This chart shows the differences between Io and Jupiter. To change the planets/moons being compared, change one or more of the form fields at the bottom and click Refresh.

	Io	Jupiter
Discovered By	Galileo Galilei	Known by the Ancients
Date of Discovery	1610	Unknown
Average Orbit Distance	421,800 km	778,340,821 km
Perihelion/Perigee (closest)	420,071 km	740,679,835 km
Aphelion/Apogee (farthest)	423,529 km	816,001,807 km
Equatorial Radius	1821.6 km	69,911 km
Equatorial Circumference	11,445.5 km	439,263.8 km
Volume	25,319,064,907 km3	1,431,281,810,739,360 km3
Mass	89,319,379,731,108,900,000,000 kg	1,898,130,000,000,000,000,000,000,000 kg
Density	3.528 g/cm3	1.326 g/cm3
Surface Area	41,698,064.74 km2	61,418,738,571 km2
Equatorial Surface Gravity	1.796 m/s2	24.79 m/s2
Escape Velocity	8,552 km/h	216,720 km/h
Rotation Period (Length of Day)	1.769 sidereal days	0.41354 sidereal days
Mean Orbit Velocity	62,423.1 km/h	47,002 km/h
Orbit Eccentricity	0.0041	0.04838624
Orbit Inclination to Ecliptic	0.036 degree	1.304 degrees
Orbit Circumference	2,650,236.42 km	4,887,595,931 km
Atmospheric Constituents	Sulfur dioxide	Hydrogen, Helium