"On arrival to Jupiter, December 7th, 1995, Galileo became the first spacecraft to orbit aroundĀ a gas giant planet,Ā and the first to drop a probe into a giant planet's dense atmosphere. In the aboveĀ Hubble Space Telescope image, the probe entry location is indicated by the arrow. TheĀ atmospheric probeĀ relayed information about temperature, pressure, and composition for about an hour as it descended through Jupiter's clouds, while the orbiter spent at least two years exploring theĀ Jovian system. Along with advancing our knowledge of Jupiter and its environs, Galileo data was expected to reveal some of the secrets of the formation and evolution of theĀ Solar System."