Thursday, 22 November, 2018

Cigar-shaped comet may actually be an alien probe, Harvard scientists suggest

Illustration of Oumuamua Illustration of Oumuamua. Credit European Space Organisation M Kornmesser
Theresa Hayes | 08 November, 2018, 00:04

The object's "excess acceleration" when it travelled through our solar system and its peculiar trajectory distinguishes it from comets and asteroids, the researchers explained.

It was moving at 59,030mph when it was first tracked by scientists.

'Oumuamua is the first interstellar object ever observed in the solar system.

"News reports that a team of scientists studying the odd, "reddish, stadium-sized" mass that 'tumbled past the sun" in late 2017 say they believe the item could be extraterrestrial in nature, and may not be natural.

When the object - known as Oumuamua - flew past the sun, astronomers rushed to find out more about it and reviewed data discovering that the object gained speed instead of slowing down.

In their new paper, Shmuel Bialy and Abraham Loeb of the Harvard Smithsonian Center for Astrophysics suggest Oumuamua could have been "a lightsail of artificial origin".

"This would account for the various anomalies of 'Oumuamua, such as the unusual geometry inferred from its light-curve, its low thermal emission, suggesting high reflectivity, and its deviation from a Keplerian orbit without any sign of a cometary tail or spin-up torques".

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".

"I've been saying for years that the only thing that could happen that would make this more insane and I don't think anybody would blink, is if all of a sudden an alien spacecraft appeared above Earth", he added.

In their paper, the Harvard scientists say the only way to know for sure is to keep watch and see what else shows up in our solar system.

"In science", he said in an email, "we must ask ourselves, "Where is the evidence?, not "Where is the lack of evidence so that I can fit in any hypothesis that I like?"

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.

Bailer-Jones, who earlier this year led a group of scientists who identified four dwarf stars as likely origin points for Oumuamua, raised questions in particular about the object's tumbling motion. However, he adds that, if Oumuamua is indeed a lightsail, it may have run into our solar system "like a ship bumping into a buoy on the surface of the ocean".

"I follow the maxim of Sherlock Holmes: When you have excluded the impossible, whatever remains, however improbable, must be the truth", Loeb said.