Looks like JPL is gearing up for a big announcement next week on results from Spirit and Opportunity.
The discovery of water in the soil wouldn’t be all that surprising, since we already know there is plenty of water on Mars (the novelty would be in its ubiquity, specifically in low latitudes where the conventional wisdom says it shouldn’t exist in near-surface soil). Such an announcement, while certainly a scientific coup, wouldn’t have much impact on space exploration. The public won’t rush to spend tens of billions of dollars in a crash program to send humans to Mars by the end of the decade, for example, just because water is found in surface soils.
If the announcement is life-related, however, who knows? The spherules, filaments, and rotini have raised the life question, but can we be certain it is life from just the imagery (assuming it doesn’t move, change shape, procreate, create expressionist sculptures, perform a tensor calculus solution, etc., between frames)? At the least, it would mean greater public support for spending money on robotic exploration — bigger, more sophisticated, and more numerous rovers, for example, to return to these sites and perform conclusive tests for life. Less likely, but still possible, is that it could generate increased public support for sending humans to Mars, either on the Moon-Mars timeline or even on an accelerated schedule (skipping all but the shakedown activities on the Moon, for instance).
Unfortunately, I suspect that if indications of life are announced, it will mean the quarantine of Mars, for the long term. Rather than risk further forward contamination, future landers would likely be terminated (aside from maybe an additional lander sent to confirm that life is indeed present). Future orbiters might be terminated as well, to prevent any contaminated spacecraft from inadvertently reaching the surface. Manned missions would be out of the question, not only because we humans are walking microbial menageries ourselves and would of necessity bring Earthlife to Mars with us, but also because of the unknown “risk” of backward contamination via the returning astronauts.
It would be interesting to find life on Mars, but it would be something of a mixed blessing if as a result of such a discovery we lost the only other planet in the solar system that we could settle in the near term.
UPDATE: Apparently it wasn’t clear, but the “quarantine” scenario was intended as a lament about what could happen, not what would automatically follow from a discovery of signs of life on Mars.