A giant ice disc was spotted Tuesday morning in the Piscataquis River in Milo. The spinning mass of ice stunned residents before it drifted downstream toward the Route 6 bridge and disintegrated. Credit: Courtesy of Blaine Chadwick | 3Rivers Unmanned Aerial Services

Louise and Stephen Rhoda have watched a number of riveting things happen outside their back door, which faces the Piscataquis River in Milo: deer trying to cross the ice, flooding and, over the last three years, baby eagles.

But on Tuesday morning they woke to something they had never seen before: a spinning disc of ice that nearly spanned the entire width of the river.

“We’ve never seen anything like this,” said Louise Rhoda on Tuesday morning. The couple has lived in the home since 1983, and Stephen Rhoda grew up on the opposite side of the river. “I’ve seen pictures of other places but never dreamed we’d look out here and see it.”

Others watched a time lapse video of the disc captured by a webcam. It appeared to form where the Sebec River runs into the Piscataquis River.

Credit: Courtesy of Blaine Chadwick | 3Rivers Unmanned Aerial Services

This isn’t the first spinning mass of ice to catch the public’s attention. The southern Maine city of Westbrook found itself in the international spotlight 11 months ago, when a massive spinning ice disc formed on the Presumpscot River.

Onlookers from near and far crowded the river’s banks for a glimpse of the 100-yard circular ice formation. Westbrook even capitalized on its momentary internet fame to urge the sudden flood of gawkers to visit local restaurants and businesses.

But such ice discs aren’t exclusive to either Milo or Westbrook. After the appearance of the moon-like disc in Westbrook, others were spotted near Millinocket in Penobscot County, Surry in Hancock County and Haynesville in Aroostook County. In 2014, a mysterious ice circle was spotted in a small stream in Benedicta up in The County.

Ice discs have been known to appear in the Arctic, Scandinavia and Canada, according to the Daily Mail, but the phenomenon remains a puzzle to scientists. A pair of Swedish researchers in a 1997 study in the Royal Meteorological Society journal attributed the formation of ice discs to the “eccentric rotation” of the whirlpool effect.

Another study in the journal Physical Review E suggests that the ice’s rotating motion could be caused by warmer temperatures near the surface of the water. As the warm water rises, it causes the ice to melt and then sink, creating a “vertical vortex” under the disc that gives the ice its spin.

Credit: Courtesy of Blaine Chadwick | 3Rivers Unmanned Aerial Services

Around 9:30 a.m., the disc in Milo traveled with the current under the nearby Route 6 bridge — locally referred to as “the Rhoda bridge” — and shattered.

“If you’ve ever been on a lake when the ice breaks up, that’s the same idea. You could hear the crunching and the grinding as it hit the riverbank,” said Blaine Chadwick of Milo, who watched the ice disc’s demise. He owns 3Rivers Unmanned Aerial Services and captured footage of it with a drone.

“It didn’t hesitate a bit. I thought for sure it was going to stop,” Chadwick said. “The pressure of the river was too great.”

BDN writer Christopher Burns contributed to this report. Mike Russell of ProTech Solutions contributed the webcam footage of the ice disc. Stephen and Louise Rhoda are the reporter’s uncle and aunt.

Related: Westbrook’s mystery ice disc

Erin Rhoda

Erin Rhoda

Erin Rhoda is editor of Maine Focus, a journalism and community engagement initiative by the Bangor Daily News.