Probes from NASA and ESA may head to Europa in a little while. According to the New Scientist, the two space agencies have picked the icy Jupiter moon for a joint mission that would see two probes launch in 2020. The probes would arrive at their destination in 2026 and "spend at least three years studying the system." New Scientist has more:
The prime target of NASA's orbiter is Jupiter's moon Europa, which is thought to have an ocean of liquid water beneath its icy shell. . . . Mapping the surface could reveal promising landing sites for future missions. Like Earth's ocean, Europa's inner ocean is thought to rest directly on rock, which could provide nutrients that make it a promising place to look for life.
ESA's probe would settle into orbit around Ganymede, the largest moon in the solar system and the only one known to make its own magnetic field. . . . The pair of probes would also be used to conduct joint studies of Jupiter's intense magnetic field.
Reportedly, the NASA orbiter could help determine the thickness of Europa's ice shell. If the shell is thin enough to let sunlight and radiation in through cracks, that could make the presence of life in the inner ocean likelier.
NASA and ESA still need to secure funding for the endeavor, though. New Scientist says ESA faces an "added hurdle," because the Ganymede probe is competing with an X-ray telescope and gravitational wave detector for approval. The European agency will pick a winner in 2011.