Humans have invented a rogue’s gallery of nightmarish fictional aliens over the decades: acid-blooded xenomorphs who want to eat us and lay their eggs in our chest cavities; Twilight Zone Kanamits who want to fatten us up like cows and eat us; those lizard creatures in the 1980s miniseries V who want to harvest us for food. (You may be sensing a theme here.)
But the most frightening vision isn’t an alien being at all — it’s a computer program.
In the 1961 sci-fi drama A for Andromeda, written by the British cosmologist Fred Hoyle, a group of scientists running a radio telescope receive a signal originating from the Andromeda Nebula in outer space. They realize the message contains blueprints for the development of a highly advanced computer that generates a living organism called Andromeda.
Andromeda is quickly co-opted by the military for its technological skills, but the scientists discover that its true purpose — and that of the computer and the original signal from space — is to subjugate humanity and prepare the way for alien colonization.
No one gets eaten in A for Andromeda, but it’s chilling precisely because it outlines a scenario that some scientists believe could represent a real existential threat from outer space, one that takes advantage of the very curiosity that leads us to look to the stars. If highly advanced aliens really wanted to conquer Earth, the most effective way likely wouldn’t be through fleets of warships crossing the stellar vastness. It would be through information that could be sent far faster. Call it “cosmic malware.”
To discuss the possibility of alien life seriously is to embark upon an uncharted sea of hypotheses. Personally, I fall on the Agent Scully end of the alien believer spectrum. The revelation of intelligent extraterrestrials would be an extraordinary event, and as SETI pioneer Carl Sagan himself once said, “extraordinary claims require extraordinary evidence.”
Intelligent extraterrestrials who also want to hack our planet would be even more extraordinary. But this scenario became a bit easier to envision this week.
On Wednesday, a story published in China’s state-backed Science and Technology Daily reported that the country’s giant Sky Eye radio telescope had picked up unusual signals from space. According to the piece, which cited the head of an extraterrestrial civilization search team that was launched in China in 2020, narrowband electromagnetic signals detected by the telescope differed from previous signals, and were in the process of being investigated.
The story was apparently deleted from the internet for unknown reasons, though not before it was picked up by other outlets. At this point it’s difficult to know what, if anything, to make of the story or its disappearance. It wouldn’t be the first time an extraterrestrial search team found a signal that appeared notable, only to dismiss it after further research. But the news is a reminder that there is little in the way of clear agreement about how the world should handle an authenticated message from an apparent alien civilization, or whether it can even be done safely.
For all the recent interest in UFO sightings — including NASA’s surprising announcement last week that it would launch a study team to investigate what it calls “unidentified aerial phenomena” — the chance that aliens would be physically visiting Earth is vanishingly small. The reason is simple: Space is big. Like, really, really, really big. And the idea that after decades of searching for ET with no success, there could be alien civilizations capable of crossing interstellar distances and showing up on our planetary doorstep beggars belief.
But transmitting gigabytes of data across those vast interstellar distances would be comparatively easy. After all, human beings have been doing a variation of that for decades through what is known as active messaging.
In 1974, the astronomer Frank Drake used the Arecibo Observatory in Puerto Rico to blast 168 seconds of two-tone sound toward the star system M13. It sounded like noise, but any aliens listening might have noticed a clear, repetitive structure indicating its origin was non-natural — precisely the kind of signal that radio telescopes like China’s Sky Eye are listening for here on Earth.
Such active messaging efforts were controversial from the start. Beyond the debate about who exactly should get to decide on behalf of the Earth when we try to say “hello” to aliens and what that message should be, transmitting our existence and location to unknown denizens of the cosmos could be inherently dangerous.
“For all we know,” wrote then-Astronomer Royal Martin Ryle shortly after the Arecibo message, “any creatures out there might be malevolent — and hungry.”
Those concerns haven’t put an end to efforts to actively signal to alien civilizations that are “very likely to be older and more technologically advanced than we are,” as Sigal Samuel wrote in a 2019 story about a crowdsourced contest to update the Arecibo message. But we shouldn’t be so sure that simply listening quietly for messages from space is a safer method of extraterrestrial discovery.
In a 2012 paper, the Russian transhumanist Alexey Turchin described what he called “global catastrophic risks of finding an extraterrestrial AI message” during the search for intelligent life. The scenario unfolds similarly to the plot of A for Andromeda. An alien civilization creates a signal beacon in space of clearly non-natural origin that draws our attention. A nearby radio transmitter sends a message containing instructions for how to build an impossibly advanced computer that could create an alien AI.
The result is a phishing attempt on a cosmic scale. Just like a malware attack that takes over a user’s computer, the advanced alien AI could quickly take over the Earth’s infrastructure — and us with it. (Others in the broader existential risk community have raised similar concerns that hostile aliens could target us with malicious information.)
What can we do to protect ourselves? Well, we could simply choose not to build the alien computer. But Turchin assumes that the message would also contain “bait” in the form of promises that the computer could, for example, solve our biggest existential challenges or provide unlimited power to those who control it.
Geopolitics would play a role as well. Just as international competition has led nations in the past to embrace dangerous technologies — like nuclear weapons — out of fear that their adversaries would do so first, the same could happen again in the event of a message from space. How confident would policymakers in Washington be that China would safely handle such a signal if it received one first — or vice versa?
As existential risks go, cosmic malware doesn’t compare to out-of-control climate change or engineered pandemics. Someone or something would have to be out there to send that malicious message, and the more exoplanets we discover that could plausibly support life, the odder it is that we have yet to see any concrete evidence of that life.
One day in 1950, at the Los Alamos National Laboratory, the physicist Enrico Fermi posed a question to his lunch companions. Given the vast size and age of the universe, which should have allowed plenty of room and time for alien life to arise, why haven’t we seen them? In other words: “Where is everybody?”
Scientists have posited dozens of answers to his question, which became known as the “Fermi paradox.” But perhaps the right answer is the simplest one: No one’s home. It would be a lonely answer, but at least it would be a safe one.
A version of this story was initially published in the Future Perfect newsletter. Sign up here to subscribe!