The Earth is one of the most volcanically active bodies in our solar system, but it's not alone in having volcanic activity. Jupiter's moon Io is one of the most volcanically active bodies scientists have ever observed and three massive eruptions were discovered on the surface of the moon. These three major events were imaged in August 2013, but the images have only now been released.
The trio of eruptions was recorded in a two-week span, surprising researchers because only 13 major eruptions have been recording between 1978 and 2006. Scientists expect a massive outburst once every one or two years. This event recorded three extremely bright outbursts in a span of two weeks.
The scientists believe that these outbursts show that if they looked at Io more frequently, more outbursts would be noted. Io is only 2300 miles wide, making it about the same size as the Earth's moon. The volcanic activity is the result of Jupiter and neighboring moons pulling on Io causing its insides to heat up.