The extraterrestrial hypothesis is not decidedly unanimous. Oumuamua, a cigar-shaped machine spotted in 2017 during its crossing of the solar system, could perhaps possibly have been sent by extraterrestrials, suggested two Harvard researchers in a scientific article. They have been strongly criticized by the scientific community.
Oumuamua was spotted by the Pan-STARRS1 telescope in Hawaii, hence its name, which means "messenger" in Hawaiian. It is about 400 meters long and 40 wide, and has been tracked by several telescopes as the first detected object from another star system. After being described as an asteroid, a team of the European Space Agency estimated in June that it was more likely a comet (with ice that turns into gas near the Sun).
No, 'Oumuamua is probably not an alien spaceship https://t.co/SDEbcezrwp pic.twitter.com/Liktf3d8JU
– Gizmodo (@Gizmodo) November 6, 2018
An "exotic scenario", in the words of the authors of the new article, would be that "Oumuamua could be a fully operational probe sent voluntarily near the Earth by an extraterrestrial civilization," they write in an article to be published on November 12 in the journal Astrophysical Journal Letters. The idea quickly ignited Twitter and the scientific community.
"Numbers that contain a lot of uncertainty"
The reason for this assumption is that Oumuamua moves at a faster rate than expected. The excessive acceleration could be explained by the pressure of solar radiation, or "solar veil". But according to the two researchers, Harvard, this is only possible for heavenly bodies "that have a large surface and are very thin, which does not exist in nature." Hence the recourse to another explanation: it is a propelled probe.
But scientists had rejected this theory shortly after the discovery. No artificial signals were found from the body. "Like many researchers, I would very much like that there is irrefutable evidence of extraterrestrial life, but that is not the case," Alan Fitzsimmons, an astronomer at Queens University in Belfast, told AFP on Tuesday. "It has already been shown that the observed characteristics of the object are consistent with those of a comet-like body ejected from another star system," he says. He adds: "Some of the arguments in their study are based on numbers that contain a lot of uncertainty."
So if you come with something in the category of "not * obviously * wrong and also HUGE IF TRUE," the chance that it will be backfire is small, and the low-probability high-reward payoff might be tempting enough to make it worth looking at the eye-rolls of your colleagues.
– Katie Mack (@AstroKatie) November 6, 2018
Katie Mack, an astrophysicist at North Carolina State University, also disagrees. "You have to understand that for scientists, the craziest idea is always publishable, as long as there is a tiny chance that it is not wrong," she wrote on Twitter. "Even the authors probably do not believe it themselves."
We could never know
"I would not say that I" believe "that he was sent by extraterrestrials," says Shmuel Bialy, a postdoctoral astrophysicist at Harvard. "Because I am a scientist, not a believer. I rely on evidence to find possible physical explanations for observed phenomena. "
The other author, Avi Loeb, head of the Harvard Astronomy Department, told NBC that humanity may never know because Oumuamua is moving away from Earth and will not be coming back. "It is impossible to guess the purpose of Oumuamua without more data."