Berlin, Oct 23: A bus-sized defunct German satellite plunged to Earth today after languishing in a dead orbit for more than a decade, but space officials are not sure if any of its debris has hit the planet.
 The 2.7-tonne Roentgen Satellite, or ROSAT, slammed into Earth's atmosphere sometime between 01:45 GMT (6:15 IST) and 02:15 GMT (6:45 IST) on Sunday, but there is no information if its debris fell on the planet, the German Aerospace Centre (DLR) said in a statement.
 “There is currently no confirmation if pieces of debris have reached Earth's surface," the statement said.
 However, DLR spokesman Andreas Schuetz said they would have to "wait for data in the next days" to know when and where the debris fell or could fall.
 Scientists were no longer able to communicate with the dead satellite and it must have travelled some 20,000 km in the final 30 minutes before entering the atmosphere, he added.
 While the 21-year-old satellite broke apart as it entered Earth's atmosphere, DLR officials estimated that up to 30 pieces, weighing 1.9 tonnes, consisting some of heat-resistant mirrors and ceramic parts, could survive the fiery trip and reach the surface of the planet.
 Based on ROSAT's orbital path, these fragments could be scattered along a swath of the planet about 80 km wide, they had said, adding that there is, however, roughly one-in-2,000 chance of hitting someone on Earth, SPACE.Com reported.
 The satellite, which weighs 2,426 kg, was launched into orbit in 1990 to study X-ray radiation from stars, comets, supernovas, nebulas and black holes, among other things.
 It was originally designed for an 18-month mission, but it far outlived its projected lifespan. In 1998, its star tracker failed, forcing its X-ray sensors to pointed directly at the sun. This caused irreparable damage to the satellite, and it was decommissioned in February 1999.

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