[Yossarian]

You'd be better to (...) enhance capabilities (i.e., being able to go where you couldn't otherwise go, like polar regions and/or canyons and deeper craters, where there may be evidence of water).

See my post #14 above for why mission planners want to keep a nuclear powered rover from going near water.

[chimera]

Read my post. I didn't say there was water (we don't know if there is or not) I said evidence of water (e.g., eroded formations, etc).

That said, keeping an RTG away from frozen sand (the most likely form) because of irrational antinuclear phobia is incredibly stupid. You probably don't know this, but plutonium-bearing RTGs have come down in the water, on this planet, and we all didn't die. The Apollo 13 lunar module carried an RTG that re-entered the atmosphere at trans-lunar velocity, survived reentry, and fell into the Pacific Ocean intact. I doubt if anything we send to Mars that will survive that trip has much chance of harming anything there, or here.