Io: Radioactive volcano moon of Jupiter
Io is one of the 4 Galilean moons of the 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 1,000 times stronger than needed to kill a human being.
Io, along with Callisto, Europa, and Ganymede, (the Galilean moons) were discovered by the Italian astronomer Galileo Galilei in 1610.
For a listing of all moons, see Moons of the Planets.
Io Facts
- Mass (kg)
- 8.94 x 1022
- Radius (km)
- 1,815
- Density (gm/cm3)
- 3.55
- Distance from planet (km)
- 421,600
- Rotational period (days)
- 1.769138
- Orbital period (days)
- 1.769138
- Orbital velocity (km/sec)
- 17.34
- Eccentricity of orbit
- 0.004
- Inclination of orbit (°)
- 0.040
- Albedo
- 0.61
- Magnitude (Vo)
- 5.02
- Atmosphere
- 90% sulfur dioxide
Io Surface Map
