One of the best arguments for making the trip is pragmatic. We are now embarked as a civilization on a program of sustained global environmental management; we have changed the climate already, and from now on we have to deal with the Earth as a total dynamic system, trying to keep it all in balance. The better we understand our planet, the better we will be able to keep it (and ourselves) healthy. One of the most powerful scientific methods for understanding something is to compare it with other things like it, and there aren’t many options when you look around for other planets to compare with Earth. For the foreseeable future, Mars is not only the best choice, it is probably the only one. We’ve come to understand that the two planets shared very similar beginnings, then radically diverged; understanding more about the two planetary histories will teach us a lot about Earth. So we should go to Mars to help us here. It’s as simple as that. Comparative planetology is an environmentalist tool, and going to the Red Planet is a green project.
The second reason is more abstract, but so fundamental to our grasp of who we are that it can’t be easily dismissed: we should go to Mars to search for life there. This is a new idea; after the Viking landings in 1976 it was assumed that Mars was lifeless. But since then we have discovered life on Earth in such unlikely harsh environments that a new word, “extremophiles,” has been coined to describe these hardy microbes. It appears now that life can exist anywhere there is water and some minerals. Mars may have these ingredients in abundance, far under its frozen surface. Scientists have already claimed to have found fossil bacteria in the Martian meteorite ALH84001, and while this particular finding is contested, the possibility that life once existed on Mars is generally acknowledged, as is the possibility that it is still there deep underground. If we go there and find life, or even fossil evidence of past life, it would be one of the most important scientific discoveries in history.
Some will say we can send robots to make these investigations. Robots like Pathfinder and the Polar Lander will land on Mars biannually for the coming decade, and they will send back valuable information. But the search for life will be difficult to do mechanically, and the truth is that humans are much better at field geology than robots. A single human expedition would teach us more than a century of robotic landings, as members of the team lived there for six months or a year, wandering over the astounding red landscape performing one complicated experiment after another; their work and problems would be more interesting than the robots’ as well.
This last is no trivial matter. We live for our stories, and it would be inspiring to see our civilization make a peaceful inter-national effort to explore another world, seeking knowledge rather than profits. So we should enjoy the fruits of the robot missions, while at the same time deciding to go ourselves, and designing the robotic missions to set the groundwork for our arrival.
The case for going in person is also strengthened by the fact that it looks much less expensive than it used to. A study during the Bush administration put the cost at $450 billion. Tighter engineering has recently revised that downward tenfold, to $50 billion spread over a decade. This is back within the realm of the thinkable, even within the realm of NASA’s extremely modest budget. Costs fairly low, benefits extremely high; challenging both technically and socially; educational, exciting, inspirational, appealing to all that is best in human nature; really, the strange thing would be to neglect to go. Let’s go!
