Is finding life on Mars all that important? Nasa doesn’t seem to think so and it might have a point. We have now seen signs of flowing water on the Red Planet. The claims, first published in the journal Nature Geoscience, are based on interpretations of the light reflected on the planet’s surface. It’s a smart piece of detective work that has heightened enthusiasm for a quest to find life on Martian soil. Unfortunately for the excited, Nasa refuses to sanction such a mission.
Our obsession with the idea began in the 1970s. In the first half of the decade, space agencies launched 11 Mars missions, most of which were failures. The “curse of Mars” provided a mythology but no answers. Nasa successfully landed its two Viking probes on the planet in the mid-1970s. One of them even looked for life and found a suggestion of microbes living in the soil. The discovery was declared void, however, after an accompanying experiment failed to find carbon-based “organic” molecules. Without organics in the soil, it was thought, life couldn’t exist. The results must have been an error.
That second experiment has since been declared faulty. We have found organic matter on Mars. Some might argue that it is worth repeating the life-detection experiment but science has moved on. In the 1970s, “Is there life on Mars?” seemed like an epoch-defining question. Given that we now know that organic molecules have assembled into microbes in some of the most extreme environments on earth, it doesn’t seem unlikely that the same has happened on Mars. The planet does, after all, appear to have the materials and conditions that this needs.
It’s not even a stretch to imagine that simple, single-celled life is scattered through the galaxy. There is plausible evidence that life on earth was seeded by microbes ejected from the Martian surface as a result of a meteor shower. If this “panspermia” theory is right, we are all Martians.
Meanwhile, we would have to rule out contamination by the various spacecraft that we have sent up there if we want to claim that Mars is truly home to life. This would take a lot of effort for relatively little gain. Science has moved on.
These days, the intriguing issue is not whether there is life elsewhere but what it takes to make complex, multicellular life. In his book Lucky Planet, David Waltham, a geophysicist at Royal Holloway, University of London, argues that it requires a complex set of conditions that may have arisen only once in the observable universe – here, on earth. The biologist Nick Lane of University College London, the author of The Vital Question, has demonstrated that the transition from simple to complex life was almost certainly a fluke.
Doing geology and biological archaeology on Mars presents a fascinating technological challenge that will give us useful skills and experience – but it will tell us almost nothing about the validity of these more compelling ideas. It is a mistake to fixate on questions that are no longer pressing.
We have a new big question for the 21st century. Earth is populated by a vast array of multicellular organisms, some of which have evolved so far that they have intelligence and consciousness enough to contemplate their origins. How did this happen? Here’s a thought for governments ruminating on science budgets. Our best chance of a profound discovery is relatively cheap: well-trained, well-funded scientists working on basic science in well-equipped labs. It’s not rocket science.
This article appears in the 07 Oct 2015 issue of the New Statesman, Putin vs Isis