The Most Likely Way That Aliens Would Attack Us
Hollywood often depicts alien invasions as chaotic and apocalyptic. Who can forget the foreboding, heart-stopping sounds of the tripods in Steven Spielberg’s cinematic adaptation of H.G. Wells’ War of the Worlds, as they terrorized entire cities and vaporized frightened Earthlings with blazing lasers? And who didn’t enjoy watching fleets of fighter jets battling alien vessels in Independence Day after their enormous flying saucers blasted human landmarks to smithereens with ravenous firestorms?
The odds are good that Earth will never be attacked by extraterrestrials. After all, we haven’t even spotted any! Moreover, if an alien race were hostile, their likeliest form of assault would be nothing like in the movies. It would be far more subtle, but no less nefarious: a computer virus.
Astrophysicists Michael Hippke and John G. Learned considered this possibility in a paper published last year to the preprint server arXiv. Space is big, high-speed travel is difficult, and fleets of battleships are expensive, they reasoned, so the likeliest mode of attack for hypothetically malicious aliens would be code concealed in a message. Such code could contain an advanced A.I. that could sneak into computer systems and spread throughout the Internet, or a virus that would destabilize banking systems and electrical grids. Or perhaps, they suggested, an alien attack could simply be a panic-inducing prank, a statement like "We will make your sun go supernova tomorrow."
The only way to avoid this outcome is not to open a message from extraterrestrials, the cosmic equivalent of deleting a suspicious email.
"A message… cannot be decontaminated with certainty," Hippke and Learned cautioned. "For anything more complex than easily printable images or plain text, the technical risks are impossible to assess beforehand. We may only choose to destroy such a message, or take the risk. The risk for humanity may be small, but not zero."
Despite the danger, they still think we should read an alien message.
"Overall, we believe that the risk is very small, and the potential benefit very large, so that we strongly encourage to read an incoming message."