Today, 14th September 2020, the Royal Astronomical Society (RAS) held a virtual press conference via Zoom for what could be one of the most significant discoveries in decades. A group of researchers from MIT, the University of Manchester and University of Cardiff have found a gas called phosphine in the atmosphere of Venus. They made the discovery using the Atacama (ALMA) array located in Chile and the James Clerk Maxwell telescope located in Hawaii. The discovery was published in the Journal of Nature Astronomy.
What’s so important about phosphine?
In various studies, phosphine is shown to be what is called a bio-signature. This means that it is possible that the gas is produced by microbial life on Venus rather than geological processes. Phosphine is produced naturally on Earth by life and in labs. However, we know there are no labs or factories on Venus and the team also say the amounts observed can’t be explained by any known chemical processes. They looked at various mechanisms by which the phosphine could be created such as chemical processes, volcanism and lightning but could not find any method that would produce the levels observed.
Why is that important?
As mentioned above, the team working on these observations looked at all of the known methods of phosphine production. If it turns out that life does not exist on Venus then that means there is some, as of yet unexplained geological or chemical process active on Venus.
If it is the case that the phosphine in the atmosphere of Venus is produced by microbial life, the implications for us are profound. So far, we have no evidence of life beyond Earth. The only place we know life exists is here. If it is proven that life also exists on Venus then that has massive implications for life beyond Earth. If life formed, or travelled to Venus, it may well also have done the same on other planets and moons in the Solar System and even beyond. It would mean that we are not alone in the universe.
Does this mean there is life on Venus?
No. The team working on this were keen to stress that this is not proof that there is life on Venus. After looking at all of the mechanisms of phosphine production the team were unable to find an explanation for the levels of phosphine observed. It is also worth noting that given the acidic nature of the atmosphere on Venus, the phosphine would not be long lived. This means that whatever is producing it, is replenishing it. The two methods the team are left with is either some unknown chemical or geological process or microbial life.
The conditions on Venus are very harsh. The surface of the planet has temperatures of over 400 degrees C and crushing pressure. Any spacecraft humans have managed to land on Venus were very quickly destroyed. In addition to the temperature and pressure the atmosphere is full of sulfuric acid. Venus really is a very unpleasant place to live. This is not to say it is all like that, or always was like that. There is evidence that Venus once was a much more hospitable world with water on the surface. Even now, at a height of 50km into the Venusian atmosphere, the temperature and pressure are very similar to Earth. It’s not impossible to think of a life-form that could live in the atmosphere, but this would be very different to the life we have on Earth. There are bacteria on Earth that live in the upper atmosphere.
How will we find out more about this discovery?
The best way to find out more about this will be to send a mission to Venus to explore the atmosphere. In the past, the Russians have used balloons to explore the atmosphere on Venus. Recently, NASA have asked for outline submissions of ideas for a flagship mission to Venus in the 2030s. Today’s research paper will likely influence the design of this and other future missions to Venus. For decades there has been a huge focus on the exploration of Mars, partly fuelled by the prospect of Mars being home to life in the past or even today. The discovery will likely ignite a much greater interest in the study of the planet Venus, Earth’s evil twin.