Oumuamua: “”if I’m right, this is one of the greatest discoveries in history””

Astrophysicist Avi Loeb explains in an interview to the Israeli newspaper Al Haaretz why it is believed that the strange asteroid Umuamua could be a spaceship of extraterrestrial origin.

“”I don’t care what people think””: Avi Loeb, Head of the astronomy department at Harvard University, doesn’t have the language in his pocket. Neither ideas : in an article published by “”The Astrophysical Journal Letters””, the discipline’s reference Journal, Avi Loeb speculates that the asteroid Umuamua, the first object observed in our solar system but not originating there, could have been manufactured by an extraterrestrial civilization.

In a major interview with the Israeli newspaper Al Haaretz, the astrophysicist, named by Time magazine as one of the 25 Most Influential People In Space Studies, persists : “”I wrote this article partly on the basis of discussions I had with colleagues whom I respect from a scientific point of view. These high-level personalities themselves say that this object has very particular characteristics. But they don’t dare report it publicly. I don’t understand this attitude.»

Lamenting the self-censorship of scientists who fear jeopardizing their reputation and their position, Avi Loeb prefers to try an almost pascalian bet : “”I may commit professional suicide if I am wrong. It’ll give me more time to do science. But, if I’m right, it’s one of the greatest discoveries in human history.

And the arguments put forward by the astrophysicist in support of his hypothesis weigh heavily : “”at first, everyone thought’ OK, it’s a comet’. But comets are made of ice that evaporates as they approach the sun. But Oumuamua did not leave behind any trail of dust or gas. So it must have been an asteroid, a simple piece of rock. But the object was rotated on its axis for eight hours. And during that time, its brightness changed by a factor of 10, while the changes in the brightness of the asteroids do not exceed a factor of 3. This means that its length is ten times its thickness.””This extreme geometry,”” continues Avi Loeb, “” can only be translated in two ways : either the object has the shape of a cigar, or it is flat as a pancake.””

But the most amazing surprise occurred last June when new data collected by the Hubble orbiting telescope showed that Oumuamua accelerated when it entered the Solar System, an acceleration that cannot be explained by the sun’s gravitational force alone. “”The other possibility would be the rocket effect that concerns comets : when one of them approaches the sun, its ice melts and escapes into space in the form of gas, which accelerates the comet like a rocket. But no such broadcasts have been detected. In addition, this loss of material would have affected the size and shape of the object, which was not found.»

For Avi Loeb, there is only one explanation : Oumuamua underwent an external push : “”it is an impulse caused by the solar radiation. But for this to work, the object must be very thin, less than a millimetre thick, in other words, it must have a crepe shape. Besides, we also know that it’s ten times brighter than a conventional asteroid. So we have a thin, flat, shiny object. So I’ve come to the conclusion that it could be a solar sail, a ship that uses the sun’s radiation to propel itself instead of fuel. And it’s a technology that our civilization is just beginning to develop.