Night Shining Clouds
Noctilucent ("night-shining") Clouds over Bainbridge Island, WA tonight. Earth's highest clouds - 50 miles up, at the edge of space - they're visible from high latitudes for a few weeks around the summer solstice. They "shine" at night an hour or two after sunset (or before sunrise) because the sun is still hitting them at their altitude. Made of ice crystals believed to form around particles of meteor smoke.
