Extraterrestrial Zoology: Is Anybody Out There?

In 2013, it was estimated by scientists that there could be as many as 40 billion planets orbiting red dwarves and stars like our own sun, within the Milky Way alone. These aren't any old planets though, the amount of all planets orbiting stars in our galaxy would be much greater if that were the case. No, there are 40 billion Earth-sized planets, which are in the habitable zones of their stars – the Goldilocks zone, where the planet is at just the right distance from its star to not be too hot, nor too cold. These kind of planets are ideal for life as we know it.

The Statistics

Now, let us, for a moment, imagine the universe - or try to, our brains cannot comprehend the sheer scale. Astronomers have estimated the amount of galaxies in the observable universe, and the number has come to an incredible 100 billion. Assuming that each one of these 100 billion galaxies has a similar amount of habitable planets as the Milky Way, then we can assume that there's a heck of a lot of possibly habitable worlds in the observable universe. But of course, the universe isn't limited to what we can observe. Frankly, we have no idea how big the universe is - some even believe that it could be endless. Other possibilities are that it is part of an immense multiverse, or that the universe comes to an abrupt end, and there is nothing beyond the edges. Whatever the answer, the universe is big. Really big. We can't even imagine its size. So if we take the billions of potentially habitable worlds in the observable universe, then multiply that number by millions, billions, or more, then we end up with the total amount of Earth-like worlds in the entire universe. Unless, of course, the universe is infinite or part of an infinite multiverse, in which case then the amount of Earth lookalikes and potential homes for life is also infinite.

What will aliens be like?

As you can see, there are many planets in the universe which have the potential for being home to life. But why limit ourselves to Earth-sized planets? We are blinkered by our limited knowledge of extraterrestrial life and by our imagination. Life does not necessarily have to exist on an Earth-sized world, or even on a planet at all: what about moons, or indeed even stranger places . . .? One might argue that in the immense, possibly infinite size of the universe, nothing is too far-fetched.

However, we can make educated guesses at what is likely and what isn't. We can guess that life everywhere would follow the basic laws of evolution, and therefore that certain features, such as eyes, mouths, etc, will be good things for an alien to have.

Do they even exist at all?

Of course, some might argue that there might be no aliens out there, that the universe is a lonely place, and that we are something special. Indeed, humans like to think of themselves as unique, and to a lesser extent, that Earth is to. It makes sense that humans might instinctively want for there to be no other life in the universe, because that makes humans and Earth special, and perhaps it also dulls the subconscious fear of other sapient lifeforms. Some argue that the likelyhood of molecules coming together to create lifeforms on more than one planet is simply an impossibility. To balance this out, let us think again of the sheer scale of the Milky Way, of the universe, of what may be beyond, other universes, infinity, whatever train of thought you prefer. I personally think that given the sheer scale that we are talking about here, life will have evolved on many planets. Anything else is, to me, impossible.

So, yes, I think that there is life out there, and that a more worth while train of thought is not 'are aliens real?', but questions about extraterrestrial life, assuming it is real. Where can we find it? What will it look like? What will it be made of? Will it be like us or something completely and utterly alien?

This is what I shall explore in upcoming posts.