2. POLAR STRATOSPHERIC CLOUDS
Polar Stratospheric Clouds exist at very high altitudes
within Earth’s stratosphere (around 70,000 ft).
Clouds normally do not form in stratosphere because of
its extreme dryness. During winters however in high
latitudes temperature falls low enough to permit
formation of clouds in stratosphere. These clouds appear
colorful when sunlight is refracted off ice crystals. They
are only noted during sunrise and sunset.
5. MOONBOW
A moonbow is a rainbow produced by
moonlight rather than from direct
sunlight. Moonbows are usually
faint. Because of the faint light
usually it becomes difficult for the
human eye to discern colors in a
moonbow and as a result they often
appear to be white. However, all
colors of a moonbow do appear in
