1:01pm

Mon January 20, 2014
The Two-Way

Rosetta Space Probe Gets Interplanetary Wake-Up Call

... That's the message received from a bleary-eyed comet-chasing space probe on Monday, much to the relief of ground-based controllers who sent it a long distance wake-up call after nearly a three-year nap.

The European Space Agency received the communique from deep space on schedule at 1 p.m. ET from Rosetta, some 500 million miles away on a trajectory to rendezvous with comet 67P/Churyumov-Gerasimenko in August. It's been in sleep mode to conserve power.

As we reported last month, Rosetta was launched in March 2004:

"The 6,600-pound spacecraft, which has spent nearly a decade making repeated flybys of Earth and Mars to gain enough speed to catch the comet, was put in hibernation in July 2011, after its last major gravity-assist maneuver. ...

"In August, Rosetta will pull up alongside and on Nov. 11, 2014, is set to place its robotic lander, called Philae (after an island in the Nile River) on the comet's surface."

The Associated Press says:

"Scientists hope the probe's findings will help them understand the composition of comets and thereby discover more about the origins and evolution of our solar system.

"Comets are regarded as flying time capsules because they are essentially unchanged for 4.6 billion years. Scientists have speculated that comets — which are essentially giant, dirty snowballs — may be responsible for the water found on some planets. And like asteroids, comets also pose a theoretical threat to life on Earth."

Copyright 2014 NPR. To see more, visit http://www.npr.org/.