by APOD Robot » Tue Jul 08, 2014 4:05 am
Iridescent Clouds over Thamserku
Explanation: Why would a cloud appear to be different colors? A relatively rare phenomenon known as
iridescent clouds can show unusual colors vividly or a whole
spectrum of colors simultaneously. These
clouds are formed of small
water droplets of nearly uniform size. When the
Sun is in the right position and mostly hidden by thick clouds,
these thinner clouds significantly
diffract sunlight in a nearly coherent manner, with
different colors being deflected by different amounts. Therefore,
different colors will come to the observer from slightly
different directions. Many clouds start with uniform regions that could show
iridescence but quickly become too thick, too mixed, or too far from the Sun to exhibit striking colors. The
above iridescent cloud was photographed in 2009 from the
Himalayan Mountains in
Nepal, behind the 6,600-meter
peak named
Thamserku.
[/b]
[url=http://apod.nasa.gov/apod/ap140708.html][img]http://apod.nasa.gov/apod/calendar/S_140708.jpg[/img] [size=150]Iridescent Clouds over Thamserku[/size][/url]
[b] Explanation: [/b] Why would a cloud appear to be different colors? A relatively rare phenomenon known as [url=http://www.atoptics.co.uk/droplets/irid1.htm]iridescent clouds[/url] can show unusual colors vividly or a whole [url=http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html]spectrum[/url] of colors simultaneously. These [url=http://en.wikipedia.org/wiki/Cloud_iridescence]clouds[/url] are formed of small [url=http://www.atoptics.co.uk/droplets/clouds.htm]water droplets[/url] of nearly uniform size. When the [url=http://apod.nasa.gov/apod/sun.html]Sun[/url] is in the right position and mostly hidden by thick clouds, [url=http://cimss.ssec.wisc.edu/wxwise/class/iredsnce.html]these thinner clouds[/url] significantly [url=http://www.exploratorium.edu/snacks/diffraction/index.html]diffract[/url] sunlight in a nearly coherent manner, with [url=http://www.youtube.com/watch?v=2TCytXKQUoA]different colors[/url] being deflected by different amounts. Therefore, [url=http://en.wikipedia.org/wiki/Iridescence]different colors[/url] will come to the observer from slightly [url=http://www.kaushik.net/avinash/wp-content/uploads/2010/02/many_different_directions.jpg]different directions[/url]. Many clouds start with uniform regions that could show [url=http://www.meteoros.de/iris/irise.htm]iridescence[/url] but quickly become too thick, too mixed, or too far from the Sun to exhibit striking colors. The [url=https://www.flickr.com/photos/obartunov/4085266152/]above iridescent cloud[/url] was photographed in 2009 from the [url=http://en.wikipedia.org/wiki/Himalayas]Himalayan Mountains[/url] in [url=http://en.wikipedia.org/wiki/Nepal]Nepal[/url], behind the 6,600-meter [url=https://www.youtube.com/watch?v=-3Cf8Vy7ncY]peak[/url] named [url=http://en.wikipedia.org/wiki/Thamserku]Thamserku[/url].
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