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.
This iridescent cloud was photographed last year from the
Top of the World Highway outside
Dawson City, in the
Yukon Territory in Northern
Canada.
Both
Sides Now:
See any shapes in the clouds?
