Midterm Essay – Searching for Life on Mars Is there other life in the universe? The answer to this question has eluded man since he began asking it. Whole philosophies and religions are based on the idea of the answer to that question being either yes or no. In the following we will be discussing a brief background of the habitability of Mars. Then we will discuss an outline of a mission to Mars to search for primitive life. First of all, a brief background of the habitability of Mars. Approximately 3.8 billions years ago, it is thought that Mars was a much warmer place, had a much dense atmosphere and possibly sustained liquid oceans. The probability of life existing in those conditions is much higher than they are today. Mars is now very cold, dry and has a thin atmosphere. This means that the only life which could exist today is primitive microbial life. So how can we find this life? To answer this question a detailed outline of a mission to Mars will be presented. What will we be looking for and where are we looking? Life, Mars. That is the short and sweet answer but it is much more complicated than that. When Mariner 4 flew past Mars it was only looking for evidence of water canals to support ideas of complex life existing on Mars. After returning a barren rocky landscape the notion of complex life was thrown out the window. Since then missions like Viking 1 and 2 have been conducted searching for microbial life. It returned only results which pointed to contamination from cleaning fluids. This at first was interpreted as the final nail in the coffin for finding life on Mars until it was discovered that the results were actual a product of reactions between perchlorates and organics in the soil. This does not mean that life is present just that organics are likely present in Martian soil. Viking and subsequent missions to Mars have taught us that it is possible for life to have existed and still might exist. We just need to look in the right places. Once place of interest is the polar regions of Mars where water is frozen on the surface. Drilling an ice core from these regions would reveal a lot about Mars past atmospheric conditions. Deep within these cores could be ancient life frozen, waiting to be discovered. Once the drilling is complete, sonar probes could be sent down the drilled cavity to map the subsurface terrain. Once a map is generated, large pockets of air or subsurface caves could be searched for. These subsurface caves would be excellent for searching for primitive life like that found in the Andean deserts or Antarctic glaciers. Another way to test to see if life could be sustained on Mars would be to take samples of the extremophiles found in the Andean deserts, Antarctic glaciers, underground caves and ocean vents to Mars. Once there they could be introduced to the Mars environment in a controlled manor and then tested to see if could still survive. While this is a good idea for testing to see if life could exist extra terrestrially it still would not mean that life had an origin on Mars, only that it can exist there. Another con of this experiment would be the obvious problem of forward contamination. Forward contamination is the process of bringing foreign life to another planet. This is a problem because forward contamination can have devastating effects on native life. An excellent example of this is the white man bringing disease to the Western hemisphere. To conclude I have given you a brief history of the habitability of Mars and how an earlier Mars could have been much more livable than today. You have also been presented an outline of a mission to Mars that would search for primitive life.