Total lunar eclipse will occur Thursday

This article submitted by Linda Stelling on 1/19/00.

The first total lunar eclipse of the new year will occur on Thursday, Jan. 20, starting around 9 p.m.

According to the Astronomical Society of Canada, this will be the first total lunar eclipse in nearly three years and will be seen throughout the United States. The total phase will last about 78 minutes.

The complete list of eclipse times are:
Moon enters outer shadow: 8:03 p.m.
Moon enters inner shadow: 9:01 p.m.
Totality begins: 10:05 p.m.
Middle of eclipse: 10:44 p.m.
Totality ends: 11:22 p.m.
Moon leaves inner shadow: 12:24 a.m.
Moon leaves outer shadow: 1:24 a.m.

Some of the shading may be visible until about 1 a.m. After that the moon will appear normal even though it is still partly within the Earth's shadow.

Watching the eclipse can be an enjoyable event. If you have a pair of binoculars, be sure to use them.

According to the Lake Afton Public Observatory in Wichita, Kan., during the total phase of the eclipse, the moon does not completely disappear. This is due to sunlight that is bent by Earth's atmosphere onto the moon. Since red light is less likely to be scattered by the atmosphere, the moon will appear reddish during totality. How light or dark it is depends on how much junk is in the atmosphere. The more stuff in the atmosphere, the darker the moon will appear.

As pleasing as the eclipse is to observe, some people may want to photograph it. It is possible to take pictures with a 35 mm single-lens reflex camera and a telephoto lens.

The observatory recommends using 800 or 1000 speed film. If you're using a different speed, you'll have to adjust your exposure.

It is difficult to predict how dark the moon will be during totality. If the moon appears dark, try exposures longer than those recommended.

Suggested exposures:
Full moon 1/500@f/16
Pre partial eclipse: 1/125@f/16
Partial eclipse: 1/8@f5.6
Beginning of totality: 1/8@f2.8
Middle of eclipse: 1/2@f2.8
End of totality: 1/8@f2.3

Tips: 1) Make sure you use a fast film for the total portion of the eclipse; 2) With a 55 mm lens exposures longer than about 10 seconds will show streaking. The longer the focal length of your lens, the sooner streaking will become noticeable; and 3) If you have a 2X or 3X tele-extender for your lens, you may want to use it.

During the total phase, the exposures with the extender may be long enough to cause trailing so you may want to take some photos without it. Four partial solar and two total lunar eclipses occur in 2000 as follows:
Feb. 5: Partial solar eclipse
July 1: Partial solar eclipse
July 16: Total lunar eclipse
July 31: Partial solar eclipse
Dec. 25: Partial solar eclipse

Links to sites about the eclipse: Sky & Telescope Magazine  •  Lake Afton Public Observatory.

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