Thursday, January 27, 2011

night shining clouds

On one of our winter holidays in Norway (Sjusjøen, 2008) we saw these clouds in the evening, after the sun had set. Today I am reading about (the apparently rare) night shining clouds on the Earth Observatory and wondering whether these would qualify as such. 
Anyway, they are beautiful. And next week we might see them again, we are looking forward to another great week in Nordseter. 

Here is the picture of the Earth Observatory, click on more to read the accompanying text:

After the Sun sets on a summer evening and the sky fades to black, you may be lucky enough to see thin, wavy clouds illuminating the night, such as these seen over Billund, Denmark, on July 15, 2010. Noctilucent or polar mesospheric clouds, form at very high altitudes—between 80 and 85 kilometers (50–53 miles)—which positions them to reflect light long after the Sun has dropped below the horizon. These “night-shining” clouds are rare—rare enough that Matthew DeLand, who has been studying them for 11 years, has only seen them once in person. But the chances of seeing these elusive clouds are increasing. (...)

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