IO: ONE OF THE STRANGEST PLACES IN THE SOLAR SYSTEM
Io’s colors derive from sulfur and molten silicate rock
A bit larger than Earth’s Moon, Io is the third largest of Jupiter’s moons, and the fifth one in distance from the planet.
Io’s mountains are much taller than those on Earth, reaching heights of 16 kilometers (52,000 feet).
The unusual surface of Io is kept very young by its system of active volcanoes. In fact, it’s the most volcanically active body in the solar system
The intense tidal gravity of Jupiter stretches Io and the resulting friction greatly heats Io’s interior, causing molten rock to explode through the surface.
Io’s volcanoes are so active that they are effectively turning the whole moon inside out. Some of Io’s volcanic lava is so hot it glows in the dark.
Volcanic plumes rise 300 km (190 miles) above the surface, with material spewing out at nearly half the required escape velocity.
Io can develop 400,000 volts across itself and create an electric current of 3 million amperes. This current takes the path of least resistance along Jupiter’s magnetic field lines to the planet’s surface, creating lightning in Jupiter’s upper atmosphere.
As Jupiter rotates, it takes its magnetic field around with it, sweeping past Io and stripping off about 1,000 kg (1 ton) of Io’s material every second! This material becomes ionized in the magnetic field and forms a doughnut-shaped cloud of intense radiation referred to as a plasma torus. Some of the ions are pulled into Jupiter’s atmosphere along the magnetic lines of force and create auroras in the planet’s upper atmosphere. It is the ions escaping from this torus that inflate Jupiter’s magnetosphere to over twice as big as expected.