Io is one of the four Galilean moons of planet Jupiter. It is the hottest moon in the solar system, recording up to 2,600°F around its 400 volcanoes, hotter than Earth's volcanoes. Due to its proximity to Jupiter, it receives 3,600 rem of radiation a day (compared to 0.001 rem per day on Earth). This is thousands of times stronger than needed to kill a human being.
Io, along with Ganymede, Europa, and Callisto, were discovered by the Italian astronomer Galileo Galilei in 1610.
Pan, zoom, or go full-screen with this megapixel image of Callisto.
Io has hundreds of volcanoes, patera (large caldera or volcanic craters), and lava flows on it's surface. There is believed to be a sulfur magma ocean beneath it's surface that feeds the volcanoes, with temperatures of 2,420°F during eruption.
Io's volcanoes eject plumes of sulfur into space that become ionized as Io moves through Jupiter's magnetosphere, forming the Io plasma torus. This gigantic torus is filled with sulfur and oxygen ions that have a temperature of about 1 million °C / 1.8 million °F.
As Io orbits around Jupiter inside the plasma torus, electrical currents are generated from the surface of Io to the north and south poles of Jupiter, forming aurorae.
This current flow "channel" is called the Io flux tube, and generates 5 million amps at 400 volts, producing 2 trillion watts of power.
Here are the major volcanic features of Io.
And now I see with eye serene, The very pulse of the machine. A being breathing thoughtful breaths, A traveler between life and death.
- William Wordsworth / Love, Death & Robots (Netflix)