Bus falling from sky Thursday or Friday

“Satelite expected to hit Earth Friday - or Thursday

Atlanta Business Chronicle by Carla Caldwell , Morning Call Editor

Date: Monday, September 19, 2011, 5:58am EDT

Scientists say a 12,500-pound NASA satellite the size of a school bus is tumbling toward earth and will crash to the surface Friday. Or, perhaps, Thursday. Maybe Saturday, reports the Washington Post. Crashing satellites aren’t easy to predict, even for the detail-oriented folks at NASA, the newspaper points out.

NASA’s projected crash zone for the 35-foot-long Upper Atmosphere Research Satellite, or UARS — YOU-arz — is somewhere between 57 degrees north latitude and 57 degrees south latitude — which covers most of the planet, and particularly the inhabited parts, the WP says.

The difficulty in pinpointing the satellite’s path is partly due to the difficulty in projecting what solar activity will occur. That activity affects the drag on the vehicle, according to a NASA scientist.

The odds of any one person in the world (the population is about 7 billion) being struck by debris is about 1-in-3,200, according to NASA’s calculations, the newspaper reports.

The satellite is the largest piece of space junk to fall to Earth in 30 years, according to NASA, the WP reports. NASA’s calculations have the satellite partially burning up as it re-enters the Earth’s atmosphere and breaking into about 100 parts, creating balls of fires that should be visible even during the day.

Scientists said they expect to have a better fix on where debris will land closer to Friday.

Click here to see a graphic of the satellite.”