Avi Loeb, dean of astronomy at Harvard University, is no stranger to the controversy.
His suggestion is that strange objects entering the solar system from the depths of space may be alien probes, which is just a recent example.
Now, he poured oil on the fire again.
In an interview with the Israeli newspaper Haaretz, the Israeli professor gave a fierce defense of his hypothesis.
"Once we leave the solar system, I am sure we will see a lot of traffic," he said . ".
"We may receive a message, 'Welcome to starclub '.
Or we will find many dead civilizations.
We will find their bodies.
At the heart of the debate is 'Oumuamua '.
Translated from Hawaiian, meaning "Messenger from the distant past ".
"It comes from outside the Zodiac --
Flat swirls of planets, asteroids and other things that rotate in place as the solar system forms.
This is a strange reddish color, suggesting extreme exposure to intense cosmic rays.
At least it's relatively bright compared to normal coal
The black color of most known comets and asteroids.
It moves very, very fast.
When it leaves the sun like a comet, it is considered "accelerated.
But it has no tail of a comet.
People also see it "flashing" quickly as if it was an elongated-or flat —
Objects tumbling in the wild.
"Oumuamu" is of course very strange.
So, what about aliens?
Professor Loeb, 56, teamed up with Shmuel Bialy to publish a paper speculating that "oumuamua" is not a comet.
Not an asteroid.
On the contrary, he believes that if it is an artificial light sailing vessel, its unusual trajectory can be explained.
The search for alien intelligence has been checked: it has put in some valuable radio telescope time to listen carefully to the object. Not a peep.
No radio information or beacons.
No radar position.
But Professor Loeb is not discouraged.
"I don't care what people say," he told Haarets . ".
"What I want to say is to say, if the public is interested in what I say, it is a popular result for me, but it is an indirect result.
Science, unlike politics, is not based on opinion polls.
But he seems keen to increase speculation.
"We cannot know whether this is an active technology or a spaceship that is no longer valid and continues to float in space," the land Daily quoted him as saying . ".
"But if Oumuamua was created with a large number of similar objects randomly emitted, in fact, we found it, this means that its creator sends a quadrilateral probe like it to every star in the galaxy.
Professor Loeb says he thinks there are alien debris everywhere in the universe.
It includes a living society.
He believes that finding them should be our top priority.
"Our approach should be archaeological," he said . "
"Just as we dig underground to discover cultures that no longer exist, we have to dig in space in order to discover civilizations that exist outside the Earth.
Professor Loeb said the scientific community's discussion of the origin of Oumuamua was very extensive.
"Scientists with high status say the goal is special, but they are worried about making their ideas public.
I don't understand.
After all, the purpose of academic tenure is to allow scientists to take risks freely without worrying about their work.
However, he said that scientists are very careful to observe their words when seeking such a high position, which may continue.
"When we ask ourselves questions about the world, we allow ourselves to make mistakes.
We know the world with innocence and honesty.
As a scientist, you should enjoy the privilege of continuing your childhood.
Don't worry about yourself, but expose the truth.
Especially after you get a term.
But critics point to differences between speculation and verifiable assumptions based on measurable quantities.
Michael Brown, an astrophysicist at Monash University, said: "In my opinion, 'crazy speculation' still exists . ".
"The data does not exclude human sources, but the natural interpretation given is consistent with the data, and the natural interpretation must be the first choice.
"It's not speculation to look for alien life," he said . "
"This is much less than assuming dark matter --
An invisible substance that constitutes 85% of the material in the universe.
But this is completely another dispute.
Professor Loeb is also an advocate for Russia's billionaire Yuri Milner's groundbreaking StarCraft program, which aims to build thousands of tiny "star chips" to push our nearest neighbor, Alpha.
That may be why the concept holds such a high position in his mind.
However, he did not know the risks at all.
"So, if it turns out that this is incorrect, I might commit suicide," he said . ".
"On the other hand, if it turns out to be true, it is one of the greatest discoveries in human history.
"Also, what is the worst thing that can happen to me?
My administrative duties were lifted?
This will give me more time to do scientific research.
The story first appeared in the news. com. au.