the planet you're standing on, and it's a big shadow."

The physics department will provide binoculars and set up several telescopes at the north end of the Rhodes Hall parking lot on campus.

But Joseph emphasized, "You won't need a telescope. Anyone who can see the moon can watch the eclipse occurring."

"If you use binoculars or a telescope see a lot more detail. But you can still see the full moon very clearly with the naked eye."

The eclipse will begin at 10:26 p.m., with mid-eclipse at 11:57 p.m. when 68 percent of the moon will be blocked from view. It will end at 1:27 a.m.

"What you will see early in the evening is a normal full moon," he explained. "A lunar eclipse always occurs around the full moon."

"Sometimes the lunar eclipse can be quite dark," Joseph said. "Other times you can still faintly see the part of the moon in shadow. Sometimes it is almost a blood-red color because some of the rays of the sun are refracted through the earth's atmosphere. It depends mostly on atmospheric conditions on earth."

Joseph said currently there is a lot of volcanic ash in the earth's atmosphere which may cause this eclipse to be very dark.

Tonight's eclipse will cover about three-fourths of the moon's surface. Joseph said primarily, the upper portion of the moon will be eclipsed.

"Looking at the moon, it will begin to darken on the upper left hand side," he said. "The earth's shadow will skim the upper portions of the moon. The last portion to reappear will be the upper right hand portion."

"A solar eclipse occurs when the moon's shadow falls on the earth. That happens much less frequently than a lunar eclipse," he said.

The last total lunar eclipse visible from the Midwest was in August 1989. Joseph said that a total lunar eclipse visible in the Midwest will occur Dec. 9. Tonight's eclipse is not a total eclipse.

"Sometimes you have two eclipses in the same year, like this year. Other times go several years without any," he said.

Scientists will study the surface of the moon and the rate of cooling caused by the eclipse, but mostly a lunar eclipse provides a spectacle to watch.

"It's an interesting sight in nature. A lot of people think there is something very mysterious about eclipses," Joseph said. "Really it's nothing more than a big rock out there passing into a shadow."