Saturday, December 18, 2010

Total Lunar Eclipse, 12/21/2010

Partial phase begins: 1:32 a.m.
Total phase begins: 2:40 a.m.
Total phase ends: 3:54 a.m.
Partial phase ends: 5:02 a.m.

Tuesday morning, our moon enters the Earth’s shadow becoming totally eclipsed. The entire lunar face is enveloped in darkness beginning at 2:40 a.m. and lasting until 3:54 a.m. Then, a silver sliver emerges from the shadow’s edge eventually growing into the bright full moon by 5:02.

During the eclipse, the moon will be difficult to see since it lies, not in sunlight, but in the same shadow that gives us our night. We happen to stand within its first few feet, while the moon moves 230,000 miles away in the shadow’s gently tapering cone.

Take particular note of the color of the dark orb. Due to the small amount of sunlight refracting through the Earth’s atmosphere, the moon won’t be black, but a shade of dark red. It will likely show a subtle 3D effect, making an eerie scene.

All of this can be much more easily seen through binoculars. When the darkened moon reaches totality, look at the region immediately around it. To its upper left, a dimly glowing patch of light can be glimpsed. That is the galactic star cluster M35, which will be quite invisible once the brightening moon begins to exit the shadow.

As astronomical events go, total lunar eclipses aren’t particularly rare, but they aren’t common, either. The next total lunar eclipse visible from southwest Virginia is April 15, 2014 at 3:00 a.m.

Such is our view from Earth...