Up to 30 fragments weighing a total of 1.87 tons could have crashed
Scientists not yet sure where research satellite entered atmosphere
Recalculated flight path suggests it could have crashed above Asia
But odds of any individual being struck are only one in 14 trillion
By Mark Duell
Last updated at 6:08 PM on 23rd October 2011
A German research satellite last night returned to earth at up to 280mph – but nobody knows where.
Scientists are trying to establish how and where the satellite landed on Saturday night, after warning that some parts might survive re-entry and crash at high speeds.
There is no immediate solid evidence to determine above which continent or country the ROSAT scientific research satellite entered the atmosphere, said the German Aerospace Center (GAC) said.
Most parts of the minivan-sized satellite were expected to burn up, but up to 30 fragments weighing a total of 1.87 tons could have crashed.
The German Aerospace Center said the satellite entered the atmosphere between 9:45 pm and 10:15pm Eastern Time on Saturday and would have taken only 10 or 15 minutes to hit the ground.
The agency said it could take days to determine exactly where pieces of the satellite had fallen, but that it has not received any reports that it had hit any populated areas.
‘I don’t think that we’ll have a confirmation of any sort today,’ the GAC spokesman said on Sunday, pointing out it also took NASA several days to establish where one of its satellites had hit last month.
Scientists said hours before the re-entry into the atmosphere that the satellite was not expected to hit over Europe, Africa or Australia.
According to a recalculated path it could have been above Asia, possibly China, at the time of its re-entry, but the spokesman said he could not confirm that.
The 2.69-ton satellite was launched in 1990 and retired in 1999 after researching black holes and neutron stars and performing the first all-sky survey of x-ray sources with an imaging telescope.
Fears subsided over NASA satellite
A dead NASA satellite fell into the southern Pacific Ocean last month, causing no damage, despite fears it would hit a populated area and cause damage or kill people.
Experts believe about two dozen metal pieces from the bus-sized satellite fell over a 500-mile span.
The largest single fragment that could hit into the earth is the telescope’s heat-resistant mirror.
During its mission, the satellite orbited about 370 miles above the Earth’s surface, but after its decommissioning it lost altitude, circling at a distance of only 205 miles above ground in June for example, the agency said.
Even in the last days, the satellite still circled the planet every 90 minutes, making it hard to predict where on Earth it would eventually come down.
The German space agency put the odds of somebody somewhere on Earth being hurt by its satellite at one in 2,000 – a slightly higher level of risk than was calculated for the NASA satellite (see box).
But any one individual’s odds of being struck were one in 14 trillion, given there are 7 billion people on the planet.