What are the prospects for follow-up observations of phosphine on Venus?
This figure is from the paper &quot;Phosphine as a bio signature gas in exoplanet atmospheres&quot;.  It shows the absorption cross section of Phosphine compared to other molecules. We can see that Phosphine has a distinct enough profile from the others molecules in the 7.8-11.5 microns range, with the exception of NH3.  Probing from 2-11.5 microns should then allow to distinguish Phosphine from other molecules. Simulations seem to indicate that current state of the art
nIR ground-based spectrometers could detect phosphine to a minimum of a few ppb, so expect a lot of follow-up observations from the ground in the coming months.