BERLIN (AP) -- 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 7 p.m. (1800 GMT; 1 p.m. EST).
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.