Nasa searches for satellite debris
Washington - Nasa officials scrambled on Saturday to locate any remains of a bus-sized satellite - the biggest piece of US space junk to plummet to earth in 30 years - that disintegrated upon on re-entry into the Earth's atmosphere.
Nasa has said there is only a "very remote" risk to the public from any of the fragments of the 6.3-ton Upper Atmosphere Research Satellite (UARS) that may have survived the journey back into the atmosphere.
The satellite fell back to Earth between 23:23 on Friday and 01:09 on Saturday (03:23-05:09 GMT on Saturday), but the precise re-entry time and location "are not yet known with certainty", Nasa said.
The tumbling motion of the satellite has made it difficult to narrow down where it landed, with the ocean considered likely and the exact number of pieces of debris it broke into is still unknown.
The Joint Space Operations Centre at Vandenberg Air Force Base in California said the satellite penetrated the atmosphere over the Pacific Ocean, but the landing site was still not confirmed.
The 26 satellite fragments that Nasa earlier said may survive re-entry could weigh anything up to 1 158kg. Nasa said the debris field could span 800km.
Canada, Africa and Australia had all been named as possible sites for touchdown of satellite debris.
On its Twitter feed, Nasa said, "We're standing by for UARS location updates from the US Joint Space Operations Centre. No reports of any damage or injury."