Tiny Bolts of Lightning Produced by Water Droplets May Have Sparked Life on Earth
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Art and literature have often depicted the creation of life with big, dramatic moments often involving electricity.Mary Shelleys Frankenstein got zapped into action. Michelangelos God (after six REALLY busy days) seemed to send an invisible but palpable spark into Adams extended finger, waking him into existence on the Sistine Chapels ceiling.The same is true for one scientific theory of lifes creation on Earth.Lightening and Life CreationThe theory states that a lightning bolt struck the ocean, triggering a chemical chain reaction that transformed inorganic compounds into organic ones. That scenario, called the Miller-Urey hypothesis, arose from a 1952 experiment showing that a mixture of water and inorganic molecules could produce organic ones after electricity was applied to the mix.Now, a new experiment demonstrates that life could have formed through much smaller and less dramatic electrochemical interactions, according to a paper in Science Advances.Tiny Volts of MicrolightningStanford University researchers sprayed water into a mixture of gases thought to have existed in Earths early atmosphere. That spray, by itself, produces small electrical charges. Then, the tiny volts which the researchers call microlightning coax inorganic molecules to transform into organic ones, including uracil. That molecule, with its carbon-nitrogen bonds, is a key component of both DNA and RNA.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, Richard Zare, a Stanford chemistry professor and an author of the paper, said in a press release.Scientists believe that Earths chemistry set had plenty of chemicals swirling about its first few billion years of existence. However, the theory is that there were few, if any, organic compounds in the mix especially ones with that essential carbon-nitrogen bond.The Miller-Urey experiment provided one possible explanation for how gases like methane, ammonia, and hydrogen could create these organic molecules via lightning strikes. However, the theorys critics say lightning is too infrequent and the chemicals in the ocean too spread about for this to be a workable scenario. Small but Mighty Zare and his team first experimented with how water droplets developed electrical charges when split by a spray or splash. They observed that larger droplets often carried positive charges, while smaller ones were negative. Sometimes, when two oppositely charged droplets got close to each other, sparks jumped between. The process resembles how energy is built up in clouds and then released as lightning.Since these mini bolts are so hard to see, the researchers captured them with high-speed cameras. Despite its small size, microlightning still carries a good bit of energy.Molecular Life SourceNext, the researchers sent sprays of room temperature water into a gas mixture including nitrogen, methane, carbon dioxide, and ammonia gases, all of which are thought to have been around on early Earth. This interaction created organic molecules with carbon-nitrogen bonds.Besides being chemically viable, the researchers argue that this scenario for jump-starting life is much more statistically probable.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, Zare said. I think this overcomes many of the problems people have with the Miller-Urey hypothesis.Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:Discover Magazine. Cooking Up Early-Earth ConditionsBefore joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.
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