A defunct German research satellite has fallen out of orbit, and parts of it are believed to have reached the surface of the Earth, though their location is not known.
The Rosat satellite, a joint project between Germany, the UK and the US, has re-entered the atmopshere. Image credit: DLR
The Roentgen Satellite (Rosat) re-entered the atmosphere on Sunday between 2:45am and 3:15am after spending 21 years in space. Re-entry would have taken 15 minutes or less. Scientists are still trying to establish exactly where the debris, if any, landed.
"For us, it's not possible to say," Andreas Schuetz of the German Aerospace Center (DLR), told ZDNet UK. "We are waiting for [further] data in the next few days... from 12 agencies worldwide."
Rosat is a joint project run by Germany with UK and US involvement. It was the first satellite to survey space for X-ray sources to find hot, high-energy processes such as neutron stars and black holes. By the time the satellite was shut down in 1999, it had detected more than 80,000 sources of cosmic X-rays and its data had been used by more than 4,000 scientists from 24 countries.
The 2,426kg (2.6 ton) satellite re-entered the atmosphere at around 28,000kph. The DLR estimated that around 30 individual pieces weighing a total of 1.7 tons could survive re-entry and crash into Earth. The largest surviving fragment is expected to be the telescope's mirror.
Rosat could have come down over southeast Asia, on a course of re-entry that saw it descend over two highly populous Chinese cities, Chongqing and Chengdu, according to media reports quoting Jonathan McDowell of the Harvard-Smithsonian Centre for Astrophysics in Cambridge, Massachusetts.