https://www.cnet.com/news/giant-spinning-ice-disc-in-river-looks-like-the-moon-fell-to-earth/

"The mysterious Ice Disk is still spinning today in Westbrook. Come down to the River Walk, take a selfie, and grab some lunch at one of our awesome nearby restaurants," the city later said on Facebook.

Though spinning ice discs are unusual, they're also well-documented. They occur in cold conditions in slow waters. An 1895 issue of Scientific American magazine referenced a "revolving ice cake" on the Mianus River in New York, calling it a "curious formation."