Incredible video of aurora from ISS

A true must-see:

NASA: “Video of the Aurora Australis taken by the crew of Expedition 29 on board the International Space Station. This sequence of shots was taken September 17, 2011 from 17:22:27 to 17:45:12 GMT, on an ascending pass from south of Madagascar to just north of Australia over the Indian Ocean.”

Dr. Jeff Masters: “The rippling green curtains of the aurora as the space station zooms overhead are amazing!”

SpaceWeather.com: “Note how the underbelly of the space station glows green from the reflected light of the auroras below. Also, in the distance, Sirius the dog star and Orion the Hunter can be seen rising feet-first into the night sky.”

In other orbital news, here’s the latest from NASA on the “UARS” satellite that’s tumbling toward an uncontrolled re-entry. It’s now expected to crash/splash down sometime tomorrow during the afternoon EDT, but it won’t hit North America. Where exactly it will hit remains uncertain. NASA says that, because Earth is still quite sparsely populated in the grand scheme of things (and most of its surface is water), there’s “only” a 1-in-3,200 of a piece of the satellite causing human casualties. (I’ve seen this misreported as “your chance” of being hit, but of course that’s wrong — the odds of any individual person being hit are 1-in-something-trillion.)

That said, if the satellite’s path during re-entry takes it over a populated area, the light show will be quite spectacular:

As the satellite descends to an altitude of about 50 miles (80 kilometers), friction with the atmosphere is converted to light and heat. As it moves on a relatively slow – one could almost use the adjective “majestic” – flight across the sky, what is usually seen is a long trail of light and sparks that can take on virtually every color of the rainbow.

Small chunks of the satellite may be seen to break off and trail behind the main body. (NASA expects up to 26 pieces from UARS to survive re-entry and reach the ground.) If the re-entry occurs at night, it could light up the sky with a brilliance that easily rivals the full moon. Even if it occurs during the daytime, the satellite’s fiery passage across the sky could be readily seen.

Notes veteran satellite watcher Kevin Fetter: “A nice sized [satellite] with a uncontrolled re-entry. What a nice light show it should put on, if the decay occurs where people can see it.”