Rosetta mission: Potential comet landing sites chosen

Europe's Rosetta mission, which aims to put a robot on Comet 67P/Churyumov-Gerasimenko, has identified five potential locations for the touchdown, the BBC reported. 

The choice of sites was driven largely by operational considerations - they are places engineers believe a lander can get down with the least risk.

No-one has attempted to land on a 10-billion-tonne comet before.

The Rosetta probe will despatch its Philae contact robot to 67P's icy surface on 11 November.

The European Space Agency says it will be a one-shot opportunity.

Rosetta and the comet are currently about 400 million km from Earth, making real-time radio control impossible.

Instead, the process will have to be fully automated with commands uploaded several days in advance.

The five sites on the "longlist" were selected at the end of a special meeting convened in Toulouse, France, this past weekend.

Esa project managers were joined by attendees from the space agencies of France (Cnes) and Germany (DLR), which play key roles in the Philae effort.

Instrument principal investigators on the washing machine-sized robot were also there to argue their preferences, as were the engineers, who could explain the technical possibilities.

If one considers the comet to look like a rubber duck, then three of the chosen potentials (B, I and J) are on the head. Two are on the body (A and C). The dramatic neck region has been ruled out.

The letter designation stems from an even longer list of 10 that was used to kick-off the whole selection process. The letter ordering carries no weight.

A landing site needs to be relatively flat and free from boulders and fissures.