It took four hours and 26 minutes for the signal to travel more than 2.9 billion miles (4.7 billion km) back to Earth to confirm that the probe was alive. It was picked up by NASA’s Deep Space Network station in Canberra, Australia. 

After a nine year voyage, this is the farthest any space mission has traveled to reach its primary target.

Operators at the Johns Hopkins University Applied Physics Laboratory confirmed at 9:53 p.m. (EST) ) 02:53 (UTC) that New Horizons, had switched from hibernation to active mode, as its pre-programmed computer commands instructed.

Launched on January 19, 2006, New Horizons has spent about two-thirds of its flight time, 1,873 days, in hibernation.

During hibernation mode, much of the New Horizons spacecraft was unpowered. The onboard flight computer monitored system health and broadcast a weekly beacon-status tone back to Earth. 

As part of the wake-up, NASA broadcast a special version of Where My Heart Will Take Me, by English tenor Russell Watson, which included a greeting to New Horizons from the singer.

The next few weeks will be used to check that the spacecraft's systems and science instruments are operating properly, and to build and test the computer-command sequences that will guide New Horizons through its flight to and reconnaissance of the Pluto system. 

“New Horizons is on a journey to a new class of planets we’ve never seen, in a place we’ve never been before,” said New Horizons Project Scientist Hal Weaver, of APL. “For decades we thought Pluto was this odd little body on the planetary outskirts; now we know it’s really a gateway to an entire region of new worlds in the Kuiper Belt, and New Horizons is going to provide the first close-up look at them.”