In the Headlines | Harvard professor considers extraterrestrial probe

Harvard University's director of astronomy, Avi Loeb, has caused a small earthquake in the scientific world. In a scientific journal ("The Astrophysical Journal Letters") he seriously considers the asteroid Oumuamua as an extraterrestrial probe. On Wednesday, the Israeli daily Haaretz published a lengthy interview with the scientist who explains the basics of his reasoning (read in English).

The journalist likes to see such a prestigious professor put his credibility at risk with such an idea. "Maybe I'm committing suicide professionally [...] concedes the scientist, before listing the prestigious caps he puts on the line. But if that's true, it's one of the greatest discoveries in human history. "

The "far-off messenger"

The discovery of Oumuamua is already a first, which has moved the scientific community. His name means "distant messenger" in Hawaiian (he was first seen by the Pan-STARRS1 telescope of Hawaii on October 19, 2017) since his characteristics immediately proved to the observers that this object did not come from our system solar.

"If you're not ready to find great things, you will not find them," recalls Avi Loeb. But Oumuamua's size, speed and movement have been questioning scientists since the beginning. But last June, it was determined that the object had accelerated at some point in its trajectory - it passed relatively close to the Sun and the Earth. "The only hypothesis I could think of," he says, "is a surge in the pressure of solar radiation. For this to work, the object should be very thin, less than a millimeter thick [...] So I came to the idea of ​​a solar sail: a solar sail is a spaceship that uses the sun to propel itself [...] In fact, it is a technology that our civilization is developing right now. "