Io
MEAN RADIUS: 1830 km
MASS: 0.0149 (Earth=1)
DENSITY: 3.55 (gm/cm)
GRAVITY: 0.138 (Earth=1)
ORBIT PERIOD: 1.769 (Earth days)
ROTATION PERIOD: 1.769 (Earth days)
SEMIMAJOR AXIS OF ORBIT: 422,600 km
ECCENTRICITY OF ORBIT: 0.004