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
History of Mars observation telescope to make astronomical observations. His records indicate that he began observing Mars through a telescope in September 1610. This instrument was too primitive to display any surface detail on the planet, so he set the goal of seeing if Mars exhibited phases of partial darkness similar to Venus or the Moon. Although uncertain of his success, by December he did note that Mars had shrunk in angular size. Polish astronomer Johannes Hevelius succeeded in observing a phase of Mars in 1645. In 1644, the Italian Jesuit Daniello Bartoli reported seeing two darker patches on Mars. During the oppositions of