September 22, 2009
Noctilucent clouds are clouds that naturally occur at 50 miles above the earth and glow at night. Last weekend, NASA made one for themselves.
The experiment created a man-made noctilucent cloud using the fourth stage of a NASA Black Brant XII suborbital sounding rocket that spewed exhaust particles 173 miles (278 km) above Earth. Ground-based radar and camera stations recorded the resulting cloud’s formation and illumination. The U.S. Naval Research Laboratory and Department of Defense’s Space Test Program oversaw the launch, which it called the Charged Aerosol Release Experiment.