Footage of gigantic smoke rings rising into the sky above Mount Etna in Sicily.
The video, filmed by video photographers Giuseppe Distefano and Marco Restivo on March 16 just half an hour before a major eruption, shows the extremely rare rings, which are actually gas-based.
The phenomenon doesn't happen all the time because the steam and gas rings require certain special conditions to form, such as circular volcanic vents as well as the expulsion of gas at intervals at the appropriate velocity.
