Galileo (spacecraft) - Jupiter Science

Jupiter Science

After arriving on December 7, 1995 and completing 35 orbits around Jupiter throughout a nearly eight year mission, the Galileo Orbiter was destroyed during a controlled impact with Jupiter on September 21, 2003. During that intervening time, Galileo forever changed the way scientists saw Jupiter and provided a wealth of information on the moons orbiting the planet which will be studied for years to come. Culled from NASA's press kit, the top orbiter science results were:

• Galileo made the first observation of ammonia clouds in another planet's atmosphere. The atmosphere creates ammonia ice particles from material coming up from lower depths.
• The moon Io was confirmed to have extensive volcanic activity that is 100 times greater than that found on Earth. The heat and frequency of eruptions are reminiscent of early Earth.
• Complex plasma interactions in Io's atmosphere create immense electrical currents which couple to Jupiter's atmosphere.
• Several lines of evidence from Galileo support the theory that liquid oceans exist under Europa's icy surface.
• Ganymede possesses its own, substantial magnetic field - the first satellite known to have one.
• Galileo magnetic data provide evidence that Europa, Ganymede and Callisto have a liquid-saltwater layer under the visible surface.
• Evidence exists that Europa, Ganymede, and Callisto all have a thin atmospheric layer known as a 'surface-bound exosphere'.
• Jupiter's ring system is formed by dust kicked up as interplanetary meteoroids smash into the planet's four small inner moons. The outermost ring is actually two rings, one embedded with the other. There is probably a separate ring along Amalthea's orbit, as well.
• The Galileo spacecraft identified the global structure and dynamics of a giant planet's magnetosphere.