Westbrook residents in Maine discovered an interesting phenomenon that left them wondering if they were being visited by extraterrestrial visitors.

Slowly spinning counter clock-wise in the Presumpscot River was a massive disk of ice that scientists assured was simply a natural occurrence, albeit, a very rare one.

The disc that closely resembles the moon is supposedly formed with the help of a cross current creating a whirlpool in frigid temperatures.

But is it as simple as that?

However, the exact cause of the icy disc eludes University of Southern Maine physics professor, Paul Nakroshis.

The professor told Maine Public Radio that "It's probably formed — and this is speculation — by the aggregation of small little bits of ice or in an initial big chunk of ice that, because of initial rotation, little pieces of ice glob onto it."

He referred to research found in a monthly scientific journal, called Physical Review E, "in which the researchers created a small ice disk in the laboratory and found that it rotated. But in the preface to their paper they say that the creation of these disks is actually not well understood."

He described the conditions contributing to the unusual sight that is captivating Westbrook residents.

"The paper that I referenced talks about the cause of the rotation being the ice melting underneath the disk, and as it melts the water sinks downward and causes a vortex that causes the disk to rotate."

But Nakroshis found that the spinning glacial matter in Maine did not necessarily correspond with the conditions mentioned from the research paper.

"However, based on my reading of the paper, the water in the Westbrook river is not actually warm enough to cause the effect that the paper talks about."

"So most likely the cause of the rotation is just the river water going by the disk and once it starts rotating in that direction it's probably going to continue."

It's time for a re-christening.

Meanwhile, people braced themselves for the Flat Earthers to start their theorizing.

People preferred speculating over listening to scientific lectures.

Whatever it is, this is the bottom line.

Westbrook is seven miles away from Portland and is experiencing a surge of interest with all the media coverage for their arctic wonder, according to NPR.

The city hopes to lure more visitors before warmer temperatures melt it all away.