Yesterday evening, March 26th, sky watchers in southern California, Arizona and Nevada were surprised when they saw swirls of colorful gas looping through the sunset sky. This wasn’t a rocket launch at Vandenberg AFB. Nope, this very colorful and iridescent cloud was produced by the test launch of a Trident II (D5) missile from a submarine off the coast of San Diego, which was scheduled for March 26-27.
What caused the pearly colors? Water droplets and bits of unburnt fuel from the missile’s exhaust froze in the cold upper atmosphere. When high-altitude sunlight hit the icy crystals, they glowed pastel yellow, red and blue – a phenomenon known as iridescence.