Comments on: Up, up, and aurora

By: Robert

Robert — Sat, 14 Jul 2012 04:43:56 +0000

Sort of. In the upper atmosphere, the high-energy particles strike oxygen first, making it glow red. In the middle atmosphere, it generally finds ionic nitrogen first, which glows blue, while absorbing only part of the particle’s energy. The particle then goes on to hit oxygen again, which, at this energy level, glows green – making the blue-green colour we know. If they get to the lower atmosphere, (where lower is relative, of course: we are still high), it meets N2, normal nitrogen molecules, which gives a red-purple.
That is from uaf.edu, which is the first link in a google search for ‘aurora colour oxygen’.

By: Trish G

Trish G — Fri, 13 Jul 2012 21:13:55 +0000

I’ve also seen pictures of orange/reddish auroras. What makes those colors? And do the auroras in the southern hemisphere look the same as the ones in the north?

By: SkyGazer

SkyGazer — Fri, 13 Jul 2012 09:30:04 +0000

Amazing you are willing to put your kids up for grabs for some polar bears, in the Alaskan subzero wilderness, just to inspire them!
I applaude you!
But, serious. Very cool project. Nothing beats practical hands-on stuff.
Which is why I like this too:
http://www.wired.com/design/2012/07/diy-particle-accelerator/

By: Lars Bruchmann

Lars Bruchmann — Fri, 13 Jul 2012 08:46:30 +0000

Oxygen right? O2 radiates green when exited?

By: Adrian Morgan

Adrian Morgan — Fri, 13 Jul 2012 05:43:57 +0000

WOW! Documented proof! There really ARE dragons on the Sun! http://outerhoard.files.wordpress.com/2012/07/sundragon.png (This is an annotated screenshot from 1:20.)

Oh, and the science is cool, too.

By: Jason A.

Jason A. — Fri, 13 Jul 2012 03:30:29 +0000

@ #1. noen: It has to do with the type of molecule being excited up in the atmosphere. The green color is from atomic oxygen, which when excited emits lights of the wavelength we see as green. There are other colors due to other molecules, like a pink lower border and faint blue seen during high activity, and a high altitude red often seen from lower latitudes.

I have some pictures from one of their balloon launch nights if anyone is interested in what one of these rigs look like, see here: http://musubk.blogspot.com/2012/04/helium-balloon.html

Also, picking nits. Video says ‘nearly eye level’. The balloons are approaching 30km altitude. The lower edge of the auroras are around 100km.

By: Chas, PE SE

Chas, PE SE — Fri, 13 Jul 2012 00:18:37 +0000

We are doing something similar at the Adler Planetarium in Chicago. The Far Horizons” project has been launching balloons with insturment packages put together by CHS kids.

http://www.youtube.com/watch?v=CKFdZNg-WS4

(That’s me at 0:29)

And: http://www.adlerplanetarium.org/investigate/participate/farhorizons

Chas, “Magentahead”

By: noen

noen — Thu, 12 Jul 2012 19:54:36 +0000

Why are auroras green?