I鈥檓 not saying it鈥檚 aliens, but鈥� No, I鈥檓 just not saying it鈥檚 aliens, full stop. It is never aliens. Reports of a strong radio signal picked up by Russian astronomers observing the distant star HD 164595 sent the internet into a frenzy this week. It has now been confirmed as a terrestrial source, perhaps a previously unlisted 鈥� more spy-fi than sci-fi.
The incident is the latest in a seemingly endless string of potential discoveries of aliens, including Proxima b, Tabby鈥檚 star and Planet Nine, that have driven a resurgence of interest in SETI not seen since the heady days of ufology, Contact and The X-Files in the 1990s.
Like Fox Mulder, we desperately want to believe that aliens are out there. In recent years, this desire has been legitimised by the rise of the exoplanet, one of the most exciting scientific fields around today. When The X-Files first aired in 1993, astronomers had only just made the first tentative claims of planets outside the solar system. When the series returned to our screens earlier this year, astronomers could boast thousands of discoveries, suggesting a universe filled with billions upon billions of worlds, far more than anyone had imagined.
Advertisement
Ample rolls of the dice
The majority of these discoveries are little more than tiny blips on a telescope, about which we know almost nothing, but our imagination can easily transform them into actual, physical places.
Given such vast planetary real estate, aliens must be dwelling somewhere, right?
Although we don鈥檛 know enough about the origin of life to say for sure, it is almost certain that aliens have arisen from the primordial goo elsewhere. Even if the odds of life are incredibly low, a universe 93 billion light years wide provides ample rolls of the dice to get things started. For Earth to be the sole flame of light in the darkness suggests some kind of outside influence, whether a supreme being or the reality that we live in an artificial simulation. Aliens are far, far more likely.
Many stars to align
And yet, the vastness that conjures aliens into being also prevents us from making contact. at the SETI Institute in Mountain View, California, calculated that if the Russian signal had been real, aliens at HD 164595 would have needed to consume an entire sun to provide enough energy for it to reach us, assuming they beamed it in all directions. If the message was specifically directed at us, that energy requirement drops to 鈥渙nly鈥� the entire historical power consumption of humanity.
HD 164595 is 95 light years from Earth. A back-of-the-envelope calculation suggests any aliens dwelling there will see our sun as just one of 14,000 other stars at the same distance or less. Are we arrogant enough to think our pin-prick of light is worth bothering to contact, when there are so many other options to choose from? Earth just isn鈥檛 that special.
The enormity of the universe doesn鈥檛 extend only into space. It鈥檚 14 billion years since the universe began, but we Earthlings have been capable of interstellar communication for only the past hundred years, if we鈥檙e being generous, and who knows how much longer we鈥檒l be around. If aliens are also communicating only for such a short window of time, we are likely to miss them.
Smell them out
Of course, the chance is always there, and that鈥檚 why it makes sense to listen, even if people at the SETI Institute and elsewhere might ultimately be devoting their lives to a fruitless search. But rather than expecting messages from outer space, or flying saucers landing on the White House lawn, we need to accept that the aliens aren鈥檛 going to come to us.
Instead, our best chance of confirming that we aren鈥檛 alone comes from the kind of painstaking observations that led to the discovery of those thousands of exoplanets. In a decade or so, the next generation of massive telescopes will let us remotely sniff the atmospheres of these worlds, looking for signs of molecules like oxygen, methane and water that could point to a biological origin.
Even then, I won鈥檛 be saying it鈥檚 aliens. There could be geological explanations for gases, or they might be in concentrations too low to support life, so astronomers are likely to spend another decade arguing about what could be responsible, carefully modelling and ruling out all the options.
Alien AI
And after all that, all we could confidently say is there might be some kind of life 鈥� probably microbial 鈥� clinging to the rocks of a far-off land. It would be an incredible, transformative discovery, finally confirming that the process that gave life to everything on Earth is also operating elsewhere in the universe.
If you鈥檙e still hoping for a sci-fi future 鈥� newsflashes of a huge spacecraft looming up behind <insert your favourite world monument here> 鈥� I鈥檓 sorry to pour cold water on your imagination.
But here鈥檚 a bone. There is just one possibility for alien visitors that I鈥檓 willing to entertain 鈥� a sentient, self-replicating artificial intelligence that has been sent out by its creators to explore the stars and communicate with any civilisation it encounters.
Assuming sufficiently advanced technology, such an entity would be able to endure the thousands of years of travel required to come and have a chat. But would we even understand what it was saying? These things would essentially be , which, as anyone who saw the last half hour of that movie would attest, means they are likely to be incomprehensible. Still, at least we鈥檇 have made first contact, if only with an alien鈥檚 answer phone.
