Galileo's Final Blaze of Glory
EccentricAnomaly writes: "CNN reports that the Galileo spacecraft is about to perform its last flyby of Io. Galileo will skim a mere 100 km above Io to enter a trajectory that crashes into Jupiter in 2003. This is to avoid the spacecraft running out of fuel and accidentally crashing into Europa which might contaminate it with any bacteria spores on Galileo. This is a real concern - Apollo 12 found bacteria on Surveyor 3 that survived two and a half years on the moon."
Jupiter has no solid surface, It is a gas giant. Technicaly it is a Brown Dwarf- which is a star that never got large enough to start a fusion chain reaction. It is extremely unlikely that any sentient life could form there, especialy considering the gravity is strong enough to compress the hydrogen atmosphere into a liquid metal at it's core, which produces the strongest magnetic field in the solar system.
Europa, on the other hand, has everything life needs to flourish. Water- most likely in a huge ocean under the surface ice, and energy- mainly geothermic energy produced by the mammoth gravitational force exerted by jupiter (the same ones that make io the most volcanicly active body in the solar system), as well as a phenominal amount of magnetic flux produced by hydrogens metalic core.
Now if you ask me, I'd prefer to burn a probe up in a dead star then a moon which could possibly support life.