Make plans now!

from Skyscrapers, Inc.

North Americans can see a total lunar eclipse on December 20-21.

Says NASA:

The last lunar eclipse of 2010 is especially well placed for observers throughout North America. The eclipse occurs at the Moon’s descending node in eastern Taurus, four days before perigee.

The Moon’s orbital trajectory takes it through the northern half of Earth’s umbral shadow. Although the eclipse is not central, the total phase still lasts 72 minutes. The Moon’s path through Earth’s shadows as well as a map illustrating worldwide visibility of the event are shown in Figure 4. The timings of the major eclipse phases are listed below.

Penumbral Eclipse Begins:   05:29:17 UT
Partial Eclipse Begins:     06:32:37 UT
Total Eclipse Begins:       07:40:47 UT
Greatest Eclipse:           08:16:57 UT
Total Eclipse Ends:         08:53:08 UT
Partial Eclipse Ends:       10:01:20 UT
Penumbral Eclipse Ends:     11:04:31 UT

For those who don’t set your clock to universal time, you can convert to your local time here. For those who are not into precision, figure to be outside around midnight on the East Coast and 9:00 p.m. on the West Coast.

Update [12/19]: Yes, it is very tricky given that the event will take place on December 20 for part of the time on the West Coast but on December 21 for the entire time on the East Coast. And yes, I should have been more precise given that I know my readers have many things to do around that time, December 21 being the Winter Solstace and all. So here’s a more precise explantion:

The “prenumbral eclipse” begins when the moon passes through that part where only a part of the light is obscured. That will occur at:

12:29:17 am on December 21 on the East Coast and
9:29:17 pm on December 20 on the West Coast.

The moon will begin to pass through the inner shadow, the “umbra,” at

1:32:37 am on December 21 on the East Coast and
10:32:37 pm on December 20 on the West Coast.

The full eclipse will begin at

2:40:47 am on December 21 on the East Coast and last until 3:53:08 am.
11:40:47 pm on December 20 on the West Coast and last until 12:53:08 am on December 21.

A graphic representation of how this all works can be seen by clicking the “Figure 4” hyperlink in the quotation from NASA above.

I am completely confident that the public school systems for those living in the Central and Mountain Time Zones are adequate to have taught skills necessary to convert the above to local times. I base this confidence on the fact that most people are able to watch or TiVo their favorite TV program based on promos that only give Eastern and Pacific Times. If, however, all this is too complex or if you rely on TV Guide to make conversions and thus have had your skills degraded from non-use, I suggest telephoning your local Fox affiliate for assistance. Happily at this time of year Arizona joins the rest of the Mountain Zone so no special calculations are required there.

This will be the only time that a complete lunar eclipse takes place (completely on the East Coast and partially on the West Coast) on the same day as the Winter Solstace for the next 84 years. There is no particular significance to that fact, however.

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