In 2003, the U.S. NASA Galileo space probe ended its eight-year mission to Jupiter as planned. The Jet Propulsion Laboratory in Pasadena, California directed the craft into Jupiter's atmosphere to burn up, totally vaporizing its structure. This prevented the possibility of any later uncontrolled fall onto a moon causing contamination with bacterial life from Earth, perhaps carried on the probe since launch. Contact was lost with the spacecraft slightly after 3:40 p.m. EDT. More than 1,000 people who worked on the Galileo program gathered at the Laboratory to celebrate the end of the mission. Galileo was first conceived in 1976 as a mission to Jupiter and its moons, Ganymede, Callisto, Io, and Europa.[Artist's impression of Galileo passing the moon Io, with Jupiter in the background]