Responding to dtb's comments:

>I don't know that I buy the hardcore version of the White Mars theories
>that the role of liquid water was negligible and CO2 carved everything,
>but even with the new models where things are basically frozen but you
>get very brief periods of impact-generated rainfall are not at all warm
>or wet -- not very life friendly at all. That's what this non-specialist
>takes away at least, though I guess we can't rule out the possibility
>that I've simply been tricked by Nick's superior persuasive ability.

The big of virtue of Nick's theories is it forces us to think outside of
the box. Before scientists like Nick got involved, the mindset was:
"Of course Mars was Warm and Wet, that's a proven theory!" People were
designing missions assuming that Mars was warm and wet. Look at Beagle-2.
It's mission was to search for life ***On or near the martian surface***.
It amazing how stupid people can be. Nick may not have all the right
answers but at least he's forcing us to ask intelligent questions.

>The implication is that finding fossils won't be easy. At best, sounds
>like we need to send a bunch of rovers to turn over a whole lot of rocks.
>That gets expensive and demoralizing. Nope, not there. Nope, not there
>either.

IMHO, there is only one practical way to search for fossilized life on
Mars: First colonize the planet. There's plenty of ice on Mars and people
will need lots of water. Therefore keeping the colony alive will require
considerable strip mining. Have a standing order with the mine geologists
to keep their eyes open for fossils. Make part of a Martian undergraduate's
training in geology to comb through mine tailings and look for interesting
clues. Maybe after one or two centuries of casual searching, someone might
get lucky and find some localized pocket of fossils. It's unlikely that we're going to find any fossils by landing spacecraft willy-nilly on Mars and controlling
them remotely like MER.

>So if our program is centered around "finding life", what do we do when
>that seems unlikely, or at best an expensive crapshoot? We stay home,
>that's what.
>
>The real question is, could we generate enough support for a Mars program
>without life being so central?

No. Basing Mars exploration on exobiology was a serious blunder and
doomed to failure. First rate scientists like James Lovelock and Lynn
Margulis predicted that Mars was dead before Viking. Their original
insight should have been respected and even more so after Viking
vindicated their opinions. Again, exploring Mars is like playing
Twenty Questions. We can't play this game by simply asking: "Is it
George Washington? No. Is it Warren G. Harding? No. Is it Millard
T. Fillmore? No....." We need to ask: Is olivine abundant on the
martian surface? Is Mars geologically active today? Were the martian
"riverbeds' created by pyroclastic flows? The tactic of maintaining
public support by presupposing that Mars has or had biology is idiotic. That
strategy guarantees a very pissed off public after the planet is found
to be dead. We should be selling Mars on the promise that the world has
colonization potential. Mars can not be colonized over night. It would
take at least 10 years to simply get the spacecraft heat shields correctly
designed (that's what I do for living). Add another 30 years to get basic
technologies like steel smelting and glass production down pat. The
future industrialization and colonization of Mars should be the driving
theme behind Mars exploration.

Gary