Other experts in his orbit would like him to just shut up about it, but Avi Loeb, chairman of Harvard University's astronomy department, remains insistent a piece of an alien spacecraft has been observed inside our solar system in recent months, The New York Times reports.
The whole thing started late in 2017 when astronomers in Hawaii discovered an object the dubbed Oumuamua. (Hawaiian for "scout.")
Oumuamua is the first known interstellar object ever found. Astronomers know it came from another star because of the speed with which it moved past the sun. But no one really considered it to be anything other than organic in nature — except Loeb and his colleague Shmuel Bialy.
"Considering an artificial origin, one possibility is that 'Oumuamua' is a lightsail, floating in interstellar space as a debris from an advanced technological equipment," the two wrote in Astrophysical Journal Letters this past November.
While alien enthusiasts where naturally enthused, the academic community gave them a less than, say, stellar, reception.
Most of Loeb's peers believe Oumuamua is rock of some sort, perhaps an asteroid or a comet now out of its place. But Loeb says it is moving too fast to be a rock, moving away from the sun as if being pushed.
"Oumuamua's behavior means it can't be, as is commonly imagined, a clump of rock shaped like a long potato, but rather an object that's very long and no more than 1 millimeter thick, perhaps like a kilometer-long obloid pancake — or a ship sail — so light and thin that sunlight is pushing it out of our solar system," Loeb says.
Loeb says he cannot say with certainty the object was built by an alien civilization, but he is sticking with his hypothesis until someone convinces him otherwise. And he says all the media interviews he is doing will not shut him up either.
"Many people expected once there would be this publicity, I would back down," he said. "It changes your perception on reality, just knowing that we're not alone. We are fighting on borders, on resources. . . . It would make us feel part of planet Earth as a civilization rather than individual countries voting on Brexit."