Total eclipse of moon last night

February 21, 2008 11:01:20 AM PST
There was quite a sky show over the Chicago area Wednesday evening. The sun, the moon and the Earth teamed up to create an out of this world experience Wednesday night: a total eclipse of the moon.

To see the lunar eclipse, Chicagoans looked east, out over the lake. Just after 7:30 the action began. The Earth's shadow gobbles up the moon like Pacman. It's something that most of us have seen at least a few times.

"You can see a total eclipse every six months, or two times a year when you can see eclipses of the moon. But this one is kind of rare because it'll be more than two years before we see another total eclipse of the moon," said Dr. Mark Hammergren, Adler Planetarium Astronomer.

The total eclipse was seen over all of North America, even up into Alaska.

"It takes a couple hours for the entire thing to progress. From 7:43 until a little after 11 p.m. tonight is when the totality, the total eclipse lasts," said Hammergren, on Wednesday.

The moon will, in a sense, turn a bit red. And that's because, if you picture yourself standing on the moon and looking back at the Earth, the sun's rays bend around the Earth, similar to sunset rays. Since the atmosphere filters out blue light, the indirect light that reaches the moon transforms it into a reddish or orange tinge, depending on how much dust and cloud cover are in the atmosphere at the time.

"You would see the Earth passing directly in front of the sun. And you would see the dark Earth surrounded by this radiant light, a real reddish light. And that reddish light would be the sunlight bent by the Earth's atmosphere and falling on the moon," said Hammergren.

So every once in a blue moon, we have a red moon.