Look up Wednesday to see lunar eclipse
I want you to do anything you can make sure we have clear skies this Wednesday. Pray, mediate, hold a hair dryer to the sky.
We want the skies to be clear enough to see the last great total lunar eclipse until December, 2010.
It's even better this lunar time around because you don't need to lose your beauty sleep. This will be a prime time total lunar eclipse that will begin at 8:43 p.m. and be over by 12:09 a.m.
This should be quite a show as the moon slips into a ruddy hue during totality.
Lunar eclipses occur when the moon, in its orbit around the Earth, passes through the Earth's shadow opposite the sun, known also as the umbra shadow.
This can only happen during a full moon when our planet lies in a line between the sun and moon. But, this doesn't occur every time there's a full moon because the moon's orbit around the Earth is tilted by five degrees to the Earth's orbit around the sun.
Most of the time, the full moon misses the Earth's shadow. It either passes above or below it. Not this time, though. On Wednesday evening the moon forges right into the umbra shadow and we're in for some real eye candy!
Right around 8:43 p.m., you'll start to see the lower left side of moon begin to darken, and by 9 p.m. you'll really begin to see a big bite being taken out of it.
You can't help but notice that the shadow has a circular edge to it as it creeps across the lunar surface. Ancient Greek scientists saw this circular shadow of the Earth as proof the Earth was round. Now they were really ahead of their time!
From 10:01 until 10:51 p.m. the moon will be totally eclipsed but will still be visible. It could take on a bright orange hue or it might be bloody red. No one can really predict what hue the eclipsed moon will take on.
Only the shadow knows, the Earth's umbra shadow that is. The umbra shadow is not totally dark because some of the sun's light manages to get to get to it through our Earth's atmospheric shell. You can see this in the diagram above.
The sunlight that does get through is bent and strained as it comes through our atmosphere. All the blue and yellow components of the sun's light are scattered leaving just reddish part of the sun's light that bathes the eclipsed moon.
The shade of the red light reaching the moon depends on the combined atmospheric conditions of the area where the sunlight passes on its way to the moon. That makes it impossible to know exactly what shade of red or orange the moon will take on. but it's also part of the fun of a total lunar eclipse.
No matter what shade of red the moon takes on, it'll be beautiful and perfectly safe to look at. Unlike solar eclipses, you don't have to look through any special glass; although anytime you stare at a full moon it could effect you - maybe even make you a little "luny!"
Seriously, though, it's a wonderful experience to watch a total lunar eclipse, and through a pair of binoculars or a telescope it's even more fun.During totality you'll see the moon pass in front of or eclipse several stars. Not only does the moon rise in the east and set in the west just like the sun, but it also takes a much slower eastward migration among the background of stars as it orbits the Earth every month.Normally it's hard to see these stellar eclipses because of the brightness of the moon, but with the moon going through a 50 minute "power failure" it's a lot easier. Also, because the moon has no atmosphere, you'll see stars popping out of view on the eastern side of the moon and popping into view on the western side.And, to make this last lunar eclipse for almost two years extra special, the beautiful planet Saturn will be just to the lower left of the moon in a close celestial hug. Pan your telescope to the lower left of the moon and there will be Saturn's with it ring system.Saturn is now at its closest point to the Earth for this year and it will be featured in next week's Starwatch.Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of the book, "Pennsylvania Starwatch," available at bookstores and at his Web site www.lynchandthestars.com
