Mange har sikkert set farveforstærkede billeder af Månen, som dette:

Hvis man gør det samme med lysende natskyer ser det sådan ud:

eller sådan:

Jeg har fået denne forklaring på farverne (citat):
Hello Jesper,
NLCs are visible by light that their crystals scatter. The incoming sunlight is sometimes reddened by a grazing passage though the lower atmosphere – this makes NLCs near the horizon red hued. The light from NLCs is partly absorbed by stratospheric ozone
http://www.atoptics.co.uk/highsky/hozon.htm
and this adds a blue tint to them. Combinations of the red/yellows and blues will give sone apparent greenish tints.
Regards,
Les
Les Cowley
Atmospheric Optics – http://www.atoptics.co.uk
Optics Picture of the Day – http://www.atoptics.co.uk/opod.htm
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