Gary said:
"It would easy to establish one's credentials as a "green" by fighting for the ecology of another world through opposing Mars colonization."

I don't know anyone that opposes Mars colonization, I certainly do not, in fact if it was possible for me to go to Mars I would gladly go there.

"At the same time you'd get bonus points by standing up to "mindless progress", colonialism, the use of nuclear energy and the corporate greed of the aerospace industry (military industrial complex)."

I'm all for "mindFULL progress", in other words, colonization, the use of nuclear energy and the corporate greed of the aerospace industry (military industrial complex) should be composed of people that have a FULL mind of intelligence, so that they know (fully understand) the reasons for and the consequences of their actions.

"There are too many hot buttons here. The best case scenario would be for Mars to have billion year old fossils but currently be sterile."

As I implied before, let's look at ALL of the planet first before doing anything to it.
Who knows; if there is "life" on Mars, it may be possible for us to "live in perfect harmony" with them.

Johannes