Illustration of the Pioneer 10 space probe as it flies past Jupiter. Pioneer 10 launched on the 2nd March 1972 on a mission, along with its sister probe Pioneer 11, to study the outer Solar System. In December 1973 Pioneer 10 was the first probe to encounter Jupiter. It imaged the planet and its moons, and measured its radiation belts, magnetic field, atmosphere and interior. After encountering Jupiter the probe continued its journey, passing the orbits of Saturn, Pluto and Neptune, and becoming the first probe to exit the Solar System in June 1983. Radio communication with the probe was lost in January 2003 when it was 12 billion kilometres from Earth.