‘Stephen Hawking famously said sending messages from Earth into deep space could get human civilization destroyed: “If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn’t turn out very well for the Native Americans.”

Hawking’s words have often been used to discourage the practice of METI, which is Messaging Extraterrestrial Intelligence. But how many “malicious” alien civilizations are there? And what are the chances any message we sent into our own galaxy would be received by an evil alien civilization? There is precious little research on this topic, and very few scientists have even posited a guess.

A new thought experiment attempts to at least venture a guess in hopes that other scientists will begin to take METI more seriously, and will try to determine how dangerous it actually is to try to contact alien civilizations.

According to this paper, which the author admits has “some limitations,” there are roughly four “malicious extraterrestrial civilizations” in the Milky Way, and we could likely send out 18,000 interstellar messages to different exoplanets in our galaxy and the probability of ensuring our own destruction would still be about the same as Earth being hit by a “global catastrophe asteroid.”…’ (VICE)