It seems the stuff of science fiction and Hollywood – satellites crashing to Earth – but rather this is the result of years of scientific and commercial ventures in outer space, and the subsequent creation of space junk.

NASA’s Upper Atmosphere Research Satellite (UARS) has fallen out of orbit and is falling towards the Earth. NASA has confirmed that UARS is expected to re-enter the Earth’s atmosphere on the afternoon of 23 September, Eastern Daylight Time. This re-entry will occur six years after UARS ended its productive scientific life when it ran out of fuel in 2005. In other words, UARS is now uncontrollable space junk.

Most of UARS is expected to break or burn up before reaching the Earth, but scientists have identified 26 separate pieces of the satellite that could survive the fall through the atmosphere, and NASA estimates that debris could therefore fall to Earth over an area 500 miles long. The largest piece of debris is expected to weigh over 150 kilograms.

NASA has stated that the debris could land anywhere between the latitudes of 57 degrees north and 57 degrees south – an area which covers the whole of Africa, South America, Australia and most of the populated parts of Europe, Asia and North America. (The northernmost boundary of this region passes through Scotland, Denmark, Sweden, Latvia, Russia, Alaska and Canada, and the southernmost boundary is just south of South America.) NASA is posting regular updates on its website but has said that its predictions will only become more accurate in the hours before the debris lands, and has so far confirmed that UARS will not be passing over North America at its expected time of re-entry.

NASA has calculated that there is a 1-in-3,200 risk to life from UARS, as debris could hit people, animals and/or buildings when it reaches the ground.

This note looks at some of the legal and policy issues arising out of this. Click here.

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