(Updated: Saturday, 5:15 p.m. ET)

A defunct 6-ton NASA science satellite plummeted into the atmosphere early Saturday, showering debris most likely into the Pacific Ocean.

No injuries or damage from falling satellite debris had been reported on land, which NASA officials said was a good sign the satellite went into the ocean.

NASA believed its Upper Atmosphere Research Satellite, or UARS, returned to Earth sometime between 11:23 p.m. EDT Friday and 01:09 a.m. EDT Saturday. There were reports on Twitter of debris, presumably from UARS, over the skies of Okotoks, a small town south of Calgary, Alberta, Canada, but these later proved false.

NASA believes the satellite re-entered over the Pacific Ocean, although the exact location has yet to be identified — and may never be. 

"Because we don't know where the re-entry point actually was, we don't know where the debris field might be," said Nicholas Johnson, chief orbital debris scientist at NASA's Johnson Space Center in Houston. "We may never know."

If calculations were at all off, there was a chance some debris may have fallen over parts of northwestern North America.

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UARS had been slowly losing altitude since its mission ended in 2005. The spacecraft, nicknamed UARS, was dispatched by a space shuttle crew in 1991 to study ozone and other chemicals in the atmosphere.

NASA urges anyone who believes they may have found satellite debris to call police. While the debris would have no toxic contamination, the agency points out that It's government property and illegal to keep it or try to sell it.

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Image: The UARS satellite being deployed by the shuttle in 1991 (NASA)