Document Analysis NLP IA
FREQ, RAKE or TFIDF
Summary (IA Generated)
So it’s no wonder that a report published in Nature Astronomy that the upper levels of Venus’ atmosphere contain a molecule that is a potential signature of life, comes as something of a shock.
The fact that this molecule is nevertheless present in our oxidizing atmosphere is because it is continuously produced by microbes.
So phosphine in the atmosphere of a rocky planet is proposed to be a strong signature for life.
It shouldn’t be stable in the atmosphere of a planet like Venus where it would be rapidly oxidized unless, like on Earth, there is a constant new supply.
So why were the authors of the study looking for phosphine in such an unpromising environment? Venus was to supply the “baseline atmosphere” of a rocky planet, free from a phosphine biosignature.
Scientists investigating rocky exoplanets would then be able to compare the atmospheres of these bodies with that of Venus, to identify any potential phosphine biosignature.
So to find a global concentration of the molecule around 1,000 times higher than that of Earth was something of a surprise.
It unambiguously indicated the presence of phosphine, so a second set of data was recorded, using a different instrument on a different telescope.
Phosphine is present in Venus’ atmosphere, with a patchy distribution across the mid-latitudes, decreasing towards the poles.
Phosphorus in Venus’ atmosphere was measured by the (former Soviet Union) Vega probes and found to occur as the oxidized molecule P₄O₆.
In looking to explain the presence of phosphine, astronomer Jane Greaves from the University of Cardiff and her team used the Vega data and modeled almost 100 different chemical reactions in the atmosphere to see if they could recreate the phosphine they’d found.
They even considered reactions below the surface, but Venus would have to have volcanic activity at least two hundred times greater than that of Earth to produce sufficient phosphine in this way.
They considered this too, but found it wouldn’t lead to the amounts of phosphine the data indicated.
The team also considered whether reactions with lightning or the solar wind could create phosphine in the atmosphere but discovered only negligible quantities would be produced this way.
Phosphine is present in Venus’ atmosphere at concentrations way above the level that can be explained by non-biological processes.
Does that mean there are microbes present in Venus’ atmosphere, sailing through the clouds in aerosol droplets – a Venus fly-trap at the micro-scale?.
It may be that astrobiologists searching for life beyond Earth now have an additional atmospheric biosignature about which to argue.