Moon of Jupiter, one of the Galeleian Moons.

Very interesting moon, see Evidence of Ocean on Europa. Could possibly contain some life forms smiliar to ones that exist in the oceans on Earth. If, if, if and if, of course, but the thought can keep you awake at night.

Discovery:                             Jan 7, 1610 by Galileo Galilei
Diameter (km):                         3,138                 
Mass (kg):                             4.8e22 kg 
Mass (Earth = 1)                       0.0083021 
Surface Gravity (Earth = 1):           0.135
Mean Distance from Jupiter (km):       670,900
Mean Distance From Jupiter (Rj):       9.5 
Mean Distance from Sun (AU):           5.203
Orbital period (days):                 3.551181 
Rotational period  (days):             3.551181 
Density (gm/cm3)                       3.01
Orbit Eccentricity:                    0.009
Orbit Inclination (degrees):           0.470
Orbit Speed (km/sec):                  13.74
Escape velocity (km/sec):              2.02 
Visual Albedo:                         0.63
Subsolar Temperature (K):              ?
Equatorial Subsurface Temperature (K): ?
Surface Composition:                   Water, Ice
Data from NASA