Phosphine in the Venusian Atmosphere: A Strict Upper Limit from SOFIA GREAT Observations

Abstract

The presence of phosphine (PH${}_3$) in the atmosphere of Venus was reported by Greaves et al. (2021a), based on observations of the J=1-0 transition at 267 GHz using ground-based, millimeter-wave spectroscopy. This unexpected discovery presents a challenge for our understanding of Venus's atmosphere, and has led to a reappraisal of the possible sources and sinks of atmospheric phosphorous-bearing gases. Here we present results from a search for PH${}_3$ on Venus using the GREAT instrument aboard the SOFIA aircraft, over three flights conducted in November 2021. Multiple PH${}_3$ transitions were targeted at frequencies centered on 533 GHz and 1067 GHz, but no evidence for atmospheric PH${}_3$ was detected. Through radiative transfer modeling, we derived a disk-averaged upper limit on the PH${}_3$ abundance of 0.8 ppb in the altitude range 75-110 km, which is more stringent than previous ground-based studies.

arXiv commentAccepted for publication in Geophysical Research Letters

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Cited by in corpus (6)

• Dynamics and Clouds in Planetary Atmospheres from Telescopic Observations
• Astrobiological Potential of Venus Atmosphere Chemical Anomalies and Other Unexplained Cloud Properties
• Recovering Phosphine in Venus' Atmosphere from SOFIA Observations
• Venus Cloud Research: Progress and Perspectives
• Communicating astrobiology and the search for life elsewhere: speculations and promises of a developing scientific field in newspapers, press releases and papers
• Limits to dynamic range in GHz-THz single-dish planetary spectra