Posted on 09/06/2012 8:11:43 PM PDT by SunkenCiv
Explanation: In this serene night skyscape, the Milky Way's graceful arc stretches over prominent peaks in the Italian Alps known as Tre Cime di Lavaredo. A 180 degree wide-angle panorama made in four exposures on August 24, the scene does look to the north and the sky is suffused with an eerie greenish light. Still, the subtle glowing bands are not aurorae, but airglow. Unlike aurorae powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to chemiluminescence, the production of light in a chemical reaction, and found around the globe. The chemical energy is provided by the Sun's extreme ultraviolet radiation. Like aurorae, the greenish hue of this airglow does originate at altitudes of 100 kilometers or so dominated by emission from excited oxygen atoms. More easily seen near the horizon, airglow keeps the night sky from ever being completely dark.
(Excerpt) Read more at 129.164.179.22 ...
[Credit & Copyright: Tamas Ladanyi (TWAN)]
Ba-oring! ;')
|
I didn't find it so at all. Anytime I learn something, it's a good thing. Since I had never even heard of airglow before, I found it interesting.
I’m with you.
I prefer the Hubble Images!
BUT it is a pretty picture, nonetheless.
Did this come too soon on the heels of the last air glow picture to suit you, dear?
I do sort of wish that we’d get some more space pictures between the air glow ones.
And I have been in the high desert on an overcast night where I could not see my hand in front of my face in the all-over, black-ink darkness, and there was no air glow or any other kind of glow to help with it at all.
OMG so pretty!
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.