European science satellite disintegrates
Firey end A spent science satellite that had measured Earth's gravity field re-entered the atmosphere and mostly disintegrated as planned, according to the European Space Agency (ESA).
An estimated 25 per cent of the one-tonne GOCE satellite reached the Earth's surface over the southernmost regions of the South Atlantic ocean, it said, and "no damage to property has been reported".
Scientists had predicted that several dozen fragments of GOCE, totalling some 200 kilograms - about the weight of car engine - would survive contact with the atmosphere.
GOCE "is only a small fraction of the 100-150 tonnes of man-made space objects that re-enter Earth's atmosphere annually," said Heiner Klinkrad, head of ESA's space debris office in a statement.
"In the 56 years of spaceflight, some 15,000 tonnes of man-made space objects have reentered the atmosphere without causing a single human injury to date."
Falkland Islands resident Bill Chater saw GOCE blaze across the evening sky and captured it on camera.
"We saw it burn up from the Falklands at about 9.20pm last night. Came from the South breaking up into bits," he wrote on Twitter. An accompanying photo shows a trail of fire and smoke stretching across the sky.
He told BBC's Jonathan Amos: "Driving southwards at dusk, it appeared with bright smoke trail and split in 2 before splitting again into more and going on north."
The ESA later confirmed that the image was of GOCE re-entering the atmosphere.
Measuring gravity and sea levels
The Gravity Ocean Circulation Explorer (GOCE) satellite was placed in orbit in 2009 on a mission to monitor variations in gravity and sea levels.
The sleek, finned craft's mission came to a natural end when it ran out of fuel on October 21, leaving it without power to maintain its altitude in low orbit, where there are still lingering molecules of air.
GOCE was launched in March 2009 at an altitude of 260 kilometres - later lowered to 224 kilometres - the lowest ever for a research satellite.
The 350-million-euro ($AU500 million) mission has lasted twice as long as its initially-scheduled 20 months.
GOCE was designed and built before 2008, when international recommendations were adopted stating that a scientific satellite must be able to execute a controlled reentry, or burn up completely after its mission.