BERLIN, Nov. 12 (Xinhua) -- Probe Philae successfully landed on Comet 67P/Churyumov-Gerasimenko, some 7 hours after being released from its mother ship Rosetta, confirmed European Space Operations Centre (ESOC) on Wednesday afternoon in Darmstadt, Germany.
Signals confirming the landing was received at 17:03 (1603 GMT), according to ESOC, about half an hour later than the actual touchdown as signals came from the comet which was 500 million kilometers from the earth.
Philae overcame a problem on its thruster system on board which was designed to push it onto the comet surface, and was anchored on the comet with the help of ice screws in its three legs and of two harpoons which were fired into the surface, according to Stephan Ulamec, Philae Lander Manager at the German Aerospace Center (DLR), a member of a consortium which led the European Space Agency mission.
"We are there, Philae is talking to us. He is sitting on the surface," said Ulamec in a webcast.
Philae made a history by landing, instead of colliding as NASA Deep Impact probe did in 2005, on a comet as the first human-made object.
It left its mother ship Rosetta at 9:35 (0835 GMT) and descended alone from a point 22.5 kilometers above the comet center.
The lander, via Rosetta which was escorting the comet, resumed contact with controllers on the earth two hours after the separation, and sent back scientific data and pictures.
"This is a big step for human civilization," said Jean-Jacques Dordain, Director General of the European Space Agency, in a press conference in Darmstadt after the landing confirmation.
Before landing, Philae had been flying with Rosetta for over 10 years and nearly 7 billion kilometers for chasing the Comet 67P/Churyumov-Gerasimenko.
Comets are the most primitive objects in Solar System. Scientists think that they have kept a record of the physical and chemical processes that occurred during the early period when planets were formed.
By studying Comet 67P/Churyumov-Gerasimenko's make-up with the help of the 10 scientific instruments onboard Philae, scientists wish to unlock the secret of solar system and even the origin of human lives.
Earlier, a variety of molecules, including water, carbon monoxide, carbon dioxide, methane, and a few nitrogen or sulphur species have been detected by scientific instruments on Rosetta.
Experiments would start after the Philae's landing, and last until March 2015, when the comet would be too close to the sun and the surface temperature would be too high for Philae to operate.
Rosetta, meanwhile, would continue to escort the comet and watch its evolution as it orbits the Sun.
(Source: CNTV.cn)
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