“We have proof that there are alien civilizations,” says astrophysicist Avi Loeb
Are we alone? This is probably the most profound question that still faces humanity today. What if the answer to this question is no? Would we be ready to accept it? For Avi Loeb, an astrophysicist at Harvard University (United States), extraterrestrial technology has recently crossed our Solar System. He explains to us how he arrived at this conclusion.
October 2017. An observatory in Hawaii (United States) reports the observation of a mysterious object which passes through our Solar System at a speed about four times that of most asteroids. The object follows a hyperbolic trajectory which indicates to astronomers that it comes from elsewhere. It is baptized 1I / 2017 U1. And quickly nicknamed ‘Oumuamua, understand “the guest”, “the messenger”. It awakens all curiosities. “‘Oumuamua dazzles scientists”, then headlines NASA. Because it is the very first interstellar object observed so close to Earth. But also because it presents a certain number of surprisingly surprising characteristics.
Comet, asteroid, fragment of celestial body. Over the months, all the assumptions about its nature have been put on the table. Including the craziest of all: that of the alien ship! A hypothesis supported – against and against almost everyone – by Abraham Loeb, president of the department of astronomy at Harvard University (United States). “The scientific method encourages caution. We make a hypothesis, collect evidence and test that hypothesis. Then we refine the hypothesis or gather more evidence. But fashions can discourage the consideration of certain assumptions and careerism can direct attention and resources to certain topics and distance them from others, ”he explains.
“Personally, I am convinced that ‘Oumuamua is the proof that there is or that there have been sensitive civilizations other than ours, elsewhere in the Universe. And I would like the community to agree to give my theory as much credit as it gives the supersymmetry or multiverse hypothesis. But I also believe that humanity is not ready to accept that we are not unique. “
`Oumuamua, a strangely shaped interstellar object
But what does Avi Loeb base his hypothesis on? On a few singularities noted by researchers who studied the interstellar object. Its shape first. “We have no clear image of the object. Only the data from eleven days of observations – before the object moved too far from Earth – by several telescopes, says Avi Loeb. They show that the luminosity of ‘Oumuamua varies by a factor of ten every eight hours. »What concludes that the object is much longer than wide. Some first spoke of cigar shape. Then the data shifted, statistically much more likely, to some form of disk.
“Anyway, we have never observed in nature, such flat and / or elongated object, assures us Avi Loeb. And that’s not to mention the fact that ‘Oumuamua was also at least ten times brighter than any asteroid or comet of similar size. A number of explanations have been put forward.
A trajectory that defies the laws of physics
“If it had been just that, I would have moved on,” says Avi Loeb. But there was also the trajectory anomaly that appears in the data collected by astronomers. According to the researcher from Harvard University, it is “breathtaking”. “The laws of physics allow us to predict the trajectory of an object subjected to the gravitational influence of the Sun. But ‘Oumuamua did not behave as expected. At a distance from our star, he saw himself as being pushed by a mysterious force. “It happens to comets too. A sort of “rocket engine” effect that they owe to their long tail of evaporating ice. “
For this rocket effect to explain the deviation of ‘Oumuamua’s trajectory, the object would have had to lose a tenth of its mass. However, on scanning the surrounding space, astronomers found no trace of water, gas or dust.
Other hypotheses have been put forward. First, that of a collision with another object. But the data didn’t match. Then that the ice carried by the interstellar object was exclusively composed of hydrogen. But the idea didn’t last very long. That of the action of the radiation pressure of the Sun has also been investigated. But it would involve an incredibly low mass density. Only 1% of that of the air on the Earth’s surface. Enough to make ‘Oumuamua the most porous object ever observed in our Solar System.
`Oumuamua, an Alien Spaceship?
“To me, ‘Oumuamua is so unlike anything else we know in the Universe that it must have been designed, built and launched by alien intelligence. Maybe a veil floating in space. A communication buoy. Or a piece of debris abandoned by a civilization other than ours, Avi Loeb argues. I realize this is an exotic hypothesis. But the other hypotheses put forward to explain these particular characteristics are no less so. None can really explain the trajectory of ‘Oumuamua. And yet, the object has deviated ”, does not hesitate to launch the researcher in a nod to Galileo.
” Let’s be clear. I am not one of those looking for the spotlight. I’m just asking myself questions. By trying not to let myself be overwhelmed by prejudices. “