Whilst the majority of the bus sized Upper Atmosphere Research Satellite (UARS) will burn up upon re-entry into our atmosphere, NASA has indicated that about 26 parts will survive the intense heat and will fall to Earth: including 4 titanium fuel tanks, 3 batteries, 4 steel flywheel rims and an aluminium structure that on its own will weigh 158kg.
Although NASA is tracking the orbit of the falling satellite, the final destination of these objects won’t be known until minutes beforehand due to continuous changes in the atmosphere caused by the Sun.
Target zone is anywhere between 57 degrees latitude north and 57 degrees latitude south, i.e if you live further north than Quebec or further south than Argentina you should not be at risk.
Though you may cast an occasional look to the skies over the next day, I wouldn’t worry too much as you would have to be incredibly unlucky to be struck by some of the falling debris. NASA calculates that there is a 1 in 3,200 chance that a piece will hit a person somewhere on the planet, whilst you own personal risk of you specifically being struck is 1 in 21 trillion – you are far more likely to win this week’s lottery!