"A defunct NASA satellite the size of a bus that is expected to fall to Earth on Friday will likely miss North America, NASA said.
The agency's 13,000-pound (5,900 kg) Upper Atmosphere Research Satellite, or UARS, has been slowly tumbling from orbit since its mission ended in 2005. It is expected to re-enter Earth's atmosphere and break apart on Friday."
The UARS satellite played a historic role in investigating the atmospheric chemistry behind the stratospheric ozone hole, and has been replaced by more advanced instruments gathering additional data.