The presence of phosphine in the Venusian atmosphere can be explained without biogenic sources, according to a study. Phosphine has been reported to be detected in the atmosphere of Venus, leading to the suggestion that the chemical has biological origins. Ngoc Truong and Jonathan I. Lunine used published laboratory data and calculations of volcanism and atmospheric processes to determine whether the presence of phosphine in the Venusian atmosphere can be explained by abiotic means. The authors calculated that small amounts of phosphides may be brought to the surface from deep mantle sources by volcanism, ejected into the atmosphere as volcanic dust during explosive eruptions, and react with sulfuric acid in the aerosol layer to form phosphine. The results suggest that eruptions comparable to Krakatau on Earth would be necessary for phosphides to reach the heights reported. However, the authors suggest, observational data, including episodic spikes in sulfur dioxide at the cloud tops of Venus and variation in the amount of haze seen above the clouds, are consistent with Venus having sufficient levels of ongoing volcanism, as interpreted by earlier work. The authors note that further observations of Venus are necessary to determine whether phosphine is indeed present in the atmosphere. If phosphine is confirmed, the model suggests that Venus is experiencing a modestly elevated epoch of active volcanism, according to the authors.
Article #20-21689 "Volcanically extruded phosphides as an abiotic source of Venusian phosphine," by Ngoc Truong and Jonathan I. Lunine.
MEDIA CONTACT: Ngoc Truong, Cornell University, Ithaca, NY; email: < tnt45@cornell.edu >; Jonathan I. Lunine, Cornell University, Ithaca, NY; tel: 607-255-5911, 520-241-4739; email: jlunine@astro.cornell.edu
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Proceedings of the National Academy of Sciences