PARIS | In 2017, the passage of a strange bolide in our solar system put astronomers in turmoil, to the point that some saw it as the signal of extraterrestrial life. A controversial thesis but that a recognized scientist, Avi Loeb, still defends, in an essay published Thursday with a worldwide release.
“If I’m right, it’s the greatest discovery in human history,” warns Avi Loeb, director of the astronomy department at Harvard University, in the red advertising banner posed by his editor French, Le Seuil.
In “The first sign of intelligent extraterrestrial life”, this black hole specialist looks back on the detection of Oumuamua, a cigar-shaped object that crossed our solar system at full speed, in October 2017.
Spotted by the Pan-STARRS1 telescope in Hawaii, Oumuamua – which means “messenger” in Hawaiian – measured 400 meters in length and 40 meters in width. Its speed was so high that it could only come from a distant star: it was the first object detected coming from another star system.
After being described as an asteroid, a team from the European Space Agency estimated that it was more likely a comet ejected from another star system.
But the hypothesis left Avi Loeb unsatisfied. Because according to him, it did not allow to explain the excessive acceleration of the thing, nor the fact that it did not release any trail (gas or dust) while passing near the Sun, nor its unusual shape.
With another Harvard researcher, he signed an article in the journal Astrophysical Journal Letters, advancing the theory that Oumuamua could only be a probe propelled by an extraterrestrial civilization.
Their publication was strongly criticized. Today, writes Avi Loeb, “the debate continues for lack of tangible evidence” and “whatever one ends up concluding about Oumuamua, it is clear that it was, and remains, an anomaly in itself. “.
In 272 pages, the American-Israeli physicist sets out his hypotheses on “this first interstellar visitor ever identified”, and “explores the question of whether we are alone in the Universe”, explain the editions of Le Seuil.
He particularly regrets “the opprobrium cast” at the university on questions relating to SETI, an institute bringing together research projects for extraterrestrial intelligence, based in California. And pleads for broadening the field of research, beyond the quest for microbial life on Mars, the objective of NASA’s Perseverance mission, which is due to land on the red planet on February 18.