Aurora

Photo credit - Deven Stross CC-BY-NC-ND

Photo credit – Deven Stross CC-BY-NC-ND

Cloud of the Day – Aurora

Aurora is not clouds. Clouds can’t form in the tenuous wisps of atmosphere found at the heights, approximately 90 – 1,000 kilometers, where aurora occurs. Therefore, it is wrong for me to call aurora the cloud of the day. Naughty me. It’s a meteorological phenomenon, and it’s beautiful. I’ll call it the cloud of the day if I want.

Photo credit - Alan C Tough

Photo credit – Alan C Tough

Photo credit - Andia Frh

Photo credit – Andia Frh

The Northern Lights, aurora borealis, were named in 1621 by Pierre Gassendi, a French scientist, priest and philosopher. Boreas was the Greek name for the north wind, and Aurora was the Roman goddess of the dawn. The Northern Lights are mirrored around the south pole by aurora australis, the Southern Lights.

Photo credit - 14jbella Click image for huge poster

Photo credit – 14jbella
Click image for huge poster

Photo credit - John Freddy

Photo credit – John Freddy

The aurorae work on the same principle as a neon lamp. Energized atoms release the excess energy as photons of light. In a neon lamp, the atoms are energized by electricity. In aurorae, nitrogen and oxygen atoms are energized by the solar particles that are trapped and funneled into the upper atmosphere by Earth’s magnetic field. When intense enough to be more than a whitish glow, the most common colors are green from oxygen and red from nitrogen. Other colors result from mixing of the main colors, or from variations in the excitation-release mechanism. For example, the rare blue that sometimes comes from nitrogen.

Photo credit - Aaron Kaase - Public domain

Photo credit – Aaron Kaase – Public domain

Although it might be interesting, there is no precipitation from aurora.

rjb

6 comments for “Aurora

  1. December 2, 2013 at 10:10

    If it is wispy like a cloud and beautiful like a cloud, I’d say it was a cloud.

    Am I all caught up? 🙂

    • December 2, 2013 at 10:24

      Well, if not then you made a pretty good dent in it.-)

      rjb

  2. December 2, 2013 at 10:12

    I just saw at the top of the page: Home of Elgin and Frances lol

    • December 2, 2013 at 10:26

      It is the home of Elgin and Frances. They’re the only reason greencomet.org exists.

      rjb

      • December 2, 2013 at 10:29

        We need to see more of them…
        I mean we need to see them. Can’t see more or them until we see them once.

        • December 2, 2013 at 10:37

          You mean see as in see? You’re right. We need an illustrator to flesh them out.

          rjb

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