Explanation:
What kind of cloud is that?
Last week, a
sunset rocket launch
lit up the sky and was photographed by
sky enthusiasts as far as hundreds of miles away.
The lingering result was a
photogenic rocket plume.
Not everyone who saw the resulting plume knew its cause to be a
Minotaur rocket
launched from
Vandenberg Air Force Base in
California,
USA.
The cloud was visible after sunset on 22 September.
Fuel particles and water droplets expelled from the rocket swirled in the
winds of the upper atmosphere, creating an expanding
helix.
The noctilucent plume was so high
that it still reflected sunlight, where lower clouds in the foreground appeared dark.
The above image
also captured part of the plume reflecting sunlight as a
rainbow or a colorful
iridescent cloud.
Below the launch plume is the planet
Venus.