Harvard researchers say it's possible that a mysterious object hurtling through space could be an alien spacecraft sent intentionally to Earth's vicinity by another civilisation. Now, astronomers Shmuel Bialy and Abraham Loeb of the Harvard Smithsonian Center for Astrophysics have released a scientific paper asking if Oumuamua could be a "lightsail of artificial origin", part of a space probe developed by an advanced extraterrestrial civilization.
In late October, 2017, NASA said the recently discovered interstellar visitor appeared "to have originated from outside the solar system, coming from somewhere else in our galaxy". It's dark red, somewhere between 250m and one kilometre long, ten times longer than it is wide, and is spinning end-over-end through space at about 196,000 miles per hour.
"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.
"It is going extremely fast and on such a trajectory that we can say with confidence that this object is on its way out of the solar system and not coming back", Mr Farnocchia said shortly after its discovery.
That shape would allow solar radiation to push the vessel along and explains the object's unusual acceleration. "Lightsails with similar dimensions have been designed and constructed by our own civilization", an excerpt from the paper read.
Although it's been called a comet or an asteroid in the past, it's still unclear exactly what the elongated, red-tinged object is and where it came from.
Oumuamua has left our solar system and is no longer capable of being seen - but as Loeb points out, the existence of Oumuamua suggests there are others like it yet to be found. "Technology light sails may be used to transport cargo between planets or between the stars".
"But, Loeb said, the fact that we've observed one interstellar object like Oumuama suggests that others may be out there". But 'Oumuamua didn't have a "coma", the atmosphere and dust that surrounds comets as they melt.
Of course, the pair aren't claiming that Oumuamua's definitely of alien origin.
The other possibility? It comes from aliens.
Claiming the vessel may be made by aliens, Dr Bialy told The Times: 'Even if there's a small chance it's so interesting that we can't ignore it'.
According to NASA, this interstellar object was a "metallic or rocky object" about 400 metres long and 40 metres wide.