Italy's Mount Etna volcano has released volcanic vortex rings, a rare phenomenon caused by a constant release of vapours and gases.
Volcanologists say the rings are made of condensed water which forms when hot vapour from the volcano hits cold air.
On its own it is colourless but once it reaches the condensation level then it becomes whitish — and that's what we are seeing.
The water vapour is coming out very hot and then once it reaches shallow levels, like atmospheric levels, it then encounters cold air and that's when we get this condensation.
Mount Etna is one of Europe's most active volcanoes. However, the likelihood of pressure building and causing "explosive eruptions" was reduced because it was constantly degassing.