Falling NASA Satellite Could Spark Stunning Light Show

A NASA satellite the size of a school bus is just days away from taking a fiery plunge into Earth’s atmosphere and could set off a dazzling display when it does … if anyone is able to see it.
NASA's 6 ½-ton Upper Atmosphere Research Satellite is due to fall somewhere on Earth Friday (Sept. 23), though exactly where and when remains a mystery.

If you happened to be lucky enough to be within viewing range of a satellite that is re-entering the atmosphere, the sight, put simply, would amount to a short-lived but spectacular fireworks display. Unlike a fireball meteor, whose flight across the sky might take no more than a few seconds, a re-entering satellite’s path usually lasts much longer.
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. [Photos of NASA's Huge Falling Satellite UARS]
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."
http://www.space.com/13036-nasa-satellite-falling-earth-skywatching-light-show.html