Recent advances in science and technology have allowed alien hunters to scour the far reaches of space for any signs of alien life. Although we have yet to identify any evidence of extraterrestrial life, either microbial or intelligent, some scientists believe that there may be a potential threat to humanity from aliens.

In a new research paper, astrophysicists Michael Hippke and John Learned argue that telescopes designed to search for alien signals, could pick hazardous messages from intelligent extraterrestrials. According to the researchers, aliens could launch a virus or cyberattacks to shut down our computer systems.

The researchers also suggested that aliens could "gift" us with an artificial intelligence (AI) system that may trick humans into developing self-replicating nanobots and eventually deploy them to wreak havoc on our planet. The researchers argue that it would be cheaper for aliens to "send a malicious message to eradicate humans compared to sending battleships".

In one scenario, the researchers argued that a message from aliens could be a panic-inducing statement like "We will make your sun go supernova tomorrow". According to the researchers, if such a threatening message is received in just one location, it may be possible to contain and even destroy it. "If it is received repeatedly, perhaps even by amateurs, containment is impossible," the researchers wrote in a paper available online on arXiv.

In another scenario, the scientists argue that humans could be tricked into begetting their own demise by aliens offering the "gift" of knowledge. For instance, aliens could transmit a message that reads: "We are friends. The galactic library is attached. It is in the form of an artificial intelligence (AI) which quickly learns your language and will answer your questions. You may execute the code following these instructions..."

In this scenario, the researchers suggest that even if the utmost care is taken to isolate the AI – by flying the system to the moon and wiring it up with explosives so it can be shut down immediately in the event of a threat, the AI would still likely have some human contact.

"Even in a military-style, adamant experiment, there will still be humans involved who go home after examination work with their own feelings. Even if everything is officially secret, whistle-blowers might get some news out to the public," the researchers wrote. "Quickly, there could be a community on Earth in favor of letting it out for religious, philosophical etc. reasons.

"If the AI promises to cure cancer, or offers a message of salvation, a cult could form. Maybe (or maybe not) a majority of the population would be in favor of releasing the AI. Should, or even could, a democratic government work against the majority of its people? Dictatorships are unstable and eventually overthrown; the AI will be eventually released. Then, the worst possible result would be human extinction or some other unrecoverable global catastrophe."

The scientists warn that in the event we receive any complex messages from extraterrestrial life forms, they should be destroyed to avoid a potential threat.

But is it even likely that we would receive messages from an alien civilisation in a language that we understand?

"In movies, extraterrestrials often communicate with us in colloquial English. But a real message from space is likely to be no more understandable than a digital TV signal would be to Guglielmo Marconi," Seth Shostak, an astronomer at the SETI Institute, wrote in an op-ed in NBC News. "An alien transmission is unlikely to be a Trojan horse — but it would at least tell us that there's someone outside the gates."

Scientific reasons people might believe in aliens iStock