Scientists studying the origin of life in the universe often focus on a few essential elements, most notably carbon, hydrogen, and oxygen. But two new papers highlight the importance of phosphorus for biology: an assessment of where things stand with a recent claim about possible life in the clouds of Venus, and a look at how lightning reduction of phosphorus fertilizers may be essential for life. early in the history of our own planet.
First some biochemistry: Phosphine is a phosphorus reducer with one phosphorus atom and three hydrogen atoms. Phosphorus is also found in its reduced form in the phosphide mineral schreibersite, in which the phosphorus atom binds to three metal atoms (either iron or nickel). In its reduced form, phosphorus is much more reactive and useful for life than phosphate, where the phosphorus atom binds to four oxygen atoms. Phosphorus is also the richest element in biological molecules compared to non-biological molecules, so it’s not a bad place to start when you’re hunting for life.
In the second of the new papers, Benjamin Hess of Yale University and colleagues highlight the contribution of lightning as a source of reduced phosphorus compounds such as schreibersite. It has long been recognized that meteorites provided much of the reduced phosphorus needed for the origin of life on Earth. But Hess believes electronic value has not been underestimated. For one thing, lightning was much more common early in the history of our planet. The authors estimate that it can produce up to 10,000 kilograms of reduced phosphorus compounds each year – which may be enough to start life, especially since we don’t know what the degree of phosphorus reduced from remaining meteorites (in that form) the impact on Earth.
Hess ‘s study is interesting to me, because if lightning is so important, we are back to the “Darwin’ s little lunch” setting for the beginning of life that Miller and Urey tried to imitate in their famous 1950s experiment.
In terms of life potential in the Venusian atmosphere, how has that claim been sustained in the seven months since the original paper was published? Well, it’s still controversial. Some scientists claim that the reported observations reported that they recognized sulfur dioxide. But another recent paper claims to have found phosphine in ancient data from the Pioneer-Venus mission. The recent controversy prompted the original authors to review their claim and correct the phosphine level down to 1-4 parts per billion worldwide, but otherwise they stood by the lorg.
If we assume that the measured phosphine concentrations at Venus are true, then we must (A) propose an unknown method for the production of this element, which is difficult in an oxidizing atmosphere, or (B) give biology, which is also difficult to accommodate water scarcity and hyper-acidity in the Venusian atmosphere. Of course, any life forms would have to depend on biochemical changes unknown to Earth.
In other words, there is no clear answer after seven months. But in a recent paper I offer a few suggestions on how you can move forward. The first goal should be to determine the trace of phosphine by looking in the infrared spectrum, and also to detect related phosphorus fertilizers, which should be present if phosphine is present. Then I recommend doing lab tests to test how acid-loving microbes can change over several generations. to the very high acid concentrations of sulfuric found on Venus. Could they survive without the orderly metals found on the surface of a planet, but would be missing in Venusian clouds? Finally, can we think – theoretically at least – of possible ways to change biochemical change in such an alien environment?
But when the Venus phosphine debate comes out, the results of these studies would be interesting and relevant in finding life on exoplanets. And second, phosphorus will continue to be vital for our thinking about life on Earth and beyond.
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