We seem to be having a little ’90s resurgence, based mainly on the number of girls I’ve seen wearing high-waisted shorts over tights, and also the fact that they put Beavis and Butt-Head back on TV. So I guess the hip aliens are going back to making mysterious circles, like they used to do in the days before Fortean Times had a website. But this time, instead of decorating the fields of England, they’re punching weird spinning disks out of river ice.

It’s an international phenomenon. The one above is in Canada. This one’s in Scotland:

Reader support helps sustain our work. Donate today to keep our climate news free. All donations matched.

This one’s in Vermont:

Grist thanks its sponsors. Become one.

Best guess on what’s actually happening here: An eddy in the river sets up the spinning motion, and it’s the spinning itself that causes the ice disks to be so perfectly circular. Second best guess: Definitely aliens.