IO Moon

Textures are based on GalileoSSI and Voyager mosaic - USGS source. Io is the innermost and third-largest of the four Galilean moons of the planet Jupiter. Slightly larger than the Moon, Io is the fourth-largest moon in the Solar System, has the highest density of all of them, and has the lowest amount of water (by atomic ratio) of any known astronomical object in the Solar System. With over 400 active volcanoes, Io is the most geologically active object in the Solar System. This extreme geologic activity is the result of tidal heating from friction generated within Io’s interior as it is pulled between Jupiter and the other Galilean moons. Several volcanoes produce plumes of sulfur and sulfur dioxide that climb as high as 500 km above the surface. Io’s surface is also dotted with more than 100 mountains that have been uplifted by extensive compression at the base of Io’s silicate crust. Some of these peaks are taller than Mount Everest.