Friday, December 17, 2010

Winter Solstice Lunar Eclipse

December 21, 2010 - Winter Solstice. The shortest day and longest night of the year. This means, essentially, that because of the tilt of the earth, the sun is the furthest south it will be all year. And right now, the moon is also at its northernmost point in its rotation around the earth. According to the experts, this will be the northernmost lunar eclipse in centuries!

The last time a lunar eclipse happened on the winter solstice was in 1554. And according to EarthSky, there won’t be another total lunar eclipse this far north on the sky’s dome until December 21, 2485.

If you want to know if and when you can see the eclipse, check out this site - it talks all about it and lists the best times to see it. In my area, Mountain Time, it will be totally eclipsed at 12:41 am on December 21. Total eclipse ends at 1:53 am. So it's a good full hour of lunar eclipse viewing.

What is a lunar eclipse?

When the sun, earth and moon all align and the moon passes through earth's shadow you get a lunar eclipse. The only time this can happen is during a full moon. I'm a visual person, so here is a diagram showing how this works.

So essentially, the moon is at just the right angle to pass into earth's shadow. During most full moons, the moon is still directly across from the sun, however it is not lined up with the earth allowing the earth's shadow to pass over it.

Now, unlike what you might expect when this happens, the moon does not go totally black, or even kind of gray. It turns a beautiful, deep orange/red. Why is that? Here is a little explanation from NASA about why this happens:

Why moon will appear red

If you were to stand on the moon's surface looking up at the sky, you would see Earth hanging above, nightside down, and completely hiding the sun behind it.
Rather than being completely dark, the Earth's rim would appear as if it were on fire. Around its circumference, you would be seeing every sunrise and every sunset in the world at the same time.
This surrounding light will actually beam right into Earth's shadow, giving it a rusty glow.
From the Earth, the moon would appear as a giant red orb because the only sunlight visible is refracted through the Earth's atmosphere.
 Source: NASA

Pretty cool, eh?

So pull on your mittens, grab your hot chocolate, and head outside to watch this beautiful, rare event. I know I'll be there. Of course, I don't work Monday or Tuesday, so sleep doesn't really matter. And if it's cloudy, or you just don't feel like facing the cold, check out the SLOOH Space Camera link on my side bar. You can watch it from there.


"Ranger" Kim said...


Jenny said...

I'm so glad you posted this!!! I didn't know and I am so EXCITED!!!
I hope the clouds will cooperate.