"It looks like the moon has landed in Westbrook!" the city posted on its Facebook page.
Doug Bertlesman, whose office overlooks the river - said: "It kind of looks like a crop circle".
A curious formation that's getting attention in Greater Portland is actually a spinning ice disk that is roughly 100 yards (91 meters) wide.
Mark Battle, an associate professor of physics at Bowdoin College in Brunswick, said he's never seen anything like the Westbrook ice disk. "I think it will continue to gain in thickness as long as it keeps spinning", said Mitchell, adding that the massive saucer acted as a giant Lazy Susan for ducks that chose to investigate it.
The city's marketing and communications manager, Tina Radel, told Gizmodo that the ice disk "does not appear to be going up or downstream at this time", adding that "it could get bigger as more ice forms".
A huge spinning ice disk has formed in the Presumpscot River in the city of Westbrook, and people looking for explanations are claiming everything from aliens and crop circles to a giant duck Lazy Susan. "It was a big duck-go-round".
When another city resident shared a drone video of the ice rotating, Rachael Delcourt referenced another legend from the city - the large tropical snake nicknamed "Wessie" who made the river home in 2016.
"I have not personally [seen an ice disk like this], but these are seen occasionally in the right conditions, usually at a bend in a river where eddies are common", Walt Meier, senior research scientist at the National Snow and Ice Data Center, told Live Science.
Westbrook is a city of 17,500 just to the west of Portland.
