Oumuamua, which translates as "distant messenger from the past" in Hawaiian, can reach speeds of up to 196,000mph.
When Oumuamua was spotted past year, scientists observed that its speed had increased after passing the Sun. "Moreover, comets change the period of their spin and no such change was detected for Oumuamua", Loeb said.
Scientists have been confounded by the interstellar object first spotted tumbling past the sun a year ago via telescopes on Maui.
"This unusual object ... is less than [400 metres] in diameter and is moving remarkably fast", NASA said at the time.
"Beyond that, it becomes hard to trace because of the motion of the stars and any hypothetical alien civilisation would face the same issue in charting a course that long in the first place (aside from arguments about whether they would want to launch a craft they knew would not reach its destination for many millions of years)", Jackson said.
The estimated 400 metre-long object sped through our inner solar system at a speed of more than 26 kilometres per second before departing in January 2018.
In November, a pair of Harvard researchers will publish a scientific paper in The Astrophysical Journal Letters, raising the possibility that Oumuamua could be a "fully operational probe sent intentionally to Earth vicinity by an alien civilisation".
"Astronomers are urgently working to point telescopes around the world and in space at this notable object".
But since Oumuamua's discovery, scientists have continued to wonder whether it could have originated from some intelligent life-form.
If the interstellar object is as thin as astronomers estimate it to be, Loeb and Bialy suggest it could be a light sail, which is conceived as able to harness light or solar energy from the sun to propel a spacecraft. NBC News reports that denizens of this planet have launched their own lightsail probes, mostly to investigate other star systems, now unreachable by humans.
The scientists confessed that even if their theory turned out to be true, then there was still the possibility that it was just a "defunct sail floating under the influence of gravity and stellar radiation".
According to Harvard scientists, we may not be alone in our solar system. It's the first interstellar object mankind has ever seen, and it's sparked a ton of debate over its origins and what exactly it was.
"I follow the maxim of Sherlock Holmes: When you have excluded the impossible, whatever remains, however improbable, must be the truth", Loeb said.