GREENBELT, Md. - Lightning and gases from volcanic eruptions could have given rise to the first life on Earth, according to a new analysis of samples from a classic origin-of-life experiment by NASA and university researchers. The NASA-funded result is the subject of a paper in Science appearing October 16.
"Historically, you don't get many experiments that might be more famous than these; they re-defined our thoughts on the origin of life and showed unequivocally that the fundamental building blocks of life could be derived from natural processes," said lead author Adam Johnson, a graduate student with the NASA Astrobiology Institute team at Indiana University, Bloomington, Ind.
From 1953 to 1954, Professor Stanley Miller, then at the University of Chicago, performed a series of experiments with a system of closed flasks containing water and a gas of simple molecules. At the time, the molecules used in the experiment (hydrogen, methane, and ammonia) were thought to be common in Earth's ancient atmosphere.
The gas was zapped with an electric spark. After running the experiment for a few weeks, the water turned brown. When Miller analyzed the water, he found it contained amino acids, which are the building blocks of proteins -- life's toolkit -- used in everything from structures like hair and nails to processes that speed up, facilitate, and regulate chemical reactions. The spark provided the energy for the molecules to recombine into amino acids, which rained out into the water. His experiment showed how simple molecules could be assembled into the more complex molecules necessary for life by natural processes, like lightning in Earth's primordial atmosphere.
Miller came to the Chemistry Department at the University of California, San Diego in 1960. Professor Jeffrey Bada, a co-author of the paper, was his graduate student in chemistry between 1965 and 1968. Bada joined the faculty of the Scripps Institution of Oc
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NASA/Goddard Space Flight Center