Asteroid Oumuamua was discovered to have entered our solar system by University of Hawaii astronomers in October 2017. Initially dubbed an anomaly, this mysterious object proved to be the first interstellar object ever detected entering our solar system. Astrophysicists called the strange cigar-shaped asteroid “Oumuamua” – the Hawaiian word for scout or messenger. And this unique extraterrestrial visitor, with its unusual alien spaceship shape and unknown origins, immediately fired imaginations of both the scientific community and conspiracy theorists around the world.
Eminent Harvard University astronomer Avi Loeb led proponents suggesting Oumuamua could be an alien messenger spaceship, arguing it is scientifically imperative to at least entertain the Oumuamua alien probe theory until the evidence shows otherwise.
The astronomer told Express.co.uk at the time: “There is all this baggage from science fiction and Unidentified Flying objects (UFOs).
“And that is why the scientific community shies away from discussing the search for extraterrestrial civilisations.”
But now a review of all the data collected about Oumuamua has concluded everything about it can be explained by natural processes.
The means interstellar asteroid Oumuamua is almost definitely not an alien spaceship.
Oumuamua is a weird object: it is cigar-shaped, six times as long as it is wide, and tumbling end over end every eight hours.
Researchers have suggested that it could be a shard of a planet that got too close to its star and was ripped apart.
Alternatively, interstellar dust may have ground it down into its unusual shape over the course the journey to our solar system.
But the most bizarre aspect about is its acceleration.
Oumuamua started to speed-up as it travelled past the Sun, more than could be accounted for by gravitational forces alone.
The simplest explanation was that, like a comet, it was releasing dust and gas as the Sun heated it up, and acting as a type of thruster pushing it forward.
However, observations showed there was no such small-grained dust emanating from Oumuamua.
This led some scientists to speculate Oumuamua might be solar sail-shaped, and the Sun’s light alone was pushing it to speed up.
A few others even speculated the space rock could actually be a solar sail built and sent here by aliens.
However, Matthew Knight of the University of Maryland can now confirm that is not the case.
He said: “The argument for the solar sail is that it has to be aligned with our sun to give it the acceleration that we see.
“You cannot have it be working as a solar sail and also spinning.”
Oumuamua could instead be outgassing water vapour, just at a level lower than scientists are able to detect.
Dr Knight said: “There are plenty of ways to form it that do not involve aliens, and I do not think there is any reason to invoke something that extraordinary unless we rule everything else out.”
Oumuamua has now travelled too far away to make any more observations, meaning the data we have is all scientists will have until another interstellar object is spotted.
Dr Knight added: “The next time an interstellar object is discovered we will be better prepared with the things we want to know about it.”