Researchers find mist droplets make RNA parts

Stanford University researchers reported on March 14, 2025 that sprays of ordinary water can generate tiny electrical discharges strong enough to drive chemical reactions in nearby gases. The team said those reactions produced organic molecules with carbon-nitrogen bonds in laboratory tests designed to mimic parts of Earth’s early atmosphere. The study appeared in *Science Advances* and was led by Yifan Meng, Yu Xia, Jinheng Xu and senior author Richard Zare. Zare said the findings point to a possible route by which water spray from waves or waterfalls could have helped generate some of life’s chemical precursors. ### How did plain water droplets end up making reactive chemistry? The *Science Advances* paper said neutral water, when sprayed, separates into oppositely charged microdroplets. The researchers reported that larger droplets tended to carry positive charge while smaller droplets tended to carry negative charge. When those droplets approached each other, the paper said, electrons jumped between them and produced a discharge accompanied by light emission. (science.org) Richard Zare, a Stanford chemistry professor, said those “microelectric discharges” occurred without any externally applied voltage. The paper said the discharge was energetic enough to excite, dissociate or ionize surrounding neutral gas molecules, giving the droplets a way to trigger chemistry in the gas around them rather than only inside the liquid itself. ### What exactly did the team make in the lab? (science.org) The Stanford group reported that spraying room-temperature water microdroplets into a gas mixture containing nitrogen, methane, carbon dioxide and ammonia led to the synthesis of organic molecules containing carbon-nitrogen bonds. Stanford’s summary of the work said those products included uracil, one of the components of RNA and DNA. March 14, 2025 coverage from Stanford said the work connected the droplet discharges to compounds relevant to amino acids, proteins and nucleic acids. (science.org) The paper itself described the chemistry more cautiously as formation of organic molecules in the surrounding gas, while the university summary highlighted uracil as a specific example. ### Why are researchers linking this to the origin of life? (science.org) The 1952 Miller-Urey experiment showed that electricity applied to a mixture of water and simple gases could produce organic compounds. Stanford said the new work offers a version of that chemistry that does not require a large lightning strike, because the charge separation arises when water is sprayed into fine droplets. (science.org) Zare said the droplet discharges made “all the organic molecules observed previously in the Miller-Urey experiment,” and he proposed the process as “a new mechanism” for prebiotic synthesis. That interpretation was his, and the paper framed the result as a “possible mechanism” for making building blocks of life on early Earth. ### Where would this happen outside a laboratory nozzle? (biox.stanford.edu) Stanford’s March 14 summary pointed to crashing waves and falling water as natural settings where sprays of charged droplets are common. The paper also cited earlier observations that water droplets at the base of waterfalls carry charge, and said aqueous aerosols can contain both positive and negative droplets. (biox.stanford.edu) The authors said that matters because water sprays are widespread in nature. In their account, repeated small discharges among many droplets could provide a more frequent source of reactive chemistry than rare lightning strikes over a large ocean. ### What should readers be careful not to overclaim? The March 14 paper did not show that life began in sea spray or waterfall mist. (biox.stanford.edu) The experiments showed that sprayed water microdroplets can create electrical discharges and drive formation of organic molecules under controlled laboratory conditions. The named next step in the published work is further study of microdroplet chemistry and its relevance to natural environments. (biox.stanford.edu) The paper is “Spraying of water microdroplets forms luminescence and causes chemical reactions in surrounding gas,” published in *Science Advances* by Yifan Meng, Yu Xia, Jinheng Xu and Richard N. Zare. (science.org)