NASA just launched the "AIM" satellite to study noctilucent clouds (very high altitude clouds seen in reflected sunlight long after sunset), and why they're becoming more common. These clouds increase the reflectivity of the Earth, and are therefore important to understand man-made climate change.
A few noctilucent clouds are caused by rocket launches -- here are some cool examples. The top photo, of a Minotaur rocket launch in 2006 from Vandenberg Air Force Base, was taken by Steve West in Tucson. I saw those clouds, too (in a Target parking lot) -- they really were that spectacular! Drivers pulled over and got out to gawk.
Here's another fanastic launch-cloud photo by Steve West, this one of a THAAD missile test.