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NOTE: In this telecon, we will hold our questions until the end. Jane promises that there will be plenty of time for them.
Phosphine is a mysterious biomarker on Earth, and controversially, its presence on Venus could hint at a zone in the clouds inhabited by micro-organisms. The J=1-0 rotational line has been identified at 4 epochs but is still strongly debated. In case some other mysterious (uncatalogued) absorber is present at the J=1-0 frequency, it is important to recover another rotational line. Cordiner et al. used SOFIA/GREAT to observe Venus in evenings of Nov 2021, and infer a limit <0.8 ppb of PH3 from the J=4-3 line. Examining their Level 1 data, it is apparent that fringing artefacts arise from the calibration loads, which are not vital to get absorption line-depths. Using only On-Off data gets slightly cleaner results, and a candidate 4.5-sigma detection is made of 1.5 ppb of PH3. We also spotted that SOFIA and JCMT/ALMA have observed Venus in evenings and mornings respectively, for diverse operational reasons. In fact, all the published data can be reconciled if sunlight destroys PH3 over a day in the Venusian atmosphere, to a similar degree to the losses on Earth.