Scientists urge Philae team to 'hang the risk' as preparation for comet drilling begins

Drilling to search for organic compounds could unlock the mysteries of the origin of life on Earth - but it could also spell an end to Philae's mision

Rosetta's lander Philae is safely on the surface of Comet 67P/Churyumov-Gerasimenko (EPA)

The Philae lander has begun drilling operations on comet 67P despite scientists’ fears that using the equipment could dislodge the probe.

After Philae’s harpoons failed to secure it to the surface of the comet during its landing Thursday the craft bounced a kilometre wide of its intended landing spot and is currently resting on its side at the foot of a cliff with slowly depleting power.

The incredibly weak gravity on the comet (several hundred thousand times weaker than that on Earth) means that any physical movement from Philae could tip it onto its back or even launch it into space.

However, as scientists have now exhausted all safe experiments possible, instructions to activate the drill have been uploaded to the craft with a collective decision to “hang the possible risk,” in the words of University of Oxford professor Christ Lintott.

Lintott tweeted that the decision was “edge of the seat science” with the ESA team also considering the possibility of 'bouncing' Philae into a new, more favourable position tomorrow using its landing equipment.

Scientists are still not sure of the lander's exact location. It initally touched down in the correct spot (bottom left) but then pinged over to a shady clif (top right).

Although the probe has already retrieved valuable data from its other on-board instruments (scientist say bout 80 to 90 per cent of what was planned), the drilling experiment is still the centrepiece of its work: searching for organic compounds in the sub-surface ice could answer many important questions about our Universe, including perhaps the origin of life on Earth.

However, even if the drilling is successful, Philae's shady position at the foot of a cliff means that the long-term viability of the project is in doubt. The lander is only receiving one and a half hours' of sunlight compared to the six or seven hours that were planned for and its internal batteries are running out.

“We are coming now to the end so we are taking more and more risks,” head of mission operations Paolo Ferri told ScienceMag.

Even if Philae powers down in the next day scientists say there's a chance it could be revived as 67P speeds closer to the Sun and shadows shift, hopefully putting the lander's solar panels back into the open.

During a press conference at 13.00 GMT today, ESA scientist also confirmed that due to the orbit of Rosetta they'd not be able to contact the lander until 23.00 GMT tonight - when more information about the success of the drilling operation will be available.