A bus-sized NASA satellite about to fall to Earth will be passing over Canada, Africa and Australia, as well as vast areas of the Pacific, Atlantic and Indian oceans, the space agency said Friday night.

Re-entry of the six-tonne Upper Atmosphere Research Satellite is expected between 11 p.m. ET Friday and 3 a.m ET Saturday, NASA said.

Earlier, NASA reported that the satellite had changed its orientation, throwing off earlier predictions about its descent and opening up the possibility that some debris will land in the U.S.

Part of it is expected to burn up in the atmosphere, but some metal chunks are expected to reach the ground.

Earlier in the week, the U.S. space agency had predicted the satellite would land Friday afternoon or evening and would miss North America.

5 movies about things falling from space

The End of the World (1916)

In this early Danish sci-fi film, a passing comet sets off natural disasters and social bedlam.

The Day the Sky Exploded (1958)

A malfunctioning rocket bashes into an asteroid belt and sends the cluster hurtling to Earth in this Italian doomsday feature.

Meteor (1979)

Sean Connery and Natalie Wood star in this nail-biter about a massive asteroid expected to make a violent landing on Earth.

The Night of the Comet (1984)

In this cult favourite, the passing of a comet unleashes a plague of zombies.

Armageddon (1998)

This Michael Bay feature stars Ben Affleck and Bruce Willis as a couple of oil drillers tasked with destroying a Texas-sized asteroid — by blowing it up from the inside.

The UARS satellite, launched in 1991 to take measurements of the ozone layer, has a mass of almost six tonnes and is a little over 10 metres long with a diameter of about 4.5 metres.

It was decommissioned in 2005 and other satellites have taken over the types of measurements it used to make.

NASA is warning the public not to touch possible satellite debris they find. The materials themselves are not hazardous, but people could be cut by the sharp metal edges.