SPACEX MAKES A NOCTILUCENT CLOUD: NASA’s AIM spacecraft is monitoring a veritable explosion of natural noctilucent clouds (NLCs) around the Arctic Circle. Yesterday, June 29th, SpaceX created an NLC of its own by launching a rocket over Florida. Mike Deep photographed the jellyfish-shaped cloud from the roof of the Vehicle Assembly Building at Kennedy Space Center:
“SpaceX launched a Falcon 9 rocket carrying supplies to the ISS,” explains Deep. “The liftoff time was pre-dawn at 5:42am, which meant the rocket lifted off in darkness and ascended into sunlight at extreme altitude, resulting in noctilucent clouds and a jellyfish plume from the second stage.”
Natural noctilucent clouds form when summertime wisps of water vapor rise to the top of Earth’s atmosphere and crystallize around specks of meteor smoke. Mesospheric winds gather the resulting ice crystals into rippling clouds of electric-blue around the Arctic Circle.
Manmade noctilucent clouds, on the other hand, can form from ice crystals in a rocket’s exhaust. These crystals can catch the rays of the distant rising sun, producing luminous forms in the dark pre-dawn sky. Sample photos may be found here, here and here.
SpaceX’s noctilucent cloud was fleeting. It’s gone now. But the natural variety may still be seen from high-latitude locations in Europe and Canada. Observing tips: Look west 30 to 60 minutes after sunset when the sun has dipped well below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.