NASA's Explanation for this cloud:
NASA said the cloud was vapor left behind by the Terrier-Black Brant Rocket,
which was launched Tuesday morning from New Mexico.
The object left behind was a noctilucent cloud,
which appears in the sky when ice crystals about 50 miles or higher in the
atmosphere reflect the rays of the sun before it has risen above the horizon.
Photographed from Quail Creek
Green Valley, Arizona