The Partially Watery World of Europa, One of Jupiter's Moons Earth in Space, Vol. 10, No. 4, December 1997, pp.5-8 . Permission is hereby granted to journalists to use this material so long as credit is given, and to teachers to use this material in classrooms.
Recent explorations discover evidence of subsurface water on one of Jupiter's ice-ridden satellites.
On a cold, clear night in 1610 in northern Italy, Galileo Galilei made the remarkable discovery of moons swirling around Jupiter. Of particular interest is the second large satellite outward from Jupiter, the moon now known as Europa. It is likely that Galileo would be as delighted and as mystified as today's planetary scientists in seeing this bizarre, icy world. Europa's Composition and Characteristics Europa is one of the brightest objects in the Solar System, and the way it reflects sunlight shows that water ice is a dominant part of the surface. Europa is almost the same diameter as Earth's Moon, but has a slightly lower overall density.