October 21, 2021

I, Science

The science magazine of Imperial College

Forget your UFO hunting and exoplanet probes; why we shouldn’t be searching for alien life at all ...


Science fiction has conjured up a plethora of fictional alien species, from the harmless likes of E.T. to the positively barbaric xenomorphs of the Alien series. The possibility of life existing outside of Earth, especially intelligent life, has fascinated both scientists and non-scientists for generations. But, should we really be searching for it?

Whilst there’s not yet definite proof that life exists outside of Earth it’s almost a mathematical certainty. It has been estimated that there are more than 170 billion galaxies in the observable Universe. Given the millions and billions of stars and planets contained within each one it’s more likely than not that some form of life exists in a far-flung galaxy.

It has been claimed by many, including theoretical physicist Stephen Hawking, that searching for intelligent life is a dangerous endeavour. The argument goes that any species finding us or being alerted to our presence would arrive to plunder our planet for resources, be they mineral, organic or human. Or maybe they’d pop over just to wipe us out, Independence Day style. But why would they bother?

Earth is no longer a goldmine of resources. Humankind is accepting that Earth’s natural resources are in decline, and we’re looking out to space to meet our needs, through asteroid strip-mining for example. An alien ‘resource acquisition team’ would probably mark Earth as ‘spent’, especially considering the vast number of other, resource-laden planets and celestial bodies in the Universe. Any species capable of crossing the vast distances of space and time to find us would have solved any resource issues they had long ago, and would hardly need what Earth has to offer.

If anything, contacting intelligent life elsewhere would be a pointless endeavour. We share a common genetic structure and building block (carbon) with all other Earth-bound organisms, and yet we can only converse intelligibly with other members of our species. Chimpanzees, our closest living relatives, share approximately 95-99% identical DNA with us; that mere 1-5% difference is enough to split us apart and account for our differences and accomplishments. Chimpanzees, to our knowledge, have not landed on the Moon.

This raises a thought-provoking question: if we cannot meaningfully communicate with chimpanzees, organisms whose DNA differs from ours by as little as 1%, what is the likelihood intelligent life, having developed on a completely different planet under potentially radically different conditions, would be able to relate to us in any way, shape or form? The answer is probably way below 1%.

So where does this leave us? Practically speaking, alone. Searching for intelligent life is a waste of time and resources, both of which could be far better spent elsewhere. We can’t rely on a superior alien species to swoop down and fix up all our problems – that’s our job. If we can do that, maybe we’ll be the ones swooping down on worlds unknown.


IMAGE: bradhallart, flickr