Volume: 02, Issue: 17 10/20/2004 
In this lunar eclipse viewed from Merritt Island, Fla., the full moon takes on a dark red color because it is being lighted slightly by sunlight passing through Earth's atmosphere. Photo courtesy NASA/KSC.
Expand Image
Diagram illustrating how lunar eclipses are formed. Image courtesy Fernbank Science Center.
Expand Image
Printer Friendly Version
Other Articles in This Issue:
Astronomers Discover Planet Building is Messy Process
Astronauts Begin Dress Rehearsals for Shuttle Return to Flight
Light Shed on Genesis Mishap
Chat with Astronaut Col. Mark Lee

Total Lunar Eclipse Nearing

A total lunar eclipse is expected to begin at 8:14 p.m. CDT on Wednesday, Oct. 27, 2004. During this lunar eclipse, the Moon is expected to pass through Earth’s shadow for more than three hours.

At 8:14 p.m. CDT, observers will notice the full moon beginning to be covered by Earth’s shadow. By 9:23 p.m., the Moon will be completely eclipsed. The Moon will remain eclipsed until 10:45 p.m., when it will begin to slip out of Earth’s shadow. By 11:54 p.m., the Moon will exit the dark part of Earth’s shadow, and the full moon will appear normal again.

An eclipse of the Moon occurs when a full moon, in its monthly path around the Earth, moves into Earth’s shadow. Because the Moon’s motion in its orbit is from west to east, the eastern side of the Moon enters the shadow first. Since the Moon shines only by reflected sunlight, we see it gradually darken as it enters Earth’s shadow.

During the eclipse, the Moon will appear red. While it remains completely within Earth’s shadow, some indirect sunlight still manages to reach and illuminate it. The small amount of light that does hit the Moon comes around Earth after bending through the planet's atmosphere. This light is deep red or orange for the same reason that sunsets are red. Rays of white sunlight passing through the atmosphere are subject to "scattering." Blue light sprays off in all directions (this is why the daytime sky glows blue), but the red light is relatively unaffected, so it continues through.

Unlike solar eclipses, lunar eclipses are perfectly safe to view with the naked eye and don’t require any special protection. The brightest object that can be seen is the full moon itself, just before or just after the eclipse occurs. To get the best view of this eclipse, avoid bright lights. The best viewing location is a dark, open space far away from city or highway lights.

To learn more, visit:

© 1997-2017 Space ExplorersTM, Inc. All Rights Reserved.
  Archived Issues Issue Index Contact Feedback Subscribe Home