Life Jim, but not WHERE we know it

I had planned to spend today sanding a table we have been gifted (more on that later in the week I hope), but at 4pm I found myself sat in my kitchen watching a live press briefing from the Royal Astronomical Society. Usually, this would be a rather dry affair, if a live press briefing would happen at all, but today was different, because today the briefing was to announce what could potentially be the greatest discovery in the history of humanity, and I don’t think I am exaggerating there.

For what was announced in the briefing was the discovery of life on another planet, or more accurately chemical signatures in Venus’s atmosphere which could suggest microbial life in the upper cloud layers. For those interested you can read the paper here.

For those of you looking for the brief summary, what the scientists have found is the presence of relatively small amounts of phosphine gas in the upper atmosphere of Venus. This might not sound like the most exciting discovery until you consider the source of the phosphine.

Phosphine could be present in the atmosphere through a variety of chemical reactions, but when the scientists crunches the numbers, the known chemical pathways would not be able to produce the quantities of phosphine seen, even though the actual quantity is low.

A second hypothesis the authors suggest is some unknown exotic chemical process which could produce sufficient amounts of phosphine. The astute amongst you might be thinking this is not an answer at all, but if this is the solution it would certainly be an exciting prospect and would advance our knowledge of the universe once understood.

But there is of course a third possibility to explain the presence of phosphine is the presence of life in the atmosphere. Phosphine is a biochemical byproduct on Earth, and so it is possible that simple microbial life is present in the Venusian atmosphere.

When I woke up this morning, there was only one planet in the entire Universe we knew for certain life existed on. As I sit here writing this now, that remains the case, but we are one step closer to potentially confirming the existence of life on another planet.

For the technical details of the study, what I have described above is about where my understanding finishes (although the paper is fairly accessible as far as academic papers go). What I have spent the rest of the day thinking about is the implications for us if the discovery is proved to be the result of life, and assuming that life originated on Venus (rather than for example being seeded from Earth or hitching a ride on one of the probes we have sent to explore the planet).

There remains a sizeable proportion of people who continue to believe human beings are in some way special and separate from the rest of life on Earth. Some people speak of a soul or spirit, or if they do not name it directly, at least imply humans have some unique quality which sets us apart from the rest of the animal world.

Of course we do have unique qualities and abilities, language use and complex tool making to name just two, but fundamentally, we are just animals like every other species on the planet.

Those who have accepted this reality might still find some comfort in the special nature of Earth as the only planet known to be home to life. Of all the billions and billions of stars in our galaxy alone, orbited most likely by another order of magnitudes worth of planets, only one contained life, was special.

But if life, even if that life is simple, exists on another planet, the unique nature of our existence suddenly becomes commonplace. Humanity is not the centre of the universe, and neither in life on Earth.

You can probably guess from my tone that I do not hold to either view. Humans are just one of a multitude of animals, and life on Earth is just a fortuitous accident. I am not one who ascribes to the idea we have a special place in the Universe.

Rather, today’s announcement has me extremely excited.

On the one hand, I am cautious like the authors. Their findings do not confirm the existence of extraterrestrial life, merely offering the tantalising possibility.

On the other hand, the existence of life on our nearest neighbour would suggest the Universe is teeming with life. Life on two planets within relative spitting distance would be too much to be simply coincidence. The odds of life on just one planet alone is astronomically (excuse the pun) high, the odds of life forming independently on just two planets in the Universe is another magnitude again. The chances of those two planets being near neighbours in the same star system, well…

On the face of it, today’s announcement is something interesting only to planetary astronomers and biochemists. The authors are certainly not claiming anything more than an interesting finding. But to me, and I am sure many, many more people around the world, today’s announcement is groundbreaking. For the first time in human history, we are a step closer to answering the question are we alone in the Universe? If this finding proves to be true, it will not be little green men in spaceships, but it will just as fascinating none-the-less.