Searching for Phosphine (a Possible Biomarker) in the Atmosphere of Venus:  Now You See it - Now You Don't

 

Martin Cordiner

Research Associate Professor
The Catholic University of America
NASA Goddard Space Flight Center

Wed, February 15, 2023 - 4:00 PM
Karl Herzfeld Auditorium of Hannan Hall - Rm 108

The presence of phosphine (PH3) in the atmosphere of Venus was recently reported based on observations using the Atacama Large Millimeter/submillimeter Array (ALMA) and the James Clerk Maxwell Telescope (JCMT). 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 PH3, for example, from photochemical, geochemical, meteorological and even biological processes. The claimed detection of PH3, however, was contested by several subsequent, independent analyses of the ALMA and JCMT data, and searches for infrared signatures of PH3 using other ground and space-based instruments have resulted in non-detections. Phosphine on Venus remains a serious topic for discussion in the planetary science community due to its potentially profound implications, and the fact that Pioneer Venus mass spectrometry is also consistent with the presence of PH3. In this talk, I will examine the previous ALMA and JCMT detections, and present new results on a sensitive search for PH3 on Venus based on observations made using the SOFIA airbourne observatory, over three flights in November 2021.

Refreshments served at 3:45 PM

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