Rosetta probe rests in the dark after epic space journey

After a bumpy landing, the deep-space probe Rosetta has achieved a stable foothold on the comet 67P/Churyumov-Gerasimenko, scientists from the European Space Agency (ESA) confirmed Thursday. But there are still some key unknowns regarding Rosetta’s status — including its exact position on the surface of the comet.

“We have a better understanding of how we got there,” said Head Rosetta Lander Stephan Ulamec during a press conference. “We still do not know exactly where.”

What is known is that the probe is relatively secure in its current position, though just two of its three feet are resting on the surface of the comet. Scientists with the ESA’s Rosetta project said they are proceeding cautiously, and will not activate the probe’s drill or its harpoons until they are sure doing so won’t destabilize the craft.

Rosetta and its 220-pound lander, known as Philae, reached the surface of the comet on Wednesday, following a decade-long, 4-billion-mile trek across the solar system. Rosetta is the first human-made object to successfully make contact with a comet, and scientists hope it will be able to study what happens to the celestial object as it moves closer to the sun.

However, the probe’s current position on the comet risks making the project slightly more complicated. Philae is outfitted with solar panels, but the ESA reports that the lander currently rests in the shadow of a cliff, limiting its ability to generate power. Philae presently has a little over 60 hours of battery life.

If the solar cells are not able to generate sufficient power to keep the batteries replenished, Ulamec said the probe can “go into a kind of hibernation mode.” It could then reactivate in several months when the sun hits the probe.

Mission scientist Jean-Pierre Bibring said the exact location of the Philae lander was difficult to calculate in part because it bounced twice while landing on the comet’s surface. At present, the lander is “not very close to the place we wanted, but not far away,” he said.