Heads up! Despite earlier forecasts that it would probably miss North America, experts are now saying that dead satellite that is returning to the earth's atmosphere could come down over North America, possibly the US, tonight or saturday.

NASA officials now say the UARS or Upper Atmosphere Research Satellite is slowing it's rate of speed and the trajectory continues to drop as it slows down.   This is making projections for where it will re-enter our atmosphere more difficult.  Each time it slows even slightly, that results in changes that could move it's re-entry by hundreds of miles.  Based upon what is known about heat and friction from re-entry, NASA officials expect the bird to break into 20-26 pieces, the biggest of which would be about 300 lbs. The bus-sized satellite was launched by NASA in 1991 to study the upper atmospheric conditions, it was decomissioned, or shut down, in 2005.  This is the largest satellite to fall "uncontrolled" from space since 1979.  So, keep an eye out for what NASA officialss call spectacular fireworks looking lights in the sky...if it's close to where we live, we will know it.