Europa [yur-ROH-pah] is a unique moon of Jupiter that has fascinated scientists for hundreds of years. Its surface is among the brightest in the solar system, a consequence of sunlight reflecting off a relatively young icy crust. Its face is also among the smoothest, lacking the heavily cratered appearance characteristic of Callisto and Ganymede. Lines and cracks wrap the exterior as if a child had scribbled around it. Europa may be internally active, and its crust may have, or had in the past, liquid water which can harbor life.
Europa is named after the beautiful Phoenician princess who, according to Greek mythology, Zeus saw gathering flowers and immediately fell in love with. Zeus transformed himself into a white bull and carried Europa away to the island of Crete. He then revealed his true identity and Europa became the first queen of Crete. By Zeus, she mothered Trojan war contemporaries Minos, Rhadamanthus, and Sarpedon. Zeus later re-created the shape of the white bull in the stars which is now known as the constellation Taurus.
The fascination with Europa began centuries ago in 1610 when Galileo Galilei discovered four Jovian satellites: Io, Callisto, Ganymede, and Europa. But only recently have we begun to learn more about the sphere. About forty years ago, modern astronomer Gerard Kuiper and others showed that Europa’s crust was composed of water and ice. In the 1970s, space exploration of Jupiter’s satellite system began with the Pioneer and Voyager fly-by missions which verified Kuiper’s analysis of Europa and discovered other characteristics. In 1995, the Galileo spacecraft began gathering more detailed images and measurements within the system, providing the information needed to piece together Europa’s past, present, and future.