This noctilucent cloud video is the perfect vacation for your brain

Noctilucent clouds are some of the most poorly understood meteorological phenomena on Earth. High-hanging and electric-blue in hue, the ethereal, night-shining formations feature prominently in this beautiful film by photographer P-M Hedén. » 8/13/13 1:20pm 8/13/13 1:20pm

These remarkable clouds look even more incredible from the ISS

Fifty miles overhead, higher than any other formation in our planet's atmosphere, is where you'll find one of the most enigmatic classes of cloud ever observed. They're called noctilucent clouds, and they're some of the most poorly understood meteorological phenomena on Earth. » 6/26/12 8:20am 6/26/12 8:20am