A Harvard professor who believes space rock ‘Oumuamua is “the first sign of intelligent life” beyond Earth has a new theory about the space mystery – specifically about why he’s convinced it was built by someone.
‘Oumuamua, estimated to be 200m in diameter, is the first interstellar object ever found in the Milky Way and was first spotted in 2017 by the University of Hawaii’s Pan-STARRS1 telescope while it was looking for comets and asteroids.
The long, cigar-shaped rock was observed by experts to be spinning and accelerating at a phenomenal speed, known as “non-gravitational acceleration,” with some scientists baffled as to why.
The majority of experts agree ‘Oumuamua is probably a new kind of comet propelled by a mechanism we simply don’t understand yet.
But astrobiologist Avi Loeb, the Frank J Baird Professor of Science at Harvard University, has quite a different take.
He believes the rock is the first sign of intelligent life outside our own planet, and is a sign that a spacefaring civilisation is exploring, or did once explore, the universe.
“Although it came from outside the solar system, the initial assumption was that it would turn out to be like a comet from our solar system,” he told the South China Morning Post.
“But a comet leaves a trail of gas behind it and there was nothing like that behind ‘Oumuamua. So clearly it was not a comet.”
He added: “Then people said it was probably an asteroid, just a rock. The problem with that was ‘Oumuamua exhibited an extra push away from the sun.
“In the case of comets, that push is provided by a rocket effect caused by evaporating gases. But there were no such evaporating gases emitting from ‘Oumuamua. So the question is, What gave ‘Oumuamua this extra push?”
Prof Loeb has deduced the rock is a “sail” being propelled through space by photons, and sails (used by scientists on Earth) have to be constructed as they are not naturally occurring.
“‘Oumuamua exhibited a push without any tail behind the object, and no gas, and the only thing that I could think of which could push it is the reflection of sunlight,” he said.
“A solar sail reflects light and is pushed by it, just the way that a sail of a boat reflects the wind.
“That was the only thing that I could think of that would give it that push. I put it on the table that it was likely to have been made by an intelligent civilisation.”
Prof Loeb elaborates on his theory in his new book Extraterrestrial: The First Sign of Intelligent Life Beyond Earth, and acknowledges his beliefs make him an outsider in his field.
“People found it unacceptable to discuss this possibility, and that was a surprise to me.”
He’s previously speculated that our solar system could be filled with a quadrillion alien spaceships of which we have no knowledge.