Comet lander Philae might run out of power soon

European Space Agency's comet lander Philae might run out of power soon as it rested in a cliff shadow and could not enjoy enough sunlight, said scientists in Darmstadt Germany on Friday.

Philae Lander Manger Stephan Ulamec confirmed in a press conference that the probe had activated a drill instrument onboard to take samples from a depth of some 20 centimeters underneath the comet surface.

The data could not be sent back to the earth currently as Philae's mother ship Rosetta, which served as a transmitting station for the lander, was under the horizon. The next contact window would open at 2100 GMT on Friday.

However, Philae's battery might be empty before the contacts resumption, he said.

ESA has confirmed that Philae bounced twice while landing on Comet 67P/Churyumov-Gerasimenko on Wednesday. The first leap lasted for nearly 2 hours and the lander was ultimately rested in a place, which was yet determined, 1 kilometers away from its planned landing site.

Scientists said pictures sent back by Philae after settling down showed that the lander sat in a shadow of a cliff. Its secondary battery, which would be the main power supplier after the main battery was used up, could not be charged sufficiently due to a lack of sunlight.

In current location, Philae's solar panels could only receive sunlight for 1.5 hours per 12.4 hour comet day, while in the original landing site, the illumination could be offered for nearly seven hours.

Ulamec said, once contacts were resumed with Philae, controllers on the earth would try to rotate the lander or to hop it out of the shadow.

Holger Sierks, a scientist oversees the OSIRIS camera onboard Rosetta, said Philae's touchdown and bounces might be observed by Rosetta, but the pictures were still waiting to be downloaded. Scientists would try to use these pictures to locate the lander.

Despite the uncertainties, Philae has conducted several experiments. Earlier on Friday, ESA said the lander had sent back data of properties on the surface and subsurface of the comet.