The statistical reliability of 267 GHz JCMT observations of Venus: No significant evidence for phosphine absorption

TL;DR

This study reanalyzed 267 GHz JCMT observations of Venus to assess the claimed phosphine detection, finding no statistically significant evidence and highlighting the potential for false positives in spectral analysis.

Contribution

It provides an independent statistical reanalysis of the JCMT data, demonstrating the absence of significant phosphine absorption signals in Venus's atmosphere.

Findings

No significant phosphine detection in JCMT data

Polynomial fits can produce false positives

Reanalysis aligns with other studies questioning phosphine presence

Abstract

In the light of the recent announcement of the discovery of the potential biosignature phosphine in the atmosphere of Venus I present an independent reanalysis of the original JCMT data to assess the statistical reliability of the detection. Two line detection methods are explored, low order polynomial fits and higher order multiple polynomial fits. A non-parametric bootstrap analysis reveals that neither line detection method is able to recover a statistically significant detection. Similar to the results of other reanalyses of ALMA Venus spectra, the polynomial fitting process results in false positive detections in the JCMT spectrum. There is thus no significant evidence for phosphine absorption in the JCMT Venus spectra.