Monday, December 20, 2010

Clarification on Tonight's Total Lunar Eclipse

I've had a phone call or two asking if the Kerry Wood Nature Centre is doing anything in honour of tonight's total lunar eclipse. Unfortunately, the only thing we are doing is encouraging people to get out and try to see it- it's not often that we have a clear shot at a total lunar eclipse, and especially not when it coincides with the shortest day of the year. Let me explain further...

Total lunar eclipses happen more frequently than you may think. I did a bit of research and found that there was a total lunar eclipse in 1967, 1978 and 1989; a spacing of 11 years between them. Since lunar eclipses are only visible on the night side of the Earth, we didn't see these particular eclipses when they happened. There were three total lunar eclipses within one year at the turn of the millenium: on January 21, 2000, July 16, 2000, and January 9, 2001. Only the first of these was partially visible from North America and, unfortunately for us here in Red Deer, only from the eastern parts. Australia, Africa and Asia, respectively, had the best seats for the other two, though many Canadians did travel to those countries to see them. (Coincidentally, my research also showed that Australia has the most common occurrence of total lunar eclipses altogether. North American sightings were very infrequent- one more reason to watch tonight!)

So what about tonight's eclipse?

As in Diane's previous post, the "show" doesn't start until 11:33 p.m. That would be 11:33 p.m. tonight, Monday, Dec. 20, which is a work/school night for most people (myself included). The total eclipse begins around 12:41 a.m. on Tuesday, Dec. 21, with totality finishing at approximately 1:53 a.m. tomorrow morning. But it doesn't end there! For all you diehard astronomers out there, the partial eclipse will go on for another hour and 8 minutes, with the partial eclipse ending around 3:01 a.m. on Tuesday, Dec. 21, which also happens to be winter solstice. It is the combination of a total lunar eclipse falling on winter solstice that is the once-in-400-years event the media is talking about. This, and the fact that total lunar eclipses are cool to watch, makes me think it's worth a little lost sleep.

Happy viewing!

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