Io,
a Continuing Story of Discovery
Io Quick-Look Statistics
Discovery: Jan 7, 1610 by Galileo Galilei Diameter (km): 3,630 Mass (kg): 8.94x10?22 Mass (Earth = 1) 0.014960 Surface Gravity (Earth = 1): 0.183 Mean Distance from Jupiter (km): 421,600 Mean Distance From Jupiter (Rj): 5.905 Mean Distance from Sun (AU): 5.20 Orbital period (days): 1.769138 Rotational period (days): 1.769138 Density (gm/cm?3) 3.57 Orbit Eccentricity: 0.0041 Orbit Inclination (degrees): 0.040 Orbit Speed (km/sec): 17.34 Escape velocity (km/sec): 2.56 Visual Albedo: 0.61 Typical Subsolar Temperature (K) ~135 Typical Hotspot Temperature (K) ~300 Surface Composition: SulphurA Summary of Facts about Io
Latest Io Science Findings
Frequently Asked Questions about Io
Io Images
Volcanic Changes:
Atmosphere:
Galileo Images
Io Encounter Animations from Galileo Images
Images from Other Missions
Animations from Non-Galileo Data
Look here for information on how to setup your browser for animations.
Educational Activities and Resources
The Mythology of Jupiter and Its Satellites
The planets and moons in our solar system are all named for characters in Greek
and Roman mythology. Here are some stories and artwork about the namesakes
of Jupiter and the Galilean satellites.
The Discovery of the Galilean Satellites
Find out how Galileo Galilei discovered the moons around Jupiter.
Frequently asked Questions (FAQs)
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| Comments and suggestions about this home page may be directed to gllbug@jplpio.jpl.nasa.gov Last updated: 8/24/99 |
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