Saturday, October 16, 2004

Green Flash

The sky was really clear today and it was a little windier than usual. Good sunburn weather.

That's why I do my bike rides first thing in the morning. Down at the south end, the sea was an incredible blue today.

So at 6pm, we jumped in the car and headed north about a half mile to see if we could see the green flash when the sun set. The sun set about 6:14 and there was a nice green flash. I snapped a picture with my camera and Celestron C90 telescope. I flipped the image vertically, because it is upside down in the telescope. I also cropped it and then sharpened it, but didn't mess with it in any other way. This is exactly how it looked in the LDC panel on the camera.

You can tell the sky was very clear because there is even some blue at the edges of the sun's image. Usually the blue wavelengths are filtered out by the atmosphere. Often the greens are too, but the sky today was nice and clear.

You can click on the picture to make it bigger. Posted by Hello

A google search on "green flash" turns up lots of hits. Here is a brief explanation on a NASA web page. Here is a very rigorous treatment of the physics involved. And here are a zillion green flash links.

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