satelite hitting the uk
Mind your head: 1 in 3,200 chance that falling satellite could hit someone
Six years after ending its scientific mission, the Upper Atmosphere Research Satellite (UARS) is about to re-enter the planet's atmosphere and crash back down on home turf.
While the spacecraft will break into pieces and most of it will burn up in the blazing heat of the friction with the Earth's atmosphere, some large chunks will make it through and fall to the ground. They'll hit during late September or early October 2011, but it's too soon to know their geographic target -- they could land anywhere in the six inhabited continents.
"The risk to public safety or property is extremely small," American space agency Nasa writes, and says that there has "been no confirmed reports of an injury resulting from re-entering space objects" since the beginning of the Space Age. That being said, Nasa experts estimate a one-in-3,200 chance that a satellite part could hit someone.
Nasa now has rules and regulations to avoid putting people at such risk. The chance of any satellite hitting someone has to be one in 10,000 or less at all times -- but UARS was launched in 1991, long before this rule was put into place. The agency normally puts dead satellites into a " graveyard orbit" or steers them safely into the ocean, but there isn't enough fuel in UAR to shift it.
When the 550kg of metal does fall, it will have a debris footprint some 500 miles long. It shouldn't carry any hazardous material, but Nasa recommends avoiding touching any bits you might find and to contact local law enforcement for assistance.
UARS was deployed by the Discovery shuttle in September 1991 to study the Earth's atmosphere and its interaction with the Sun. As it tested for gases related to ozone depletion and climate change, Nasa says UARS provided conclusive evidence that human-produced chlorofluorocarbons (CFCs) led to the hole in the ozone layer. Whoops.
