If you have a few weather or science-obsessed Facebook friends, you’ve probably seen videos of so-called “ice circles” circulating online in the last 10 years or so. What are ice circles? They’re those slowly rotating, almost perfectly circular, sometimes giant disks of ice that look like frozen lily pads. Scientists have been studying their mysterious rotations since at least the late 19th century—check out this 1895 mention in Scientific American—but it took until 2016 for a team of Belgian physicists to figure them out.
Even after their breakthrough discovery in March 2016, there’s still some misinformation out there about ice circles, published in supposedly reputable places. This list of ice circle facts will hopefully put that to rest. How do ice circles form, for real? Read on to find out.