Originally I wrote this article in early January of this year so some bits may be out of date by now but I don’t think it really matters. Also if I were publishing these articles in the order they were originally written this one should be about astro-photography but given the recent comments by Brian Cox around his thoughts on the existence of extra-terrestrial life I thought while it was topical I might as well put forth my musings on the subject. The picture near the end of the article comes from wikipedia so I can’t say how accurate it is but I think it is close enough for the point it's trying to make. I'm also not entirely sure how the picture will come out but hopefully it will be legible.

I wonder if this year will go down in history as the year mankind discovers that we are not alone in the Universe. With all the stuff we have going on at the moment you’d think we were getting close to an answer. The number of extra solar planets discovered has now reached one thousand and data from the Kepler spacecraft continues to redefine our view of how many earth like planets there may be lurking in our galaxy as well as just what the extent of a habitable zone around a star might be. Not only that but we also have NASA’s nuclear powered curiosity rover that was delivered to the red planet in a way that wouldn't have looked out of place in an episode of Thunderbirds. Although its primary mission isn't to look for life, having a rover the size of a Mini trundling around the red planet drilling rocks, analysing samples and vaporising bits of scenery with its laser will hopefully stand a good chance of proving whether life has ever existed there. Most recently we have the news that the Rosetta spacecraft has woken up on its way to chasing down comet 67P/Churyumov-Gerasimenko in order to land a probe on it. It is all tremendously exciting stuff which you’d hope might just mean that this is the year we finally answer that cosmic conundrum.

It really would be mankind’s most stunning scientific discovery if we could finally put that question to bed with a ‘no, we’re not alone’ answer and move on to more entertaining thoughts such as ‘What do our alien neighbours look like?’, ‘What sort of weapons do they posses?’ or even ‘I wonder how they’d taste with some fava beans and a nice Chianti?’

Discussing the possibility of extra terrestrial life though can be problematic because it sometimes leads to the sort of conversation that involves believing aliens are whizzing around our planet turning cows inside out and probing the kind of people that turn up on The Gerry Springer show or Jeremy Kyle.

However that does I suppose help to frame the range of possibilities and their probabilities. So at one end you have simple organisms such as bacteria which could be very likely to exist on other planets or moons, to the other extreme of having technologically advanced, bovine bothering aliens whizzing around in spaceships which almost certainly do not.

Personally I very much subscribe to the idea that there are alien life forms of some sort out there. I hope life turns out to be quite common in the universe as long as a planet’s star is capable of simmering a soup of water and organic chemicals for a few billion years. But the question of intelligent life is much trickier because while it may be that creating simple organisms is a fairly easy task, where things go from there is purely driven by evolution so it is both a slow and fairly random process. We know this for ourselves because if not for the fortuitous catastrophe of a huge asteroid or comet hitting the earth a few million years ago and helpfully wiping out the dinosaurs we almost certainly wouldn't be here now.

While any discovery of extraterrestrial life would be exciting it is really intelligent life, perhaps one with a technology like ours or even greater than ours that most people find appealing, but what are the odds?

Well, if we look at the Earth, current estimates put the number of species on the planet today at around the 9 million mark and that doesn't include bacteria or other micro-organisms. If you add in everything that has ever existed on earth over the eons I don’t think it unreasonable to add a couple of zero’s to that figure but we can say with some certainty that we are the only intelligent creatures to have evolved so far. Sure we are told dolphins are pretty smart but since they live in an ocean with only a pair of flippers and a tail to work with it’s difficult to imagine how they could ever discover fire, need to invent the wheel or experiment with electricity. And look at our closest relatives the apes. Practically identical to us at a DNA level and in possession of those handy opposable thumbs yet the height of technology that our simian cousins have developed so far appears to be using a stick to go fishing for ants.

So it would seem that we are at the very least something of a billion to one chance. That does sound like pretty long odds, but given the vastness of our galaxy never mind the universe, astronomical odds would still suggest we are not alone in being the only intelligent, technological race out there.

But if there are intelligent civilisations out there why have we not heard from them? After all we've been beaming them high quality entertainment in the form of radio and television broadcasts for years. Well, to put that into perspective check out the picture below that shows how far we've been spamming Dr Who and Downton Abbey to anyone with the antenna to listen.

That tiny blue dot isn't the earth, it is in fact what a two hundred light year radius around the earth looks like in our Milky Way galaxy and it’s really not that impressive is it. No surprise then that we've yet to receive any communications requesting an answer to Who shot JR?

It does really highlight the scale of the problem though. Distances within our own galaxy are so vast that even the speed of light is a bit sluggish if we’re hoping to detect stray radio emissions from another world. Still, it’s good to be optimistic and even though the odds may be very, very long, we might yet be lucky and pick up Rigel’s got talent sometime soon.

Personally I think it will be more exciting when we put some technology into space that will allow us to observe the chemical signatures from exoplanets atmosphere with sufficient accuracy to determine the elements that are present and in what volumes and therefore infer the presence of biological entities. Having the capability to do that should allow us to detect signs of life on planets where the local wildlife exists but is either too stupid or too lazy to come down from the trees and kick off a technological revolution by making fire and inventing the wheel.

Although it may just be that our extra terrestrial neighbours have been so traumatised by the attentions of intergalactic, joy riding aliens and their probes that they’re much happier to stay in the tree tops and hope the rest of the galaxy doesn't come calling.