Aliens probably exist – but there’s a terrifying reason why we’ve never met them

This summer, director Fede Alvarez ­returns the notorious Alien franchise to its monster-movie roots, and feeds yet another batch of hapless young space colonists to a nest of “xenomorphs”.

It remains to be seen if Alien: Romulus will do more than pay loving tribute to Ridley Scott’s original 1979 Alien, but it hardly matters – Alien is a franchise that survives despite the additions to its canon, rather than because of them. Even the worst sequels have failed to bankrupt its grim message, while the most visionary reimaginings have done nothing to alter it.

The original Alien is itself a scowling retread of 1974’s Dark Star, John Carpenter’s nihilist-­hippie debut, about an interstellar wrecking crew cast unimaginably far from home, bored to death and intermittently terrorised by a mischievous alien beach ball. Dan O’Bannon co-wrote both Dark Star and Alien, and inside every prehensile-jawed xeno­morph there’s an O’Bannonesque balloon critter snickering away.

O’Bannon’s cosmic joke goes something like this: we escaped the food chain on Earth, only to find ourselves at the bottom of an even bigger, more terrible food chain Out There among the stars. You don’t need an adventure in outer space to see the lesson. ­Carpenter went on to make The Thing (1982), in which intelligent and resourceful researchers on an Antarctic base are reduced to chum by one alien’s peckishness. You don’t even need an alien. Jaws dropped the good folk of Amity Island NY back into the food chain, and that pre-dated Alien by four years.

Alien, according to O’Bannon’s famous pitch line, was “Like Jaws in space”, but by moving the action beyond our planet, it added a whole new level of existential dread. Alien shows us that if nature is red in tooth and claw here on Earth, then chances are it will be so up there, too. The heavens cannot possibly be heavenly: now, here was an idea calculated to strike fear into fans of 1982’s ET the Extra-Terrestrial.

In ET, intelligence counts – the visiting alien is benign because it is a space traveller. Any species smart enough to travel among the stars is also smart enough not to go around gobbling up the neighbours. Indeed, the whole point of space travel turns out to be botany and gardening.

Ridley Scott’s later Alien outings, Prometheus (2012) and Covenant (2017), are, in their turn, muddled counter-arguments to ET; in them, cosmic gardeners called Engineers gleefully spread an invasive species (a black xenomorph-inducing dust) across the cosmos.

“But, for the love of God – why?” cry ET fans, their big, trusting kitten eyes tearing up at all this inter­stellar mayhem. And they have a point. Violence makes evolutionary sense when you have to compete over limited resources. The moment you journey among the stars, though, the resources avail­able to you become infinite. In space, assuming you can navigate comfortably through it, there is no point in being hostile.

If the prospect of interstellar life has provided the perfect conditions for numerous Hollywood blockbusters, then the real-life hunt for aliens has yielded more mixed results. When Paris’s Exposition Universelle opened in 1900, it was full of wonders: the world’s largest telescope; a 148ft-diameter ­“Cosmorama” (a restaurant and planetarium); and the announcement of a prize, offered by the socialite Clara Guzman: 100,000 francs (£500,000 in today’s money), to be awarded to the first person to contact an extraterrestrial species.

By 1900, extraterrestrials were no longer a strange idea. The habit­ability of other worlds had been ­discussed seriously for centuries, and proposals on how to communicate with other planets were mounting up: these projects involved everything from mirrors to earthworks visible from space.

What is striking is the exclusion clause written into the prize’s small print. Communicating with Mars wouldn’t win you anything, since links with Mars were already being established. Radio pioneers Nikola Tesla and Guglielmo Marconi would both go on to say they had received signals from outer space. Percival Lowell, a brilliant astronomer working at the very limits of optical science, claimed to have found gigantic irrigation works on the red planet’s surface: in his 1894 book, he published clear visual evidence of Martian civilisation.

Half a century later, our ideas about aliens had changed. Further study of Mars and Venus had shown them to be lifeless, or as good as. Meanwhile, the cosmos had turned out to be exponentially larger than anyone had thought in 1900. Larger – but still utterly silent.

In the summer of 1950, during a lunchtime conversation with his colleagues Edward Teller, Herbert York and Emil Konopinski, at Los Alamos National Laboratory, in New Mexico, the Italian-American physicist Enrico Fermi gave voice to the problem: “Where is everybody?”

The galaxy is old enough that other intelligent species capable of interstellar travel could have visited every star system many times over. Time enough has passed for galactic empires to rise and fall. And yet, when we look up, we find absolutely no evidence for them.

We started our hunt for alien civilisations using radio telescopes in the 1960s. Our perfectly reasonable attitude was: if we are here, why shouldn’t they be there? The possibilities for life in the cosmos bloomed all around us. We found that almost all stars have planets, and most have rocky planets orbiting the habitable zone around the star. Water is everywhere: there are several alien oceans we know of just in our own solar system. On Earth, microbes have been found that can withstand the rigours of outer space. The impacts of large meteor strikes have no doubt propelled them into space from time to time. Even now, some of the hardier varieties may be flourishing in odd corners of Mars.

