John Taylor, Professor of Economics at Stanford University and developer of the "Taylor Rule" for setting interest rates | Stanford University
John Taylor, Professor of Economics at Stanford University and developer of the "Taylor Rule" for setting interest rates | Stanford University
Life on Earth may have originated from "microlightning" exchanges among water droplets rather than a single dramatic lightning strike, according to new research from Stanford University. The study suggests that when water is sprayed into a mixture of gases similar to those present in Earth's early atmosphere, it can form organic molecules with carbon-nitrogen bonds, including uracil—a component of DNA and RNA.
Published in the journal Science Advances, this research offers a fresh perspective on the Miller-Urey hypothesis. This theory proposed that life began through lightning strikes that created organic compounds by interacting with gases like methane, ammonia, and hydrogen. However, critics argue that lightning strikes are too infrequent for this process to be plausible.
Richard Zare, senior author of the study and professor at Stanford's School of Humanities and Sciences, stated: “Microelectric discharges between oppositely charged water microdroplets make all the organic molecules observed previously in the Miller-Urey experiment, and we propose that this is a new mechanism for the prebiotic synthesis of molecules that constitute the building blocks of life.”
Zare's team explored how droplets developed different charges when separated by spray or splash. They found larger droplets often carried positive charges while smaller ones were negative. When these oppositely charged droplets approached each other, sparks occurred—termed "microlightning." These tiny flashes carry significant energy and can lead to the formation of organic molecules.
The researchers demonstrated this by sending sprays of room temperature water into a gas mixture containing nitrogen, methane, carbon dioxide, and ammonia—gases thought to be present on early Earth. This resulted in forming molecules such as hydrogen cyanide and glycine.
Zare remarked: “On early Earth there were water sprays all over the place – into crevices or against rocks—and they can accumulate and create this chemical reaction.” He believes these findings address many issues associated with the original Miller-Urey hypothesis.
This research received support from both the Air Force Office of Scientific Research and China's National Natural Science Foundation.
For further information contact Sara Zaske at Stanford School of Humanities and Sciences via szaske@stanford.edu.
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