Reposted from @nasa A postcard from the edge of space.
These electric-blue clouds are only visible when the Sun is below the Earth's horizon and illuminates them.
Pictured from 269 miles above the South Pacific on an orbiting International Space Station, noctilucent clouds, or night shining clouds, are the highest clouds in the Earth's atmosphere.
Image Credit: NASA
#NASA#Space#clouds#horizon#spacestation - #regrann