NASA is at a loss to explain mysterious circular formations appearing in Arctic ice.
On Twitter, NASA Earth shared pictures of the “Curious Circles”, which have appeared in the Beaufort Sea.
According to the organisation’s Earth Observatory, the mysterious circles were photographed by IceBridge scientist John Sonntag from a plane.
“I don’t recall seeing this sort of thing elsewhere,” Mr Sonntag said.
Researchers have a number of different theories.
Dartmouth College’s sea ice geophysicist Don Perovich described the ice as “thin, soft, and mushy and somewhat pliable”.
The weird patterns could have occurred as the result of thin ice colliding.
But Chris Shuman, a University of Maryland at Baltimore County glaciologist based at NASA’s Goddard Space Flight Centre, said it was possible they were formed by “warm springs” flowing from inland mountains.
No-one’s been able to determine exactly what the holes are yet, with NASA writing in its Earth Observatory blog “indeed, the holes are difficult to explain”.