The greatest discovery to come
Is there intelligent life in our galaxy? The chances are good but probably we don’t have to go that far. First, let’s not talk about the ufology, the Roswell incident, little green men, bigger grey men, etc. I love science-fiction, but we have to stick here to science, not fiction. Thus, we talk about things that can be proved scientifically.
Still, we can’t escape some sci-fi, at least, as a starting point. Sir Arthur Clark, a great sci-fi author, in his famous book ‘2001: A Space Odyssey’ proposed the opportunity of an alien, even intelligent life, on Europa, Jupiter’s satellite. Europa is covered with thick layer of water ice with an ocean just beneath it, an ocean of unknown depth and mysteries. Now forget the sci-fi as NASA plans a mission there to explore the opportunity of life just like Sir Arthur has proposed back in 1968. Probably an intelligent alien life is much closer than we might guess.
Another place within the Solar system to look at is Enceladus in the Saturn system. It has the same pattern as Europa: water ocean under the ice surface. Unfortunately, Mars, the former favorite since H.G. Wells’ times, is out of the race now. The best thing we can get there is bacteria hidden under the sand and stones of its endless deserts… By the way, the 1976 ‘Viking’ lander life-searching experiment results are still considered by its project leader controversial, though NASA has officially denied its positive outcome. Probably, the coming-soon ExoMars mission will finally answer the question: Is there life on Mars?
What about more distant places? We, Earthlings, live in the so-called ‘habitable zone’ that requires a Sun-like single star, a quite small stone planet with liquid water on its surface, a stable orbit with a definite distance from the local sun, a thick but not-too-thick atmosphere to avoid asteroids and UV-rays and, probably, a Jupiter, again, to thwart off comets from entering too close. And, yes, we are talking about life as we know it, a carbon-based life with water as the pre-condition. Other life forms like some pure-energy entities are still in sci-fi territory.
So we’re looking for Earth-like planets in our galaxy. Recently, hundreds of exoplanets, mostly gas giants, useless for our purposes, have been discovered by NASA’s Kepler Space Observatory, which is itself a revolutionary thing in space exploration. How many of them are Earth-like ones? How many of these distant Earth-like worlds can harbour life?
Now more than a thousand exoplanets have been discovered but only a handful of them are true Earth-like planets, orbiting Sun-like stars in the “Goldilock’s zone”. The current champion here is the Kepler-452b orbiting a Sun-like star (G-class). This is almost an Earth-twin, just a little bigger. As of right now, there are only about 15 such planets discovered.
Statistically, we can guess that there are many more of Earth-like planets in the habitable zone to be discovered in our galaxy in years to come. At the same time, current technology can’t detect life there even if it exists.
It is already proved at this point that there are hundreds of planets out there and some of them have a chance to support life as we know it. NASA’s JPL study of 2011 estimates that around ‘1.4 to 2.7 percent’ of all stars of spectral class F, G, and K in the Milky Way, i.e. our galaxy, are expected to have planets in their habitable zones, which makes it literally billions of planets! Other studies, such as the one of 2013 conducted by Ravi Kumar Kopparapu, a Penn State astrobiologist, propose much bigger numbers, making it somewhere between 95 – 180 billion (!) habitable planets in our galaxy. To make a long story short, I believe there is a good scientific chance that we are not alone and there are some other ‘pale-blue dots’ as Carl Sagan famously put it, or Earth-twins.
It is only a question of time when we will find Them. Or They will find us. And another thing, are we really going to be happy to meet Them?
Is there intelligent life in our galaxy?
I really really want there to be…..
The maths look simple enough. One of our planets in our solar system, going around our sun, is full of intelligent life. So surely, multiply that by billions and billions of stars that make up our galaxy, many of whom also have several planets orbiting, and you are left with the huge probability that some life, somewhere out there, also exists.
Sadly, or maybe not sadly, who knows, it’s nowhere near that simple.
The fact that my two friends are also writing at this time, the fact that our families are in the next room to us, the fact that you, yes you, are reading this, amounts to a miraculous and enormous sequence of fortuitous events to allow all this to happen.
