Last month, Italy's Mount Etna puffed out perfectly round volcanic smoke rings. While they're not unusual to see from a volcano (they're not exactly common either), scientists were curious about the frequency in which they were produced.
According to reports, a volcano produces smoke rings, which aren't actually smoke, when gas and water vapor mix and form inside a newly formed crater. They get pushed through a narrow hole and out comes a donut ring.
What makes Mount Etna so unusual is that it spewed volcanic smoke rings for an entire week and you don't usually see more than a few. However, Mount Etna, which is located near Sicily, is also one of the most active volcanoes in Italy as it erupts multiple times a year.
While scientists can trace Mount Etna's volcanic activity back half a million years, people have been documenting eruptions for roughly 2,700 years. It's also protected as a World Heritage Site.
In videos and images posted to social media, you can see multiple volcanic smoke rings in the sky at once. Experts told reporters that the frequency of the rings has "broken all previous records."
