Europa's vital statistics

Discovered first by Galileo Galilei, the Italian astronomer, in 1610, Europa is the fourth largest of Jupiter's 16 moons, after Ganymede, Calisto and lo. Its diameter is nearly 3,050 km, almost the size of the Earth's moon. The surface is icy and result of internal planetary dynamics as ocean currents. Europa will be the cynosure of attention once again on December 19 this year, when Galileo will fly within 965 km of it and again of February 20,1997, when the probe will take pictures of it from as near as 600 km, and later on November 6,1997.