The Nasa Upper Atmosphere Research Satellite (Uars) could shower debris anywhere over the six inhabited continents - from as far north as Alaska to the bottom tip of South America.
Satellites as large as Uars re-enter Earth's atmosphere about once a year and Nasa said there have been no reports of any deaths or injuries to people from falling debris.
But space expert Doug Millard at London's Science Museum thinks this one is worth watching.
He said: "This is one of the largest satellites up there.
"It's about the size of a double-decker bus. Most satellites when they come down, they are smaller, they burn up and no one notices. Because of the size it's a little more significant."
Nasa has said the odds of a piece of the Uars debris striking a person is about one in 3,200.
The agency insists most of the 20-year-old probe will burn up in the atmosphere and that the debris will most likely fall into an ocean or land in an uninhabited region of Earth.
The probe is being tracked by radar stations and experts around the world. Read More