July 8, 2014
The stars above are ancient, but your chance to be here is exquisitely temporary.
Iridescent Clouds over Thamserku
Birthday · July 8, 2014
A little universe, just for you
Your date.
Ready to give.
Free PNG · 1080 × 1350 · No account needed
Image rights and credit requirements apply when sharing or reusing imagery.
Date & occasion only
Change the year
APOD published July 8, 2014. Credit: Oleg Bartunov. A publication-date match, not a photo taken on your date. Independent of NASA.
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. Follow APOD on: Facebook, Google Plus, or Twitter
Image credit: Oleg Bartunov