Skip to comments.Astronomy Picture of the Day -- A Quadruple Lunar Halo Over Spain
Posted on 12/02/2012 9:17:35 PM PST by SunkenCiv
Explanation: Sometimes falling ice crystals make the atmosphere into a giant lens causing arcs and halos to appear around the Sun or Moon. This past Saturday night was just such a time near Madrid, Spain, where a winter sky displayed not only a bright Moon but as many as four rare lunar halos. The brightest object, near the top of the above image, is the Moon. Light from the Moon refracts through tumbling hexagonal ice crystals into a 22 degree halo seen surrounding the Moon. Elongating the 22 degree arc horizontally is a circumscribed halo caused by column ice crystals. More rare, some moonlight refracts through more distant tumbling ice crystals to form a (third) rainbow-like arc 46 degrees from the Moon and appearing here just above a picturesque winter landscape. Furthermore, part of a whole 46 degree circular halo is also visible, so that an extremely rare -- especially for the Moon -- quadruple halo was actually imaged. The snow-capped trees in the foreground line the road Puerto de Navacerrada in the Sierra de Guadarrama mountain range near Madrid. Far in the background is a famous winter skyscape that includes Sirius, the belt of Orion, and Betelgeuse all visible between the inner and outer arcs. Halos and arcs typically last for minutes to hours, so if you do see one there should be time to invite family, friends or neighbors to share your unusual lensed vista of the sky.
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[Credit & Copyright: Dani Caxete]
Quick Poll: Have you ever seen a lunar halo?
I didn’t know it snowed in Madrid.
Your a better sighted man than I am, Gungha Din!
Circumscribed Halo...WTF?!? That I can’t make out at all.
46* “rainbow like” halo...check!
“Part of a 46* circular halo...”...HTH is that any different than the 46* halo itself???
I’d love to see Les Cowley at http://www.atoptics.co.uk/ take this apart, and highlight & explain each of the halos.
Kinda neat? LOL! You’re a master of understatement, Mr. Civilizations. [smiles]
Thank you for the spectacular APOD!
It does now, what with global warming and all.
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