Volcanic plumes on Io
Volcanic plumes on Io As New Horizons approached the Jupiter system for its flyby, it captured many images of Io to search for active volcanic plumes. This animation is based upon two images captured on February 26, 2007, from a distance of about 4 million kilometers. NASA / JHUAPL / SwRI / Animation by E. Lakdawalla

A short-exposure image captures the surface features of the volcanically pock-marked moon, while a longer-exposure image reveals two plume fountains silhouetted against black space.  Enhancing the contrast of the longer-exposure image brings out more detail in the plumes, which are from volcanoes named Tvashtar and Prometheus.  Two bright conical shapes visible on the terminator (day/night boundary) are unnamed mountains.