re: best hope for contact with Beagle2
How difficult would it be to image the area where the Beagle 2 is supposed to be? Two issues: resolution of existing cameras in orbit (future ones are going to be a lot better), and knowledge of where it was supposed to have come down.
A related question for electronics buffs: is there some passive device (requires no power) that when "pinged" by a powerful radio signal will emit a small signal of its own to allow it to be located? I know those little implantable chips do something like this at very short range. Sort of the non-directional radio equivalent of a radar reflector? If so, something like this could be included in future probes. Either an orbiting Mars satellite or some large Earth-based transmitter could do the "pinging."