Vortex rings blown from Mount Etna’s vents drift through the dawn light in this beautiful image from Dario Giannobile. Little is required to create vortex rings — they are a puff of fluid shaped by an orifice — but they are relatively unusual to see around volcanoes. Etna is an exception; it happens to have one or more vents that frequently form rings. Their shape and the venting pattern of the volcano must be unusually well-suited to ring formation. (Image credit: D. Giannobile; via APOD)
Vortex Rings at Dawn
