It has been said several times that it is very selfish of humans to think that they are alone in this vast Universe. Not least because the Milky Way itself is full of habitable properties, with about half of all sun-like stars hosting Earth-sized worlds, worlds that can support life. There are over 300 million worlds with Earth-like conditions. So, what is the chance that there will be other civilizations and some are even dangerous to the point that there is a threat of attacking and invading Earth?
Alberto Caballero, a doctoral student in conflict resolution at the University of Vigo, estimates that there are four evil extraterrestrial civilizations in our galaxy.
First: believe that alien civilizations exist
One investigator stated that there may be four extraterrestrial civilizations in the Milky Way with the possibility of attacking or invading planet Earth. as reported by vice newsAlberto Caballero, who is a PhD student at the University of Vigo in Spain, estimated the prevalence of "malicious extraterrestrial" civilizations.
In the article titled "Estimating the Prevalence of Malicious Extraterrestrial Civilizations", Caballero attempted to provide an estimate of the prevalence of hostile extraterrestrial civilizations. Although, he admits that there are "some limitations".
Caballero noted that the estimate is based on "the world history of invasions over the past century, the military capabilities of the countries involved, and the global growth rate of energy consumption."
In their research, not yet peer-reviewed, published in Arxiv magazineCaballero stated that the upper bounds of standard deviations are used to obtain the "estimated probability of extraterrestrial invasion" by a civilization whose planet we sent a message.
The researcher also stated that the results show that such a probability is "two orders of magnitude lower than the probability of an asteroid impacting a planet".
Second: believing we can communicate with alien civilizations
Scientists are planning to send a message (METI, or "Messaging Extraterrestrial Intelligence") to the so-called alien civilization. While there is no definitive proof, the US government is taking the growing signs of extraterrestrial life seriously.
However, as a warning to scientists, Caballero said in his paper that the findings could serve as a starting point for an international debate about sending the first serious interstellar radio messages to nearby potentially habitable planets.
I played the role based solely on life as we know it. We do not know the mind of extraterrestrials. An extraterrestrial civilization may have a brain with a different chemical makeup and may lack empathy or may have more psychopathological behaviors.
I found this way to do it [o estudo]which has limitations because we don't know the mind of what aliens would be like.
Caballero told Vice.
Third: Believing that Earth is a target of malicious attack
In his article, he wrote that such event takes place once every 100 million years. Caballero has researched human "invasions" from other countries over the last 50 years, as he mentioned that he played the role based "only on life as we know it".
The report noted that he applied the data he collected to the number of known "exoplanets" in our galaxy. Claudio Maccone, a Italian scientist, estimated that there are about 15,785 exoplanets. After analyzing the data, Caballero estimated that there could be four "malicious" alien civilizations.
Caballero also authored a study in the International Journal of Astrobiology earlier this month. He claimed to have signaled the "WoW! Signal", first detected by a radio telescope in 1977. It was a strange, minute-long burst of radio energy. According to Caballero, the signal may have originated from a Sun-like star 1,800 light-years from Earth.
According to the publication, the signal was received for the first time by the big ear telescope at Ohio State University.