Rosetta's lander Philae woke from hibernation after 211 days on the comet where it landed, the European Space Agency says.
The European Space Agency had received no signals from the Philae lander since November 2014.
Scientists at ESA said the lander communicated with its ground team for 85 second after waking from hibernation at approximately 10:28 P.M. on Saturday.
"Philae is doing very well: It has an operating temperature of -35ºC and has 24 watts available," project manager Stephan Ulamec said in a ESA statement. "The lander is ready for operations."
ESA said that while it had not received contact from Philae in the interim, data from the lander indicates that it woke up from hibernation prior. "We have also received historical data - so far, however, the lander had not been able to contact us earlier," Ulamec said.
The Philae lander announced the end of its hibernation with a Tweet.
Hello Earth! Can you hear me? #WakeUpPhilae
Last November, Philae landed next to a cliff that largely blocked sunlight from reaching its solar panels.
The historic landing climaxed a 10-year journey aboard the Rosetta space probe. Since alighting on the comet, some 311 million miles (500 million kilometers) distant from Earth, the lander has performed a series of tests and sent back reams of data, including photos.
Scientists hope the $1.6 billion (1.3 billion-euro) project will help answer questions about the origins of the universe and life on Earth.
One of the things they are most excited about is the possibility that the mission might help confirm that comets brought the building blocks of life — organic matter and water — to Earth. They already know that comets contain amino acids, a key component of cells. Finding the right kind of amino acids and water would be an important hint that life on Earth did come from space.
Scientists say they already have gathered huge amounts of data and are calling the first-ever comet landing a roaring success.
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