Speculation about life on Mars has been rampant this fall. Rumors that the Mars Curiosity Rover may have found evidence of life on Mars have surfaced twice in the past few weeks. The most recent rumor started when a member of the Curiosity team was quoted as saying that they had collected data that was "Earthshaking" and "one for the history books." This led to a barrage of rumors that Curiosity may have found organic material on Mars and some people even speculated that life had been found. The reality gave no confirmation of life, but the NASA press conference on December 3, 2012 did reveal that some simple organics were found. They were not sure if they were indigenous to Mars, if they may have been residual organics from Earth, or if they had been deposited from other space objects (meteorites) impacting Mars.
Curiosity's mission should give us the answer to this eventually as it is scheduled to continue for at least another 18 months and was recently "officially" extended indefinitely. This gives Curiosity ample time to sample soil and rocks in some highly promising locations within Gale Crater on Mars. If organics exist there, Curiosity should know within the next few months.
Although Curiosity is not designed to verify life, we are left to wonder -- if Curiosity did discover life on Mars, what would be the impact of that discovery to the general public and to the future of human and robotic exploration of Mars?
One thing is certain, it would have a substantial impact, but the nature of that impact could move in many different directions. A popular belief is that if we found life on Mars this would accelerate our goals of sending humans to Mars as well as our robotic efforts, and also might transform our religious and societal beliefs. This isn't necessarily the case.
Our Place in the Universe
In fact, we have already had a test run for this hypothesis. Back in 1996, scientists announced findings that indicated that they had found fossil evidence of microbial life forms on a Martian meteorite (ALH 84001) that had been found in Antarctica a decade earlier. The story became a media sensation and President Clinton conducted a press conference to discuss the discovery. The announcement certainly did impact our robotic missions planning, but it did little to advance human space flight (we didn't change directions in human space flight until after the Space Shuttle Columbia disintegrated in the skies over Texas.) The public enthusiasm to the announcement was also very short lived and there is little evidence that it transformed anyone's religious or societal viewpoint. Would the confirmation of current microbial life be different? Probably not. The public would be engaged for a while (and probably enthusiastically), but the enthusiasm would be relatively short lived. It would likely take the discovery of a higher life form to ignite the type of passionate debate and emotion that was seen in the movie Contact.
Save the Microbes!
Perhaps the greatest impact would be within the mission planning community and among policy makers. Life on Mars will almost certainly make human missions to Mars far more complicated to plan. Planetary protection protocols would be very strict as we planned human missions to Mars. We would have to assure that there would be no forward, nor backward, contamination. This would become a VERY serious issue.
We should expect potential lawsuits from "Mars environmentalists" trying to block ANY human missions to Mars, claiming that we threaten the existence of indigenous Martian life. We would almost certainly hear protestors yelling slogans like "We've ruined our own planet, what right do we have to ruin Mars." This process would probably be similar to the reaction in advance of the launch of the Cassini mission to Saturn back in 1997. This mission was carrying 72 pounds of plutonium dioxide (not the more dangerous plutonium 239 used in nuclear weapons) to power the mission.
The mere fact that there was a form of plutonium on board sparked fears that if the rocket exploded, plutonium would rain down on central Florida. There were numerous protests outside NASA and there even was a legal challenge in the Federal Court of Hawaii challenging the mission's Environmental Impact Statement. Only after this challenge was rejected in Hawaii and in the Ninth Circuit Court of Appeals was the mission able to launch. Like Cassini, the legal challenges to a Mars mission would be likely to fail. Depending on when the discovery of life was made (is a human mission ten years in the future or one year in the future from the discovery), it could slow down a human mission to Mars. Discovery of life might also serve as a catalyst for various nations to propose contamination protocols in the United Nations - protocols that the US would probably not sign. Again, this would not be enough to stop a human mission to Mars.
That said, the discovery of even microbial life on Mars will be one of the most significant events in human history. And when we do send humans to Mars, we will absolutely need to take precautions and make sure we have solid protocols in place to protect Martian life and protect the crew and Earth from Martian life.
The Human Factor
Still, discovery of life on Mars should not stop a human mission to the Red Planet. On the contrary, it should be a strong case in favor of such a mission. After all, it will be far easier for us to understand the nature of this interplanetary strain of life if we have human scientists there to analyze it. There is also the strong possibility that we will not be able to provide 100 percent verification of Martian life until we send humans to Mars. At least for the foreseeable future, human explorers are the most accurate and efficient method of not only determining the nature of Martian life, but also determining long-term protocols for the protection of both indigenous life forms on other planets and for humanity.
Let's hope that if such a discovery is made in the next few years, we are able to proceed in as rationale and productive a manner as possible.