VOLCANO

Their research shows that hydrocarbons, the basic building blocks of life, can form during the cooling process from the hydrogen and carbon monoxide present in the gases. The optimum time for this to happen, the calculations showed, was when the volcanic gases which spewed from the Earth at a temperature of about 1200 degrees C cooled down to between 150-300 degrees C. The researchers have taken the work a step further by suggesting that conditions which are favorable for hydrocarbon synthesis may also favour the formation of amino acids, and ultimately, self-replicating molecules. The work implies that life could arise even today from the gaseous crucible of earth's present day terrestrial volcanoes. The work also shows how life may have arisen billions of years ago on early Earth, Mars and Jupiter's satellite, Europa. Co-author Dr Everett Shock who is professor of earth and planetary sciences in Arts and Sciences at Washington University, said the calculations prove what can happen thermodynamically, but not necessarily what will happen. "Developing them is an important first step in understanding this process. For the first time, we now have a quantified temperature zone in which hydrocarbons can form, and a framework to understand what conditions lead to hydrocarbon formation from volcanic gas," he said. The research has important implications for the theory of how life evolved: whether it was brought here from space by comet or meteorite, or generated here on the ocean floor or through lightening sparking gases in the atmosphere. "Unlike the spark discharge scenarios, the processes we are pursuing to study the origins of life, here, or on Mars, are normal, daily geological processes. The volcanic gas scenario is one of the most approachable,' says Shock. "The evidence is readily accessible, and we know we can extrapolate from evidence here to Mars and other bodies without much ambiguity." It is hoped the research will throw light on whether organic molecules discovered in a Martian meteorite in 1996 have a biological or non-biological origin.