Forget the extraordinary journey that our father’s sperm had to take, that we survived our gestation period and our birth, and managed to keep alive until this moment, forget all that.
Just consider the odds against our planet being just the perfect place to provide us with the platform to allow our journey through life.
Our Earth is neither too hot nor too cold – not too big nor too small – and by a complete fluke, it has sufficient water which is essential for life as we know it.
We don’t wobble on our journey round the sun, (not good for life sustenance, apparently) and even when a large meteor collided with the earth, life went on. We are in a position in our galaxy where there appears to be less bad activity like radiation from supernovas and many other ugly happenings.
However life started, it appears to be extremely rare, where all life forms evolved from just one point in Earth’s history, rather than independent life-forming creations constantly happening throughout our existence. It took at least three and a half billion years for intelligent life to evolve here, so the whole process takes a lot of time and luck for this to happen.
Back to my first paragraph. For most of my life, I believed the odds on other life forms, as we know it, would be a mathematical certainty.
If there was other intelligent life, why haven’t they made themselves apparent yet? Maybe they are behind us in technology, and it will take them (or us) another few thousand or million years to get the technology to transport signals through millions of light years distance. Maybe they are sophisticated enough to have discovered us already, but are satisfied that, as a species, we are so stupid that we appear to be killing each other, and even more disturbingly, that we appear to be killing the very planet that gave us life in the first place. What extra-terrestrial could possibly want to make contact with us raging idiots?
As much as I really, really want there to be other life forms in the universe, to once and for all put to bed the theory that we are the only intelligent living beings ever, (upon which all religions revolve) I know that, not only in my short lifetime, but for much of the remainder of mankind’s existence on Earth, there will never be any evidence to prove it.
Of course, I am talking about life as we know it – you know, two eyes, a brain, etc. Maybe there are forms of life that do not require what we do to survive. Maybe they are here already…………
Don’t look behind you…….
The Fermi Paradox
I am optimistic when I should not be. I sincerely believe in people, I know we are capable of so much more and that anyone armed with common sense can see these facts as clearly as I can.
You will not be surprised to discover that this childish, glowing outlook extends to the question of life out there. Perhaps a few stats are in order:
- Roughly 200 billion stars are in our galaxy
- Over 100 billion planets fill our Milky Way
- Most G Type stars have at least one rocky, earth-like planet.
I don’t care what odds you want to give advanced life forming, there will be thousands of stars hosting advanced societies. Because of the size of our galaxy, it is likely that the nearest advanced society is a couple of hundred light-years away. It is this distance makes that makes them hard to locate.
Now, on to this “Fermi Paradox” business: if the universe is so big and old, where are all the alien civilizations? There is much more to The Fermi Paradox than that but that’s good enough for now. The geek in me also wants to rattle on about the Drake Equation but I will spare you the science lecture.
So, Dean contends that Roger’s taste in wine blows and that his knowledge of the universe is pathetic. Yet, we can all agree that the Fermi Paradox is on Roger’s side.
Where are all the little green men if they have thousands of planets on which to land? May I offer several theories?
- The Star Trek version is real; Federation like Scientist land on a planet and hide behind high-tech blinds. Observing us but not interfering. Prime Directive and such making contact impossible.
- There is no such thing as faster than light travel. This may be my favourite… If it takes thousands of calendar years to travel hundreds light years, nobody is coming to our party. Einstein was right after all.
- We simply suck and nobody wants to chat. I think this one is unlikely. I would argue that they may not want to chat because they have seen what contact has done to other civilizations in the past.
- They find our war-like tendencies off-putting and are frightened off. Again, not likely; that’s a bit like saying the Royal Marines could not deal with a couple of dudes in a cave with clubs.
Obviously, I can go on for days with this stuff but you get the point. Roger has the evidence and Dean has the number of planets and the odds. This could go either way.
We started our journey with the Earth at the centre of the universe. Then we understood that we revolved around the Sun. Our parents would remember when the first galaxies outside our own were discovered (the Hale Telescope). Now, we are again asked to believe that we are somehow special. At what point will we stop expecting Columbus to sail off the edge?