This coming Friday, be sure watch the skies if you're headed out – NASA are predicting that one of their inoperative satellites will be heading back to earth at speed in a shower of debris.

The broken Upper Atmosphere Research Satellite (UARS) is around the size of a bus and was first sent into space in 1991.

NASA has said that the debris, which should mostly be burned up on re-entry and will most likely fall into the sea or onto unoccupied land. However, the chance that it will hit a person is about one in 3,200 – the odds of being struck by lightning in the average lifetime are 5000 to 1.

"It is too early to say exactly…what geographic area may be affected," NASA's offical site states.

The satellite was in operation for 14 year collecting ozone chemicals from the atmosphere, and since it completed its mission in 2005 has been on a gradual downward fall.

NASA warn on their website, "If you find something you think may be a piece of UARS, do not touch it. Contact a local law enforcement official for assistance."