Location: Orbit of planet Jupiter
Mean orbital distance: 421,700 km
Orbital period: 1.769 days (42.46 hours)
Mean Radius: 1,821.6 km
Innermost of the four Galilean moons of the planet Jupiter. This moon is the most geologically active object in the Solar System with over 400 active volcanoes on its surface. This intense geologic activity is the result of powerful tidal stretching of the moon’s interior caused by Jupiter’s strong gravitational influence. Volcanic eruptions spew debris hundreds of kilometers into space where it eventually orbits Jupiter and dumps vast amounts of energy into its magnetosphere. Several of these plumes of debris move across the surface of Io and exhibit filamentary structures. The origins of these behaviors are currently a mystery to astronomers.
The plumes are the result of intense electrical discharges occurring as a result of Io’s interaction with Jupiter’s immense magnetic field. The electric circuit between the two bodies concentrates material on the moon into dense plasma foci (DPF) or “plasma guns”. The fountain-like shape and extreme temperatures of the plumes closely matches the “penumbra” produced by DPF discharges.