All of which makes the cosmic silence still more troubling.

Maybe ET just isn’t interested in us. You can see why. Space travel has proved a lot more difficult to achieve than we expected, and unimaginably more expensive. Visit­ing even very near neighbours is next to impossible. Space is big, and it’s hard to see how journey times, even to our nearest planets, wouldn’t destroy a living crew.

Travel between star systems is a whole other order of impossible. Even allowing for the series’ dodgy physics, it remains an inconvenient truth that every time Star Trek’s USS Enterprise hops between star systems, the energy required has to come from somewhere. Is the United Federation of Planets dismantling, refining and extinguishing whole moons?

Life, even intelligent life, may be common throughout the universe – but then, each instance of it must live and die in isolation. The distances between stars are so great that even radio communication is impractical. Civilisations are high-energy phenomena, and all high-energy phenomena burn out quickly. By the time we receive a possible signal from an extraterrestrial civilisation, that civilisation will most likely already be dead.

It gets worse. The universe ­creates different kinds of suns as it ages. Suns like our own are an old model, and they’re already blinking out. Life like ours has had its heyday in the cosmos, and one very likely answer to the question “Where is everybody?” is “You came too late to the party.”

Others have posited even more disturbing theories for the silence. Cixin Liu is a Chinese science-­fiction novelist whose Hugo Award-winning The Three-Body Problem (2008) recently teleported to Net­flix. According to Liu’s notion of the cosmos as a “dark forest”, space­faring species are by definition so technologically advanced, no mere planet could mount a defence against them. Better to keep silent: there may be wolves out there, and the longer our neighbouring star systems stay silent, the more likely it is that the wolves are near.

The Russian rocket pioneer Konstantin Tsiolkovsky, who was puzzling over our silent skies a couple of decades before Fermi, was more optimistic. Spacefaring civilisations are all around us, he said, and (pre-figuring ET) they are gardening the cosmos. They will no more communicate with us, in our fragile, planet-bound state, than Spielberg’s extraterrestrial would tread on a newly discovered caterpillar.

But this is a vision of alien life that shows unlikely self-restraint. The trouble with intelligent beings is that they are incapable of leaving things alone.

The late-20th-century Soviet ­science-fiction novelists and brothers Arkady and Boris Strugatsky argued that the sole point of life for a spacefaring species would be to see to the universe’s well-being by nurturing sentience, consciousness, and even happiness.

To which Puppen, one of their most engaging alien protagonists, grumbles: Yes, but what sort of consciousness? What sort of happiness? In their 1985 novel The Waves Extinguish the Wind, Toivo Glumov, an alien-chaser, complains, “No­body believes that the Wanderers intend to do us harm. That is indeed extremely unlikely. It’s something else that scares us! We’re afraid that they will come and do good, as they understand it!” Fear, above all enemies, the ones who think they’re doing you a favour.

In the Strugatskys’ wonderfully paranoid Noon Universe stories, the aliens already walk among us, nudging us towards their idea of the good life. Maybe they do. How would we know, either way? The way I see it, alien investigators might even now be quietly mowing their lawns in, say, Slough. They live, laugh and love like humans; they even die like humans. In their spare time, they write exquisite short stories about the vagaries of the human condition, and it hasn’t once occurred to them (thanks to their memory blocks) that they’re actually delivering vital strategic intelligence to a mothership hiding behind the Moon.

You can pooh-pooh my little fantasy all you want; I defy you to disprove it. That’s the problem. Aliens can’t be discussed scientifically. They’re not a merely physical phen­o­menon whose abstract existence can be proved or disproved through observation. They’re like us: clever, elusive, and unpredictable.

The Polish writer Stanislaw Lem had a spectacularly bleak solution to Fermi’s question, best articulated in his 1986 novel Fiasco. By the time a civilisation is in a position to communicate with others, he argued, it’s already become hopelessly self-involved. At best, its individuals will be living in ­simulations; at worst, they will be fighting pyrrhic, planet-busting wars against their own shadows. In Fiasco, the crew of the Eurydice discover, too late, that they’re just as fatally self-obsessed as the aliens they encounter.

We see the world through our own peculiar evolutionary perspective. This gives us a very narrow idea of what life looks like. We out-competed our evolutionary cousins long ago, and for the whole of our recorded history, we’ve been the only species we know that sports anything like our kind of intelligence. Our long loneliness may have sent us slightly mad. Because of that, we’re not equipped to meet aliens – only mirrors. Only angels. Only monsters.

And Alien: Romulus’s xenomorphs are, worse luck, most likely in the same bind.

Alien: Romulus is in cinemas from August 16

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