Rise and shine, Philae

THE Rosetta mission’s hibernating lander could awake within weeks, according to new predictions that it will soon be receiving enough sunlight to recharge its batteries.

The Philae probe shut down just three days after making a spectacular but bumpy landing on the duck-shaped comet, 67P/ Churyumov-Gerasimenko, and has been in a dormant state ever since.

Despite making it to within 800m of its target on the comet’s “head”, after a 400 million kilometre journey through space, the lander came to rest in the shadow of a cliff – so its solar-powered batteries have been unable to recharge since November.

As the comet approaches the Sun, the lander will be experiencing more intense sunlight and could enter its rebooting routine within weeks.

Stephan Ulamec, the lander manager, said: “What we’ve learnt is that the power will probably be sufficient ... The lander may be able to boot in April or May.“

Philae needs to be able to harvest enough energy from its solar panels to reboot and re-establish communication with its mothership Rosetta, which is around 200km away.

The Rosetta team predicts that communications could be re-established by May or June and that by July and September, Philae is likely to be getting enough energy to recharge its batteries, allowing it to continue operations at “night-time”, when it is not in direct sunlight.

Ultimately, it may be possible to re-operate the lander’s drill and collect more surface samples, which would be baked in a small onboard oven to analyse the gases given off.

When deployed in November, Philae rebounded twice from the comet’s surface before coming to a final standstill – allowing data to be collected from several points on the surface.

Analysis of these results shows that, contrary to prior expectations, the comet does not have its own magnetic field.

The discovery challenges one of the leading theories on how comets and the precursors of planets first began to form in the infant Solar System.

Andrew Coates, head of planetary science at UCL’s Mullard Space Science Laboratory, said: “The problem with solar system formation has always been what gets it going in the first place.“

According to Ulamec: “One leading theory has to be deleted from the textbook now.“

The findings suggest that swarms of particles may have simply stuck together when they happened to bump into each other, eventually snowballing into masses big enough to have sufficient gravity to accumulate further material. — Guardian News & Media