12:46pm

Fri September 23, 2011
The Two-Way

Falling Satellite's Return Delayed, U.S. Again A Possible Landing Site

NASA has updated its news on the pending descent of the Upper Atmosphere Research Satellite, and here's the headline: the satellite's re-entry has been pushed back. The UARS is now expected to plunge towards Earth late today or early Saturday, EDT.

The main drag on the satellite's speed - solar activity - is no longer the main reason why the spacecraft is slowing down. Its path, speed and spin are now so unpredictable that scientists say they cannot estimate when it will fall.

The video above was taken last week by French photographer Thierry Legault - you can see the UARS tumbling in orbit. Legault suspects the satellite was struck previously by space debris, making it very hard for researchers to determine where and how it will return to Earth. The question is - where?

NASA has even put parts of North America back on the possible UARS crash site list. "There is a low probability any debris that survives re-entry will land in the United States, but the possibility cannot be discounted because of this changing rate of descent." Yesterday, NASA said North America was off the landing list because the satellite wouldn't be in orbit above it.

NASA's risk assessment suggests a little more than two dozen metal fragments may reach the planet's surface, and some could be heavy and large. If you want to track it yourself with your Android, check out the app here, or for more fun, visit spaceweather.com and plug in your zipcode. You'll find even more satellites that are orbiting over your head.

Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.