Astronomy Picture of the Day

Explanation: What do auroras look like from above? Behold! From the ground, auroras dance high above clouds, frequently causing spectacular displays. From space, they look a bit different. As the International Space Station (ISS) circles the Earth every 90 minutes, it sometimes sees auroras below that are active on the night side. A one-hour time-lapse video showing auroras from above was captured about two weeks ago from the orbiting ISS. The ISS -- and all objects in low Earth orbit -- will pass well above green auroras but just a bit above red glowing auroras. The aurora's electron and proton streams are too thin to be a danger to the ISS, just as clouds pose little danger to airplanes. From orbit, as magnetic fields change, auroras can appear to squiggle and crawl like giant snakes. The one-minute video featured was captured by French astronaut Sophie Adenot of the ISS Expedition 74 crew.