Exploration of Jupiter reach Europa after a 6.5 year cruise. The spacecraft would fly by the moon 32 times to minimize radiation damage. Because of the possibility of subsurface liquid oceans on Jupiter's moons Europa, Ganymede and Callisto, there has been great interest in studying the icy moons in detail. Funding difficulties have delayed progress. The "Europa Orbiter" was a planned NASA mission to Europa, which was canceled in 2002. Its main objectives included determining the presence or absence of a subsurface ocean and identifying candidate sites for future lander missions. NASA's "JIMO" ("Jupiter Icy Moons Orbiter"), which was canceled in 2005, and
Thyone (moon) known as Semele, mother of Dionysus in Greek mythology. Thyone belongs to the Ananke group, retrograde irregular moons which orbit Jupiter between 19.3 and 22.7 million kilometres, at inclinations of roughly 150°. Thyone (moon) Thyone ( ; Greek: "Θυώνη"), also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard, et al. in 2001, and given the temporary designation '. Thyone is about 4 kilometres in diameter, and orbits Jupiter at an average distance of 21.406 million kilometres in 639.803 days, at