BERLIN - A comet-chasing space probe that has been in hibernation for almost three years has woken up and sent its first signal back to Earth.
The European Space Agency received the all-clear message "Hello World!" from its Rosetta spacecraft some 800 million kilometers (500 million miles) away shortly after 10 a.m.
Rosetta was put into hibernation in 2011 to conserve energy for its long journey to meet with comet 67P/Churyumov-Gerasimenko.
If all goes as planned the probe will rendezvous with the comet in the coming months and drop a lander onto its icy surface in November.