No one knows what created these strange shapes in the Arctic

Bizarre circular shapes spotted by a research plane in the Arctic's Beaufort Sea are puzzling NASA scientists.

The aerial survey - part of ongoing research trips that started about 10 years ago - was conducted by scientist John Sonntag, the lead researcher on NASA's Operation IceBridge project, charting sea ice levels on both poles of the Earth.

"We saw these sorta-circular features only for a few minutes today," Sonntag wrote as he discovered the circles in real time. "I don't recall seeing this sort of thing elsewhere."

Sonntag and others are at a loss for what the holes might be, but they have a few ideas.

One guess is that the ice is "young" and newly formed over water.

"The ice is likely thin, soft, and mushy and somewhat pliable," sea ice geophysicist Don Perovich told NASA's publication, Earth Observatory. "This can be seen in the wave-like features in front of the middle 'amoeba'."

Another scientist agrees, pointing to the "finger rafting" in the image - the zig-zag pattern along where collided ice met.

"It's definitely an area of thin ice, as you can see finger rafting near the holes and the colour is grey enough to indicate little snow cover," IceBridge researcher Nathan Kurtz said about the landscape near the holes.

"I'm not sure what kind of dynamics could lead to the semi-circle shaped features surrounding the holes," he yielded. "I have never seen anything like that before."

Seals could be the culprit behind the mystery for another scientist who hypothesizes the holes were created as breathing locations by the animals.

"The encircling features may be due to waves of water washing out over the snow and ice when the seals surface," oceanographer and climate scientist Walt Meier told Earth Observatory.

But a NASA glaciologist believes the formations are caused by an undetected weather phenomenon like a submerged flow of hot water.

"This is in pretty shallow water generally, so there is every chance this is just 'warm springs' or seeps of ground water flowing from the mountains inland that make their presence known in this particular area," said researcher Chris Shuman.

But for as many speculative answers there are from trained scientists, there are, likely, just as many far-fetched, X-Files-inspired guesses, as well. For now, the mystery will remain unsolved - at least until further research is conducted.