There may be four extraterrestrial civilizations in the Milky Way that could attack our planet, a researcher has claimed.
Alberto Caballero, a PhD student at the University of Vigo in Spain, authored a study in the International Journal of Astrobiology earlier this month in which he claimed that he pinpointed the so-called “WoW! Signal.”
The signal, which was first detected by a radio telescope in 1977, was a strange minute-long burst of radio energy that may have originated from a Sun-like star 1,800 lightyears from the Earth, according to Caballero.
It was first received by the Big Ear telescope at Ohio State University and is considered the best candidate signal of extraterrestrial life since humans began searching more than 60 years ago, Vice News reported.
Caballero’s paper, which is titled “Estimating the Prevalence of Malicious Extraterrestrial Civilizations,” has “some limitations,” the author admitted.
Caballero’s research has not been peer-reviewed by other astronomers, and the paper is considered to be more of a “thought experiment.”
He warned scientists to use caution in using the practice of METI, or “Messaging Extraterrestrial Intelligence” for fear it could provoke an alien invasion.
But Caballero conceded that the odds of extraterrestrials wiping out the human species is about the same as the planet being destroyed by a “global catastrophe asteroid.”
He wrote that such an event takes place once every 100 million years, so humans are in all likelihood safe for the time being.
In putting together the study, Caballero researched human “invasions” of other countries over the last 50 years.
He then used that data and applied it to the number of known “exoplanets” in our galaxy, which Italian scientist Claudio Maccone estimated to be around 15,785.
Using the frequency of human conflict — which has decreased in the last half century as technology has advanced — and applying the math to outer space, Caballero estimates that there could be four “malicious” alien civilizations.
“I did the paper based only on life as we know it,” Caballero told Vice.
“We don’t know the mind of extraterrestrials. An extraterrestrial civilization may have a brain with a different chemical composition and they might not have our empathy or they might have more psychopathological behaviors,” he said.
“I found this way to do [the study], which has limitations, because we don’t know the mind of what aliens would be like.”
The US government has in recent months taken seriously increasing signs of extraterrestrial life, though there is still no definitive proof.
An interim report released by intelligence officials last year counted 144 sightings of aircraft or other devices apparently flying at mysterious speeds or trajectories.
In all but one of the sightings investigated, there was too little information for investigators to even broadly characterize the nature of the incident.
