Magnetosphere of Jupiter By 1973 the magnetic moment was known within a factor of two, whereas the tilt was correctly estimated at about 10°. The modulation of Jupiter's DAM by Io (the so-called Io-DAM) was discovered in 1964, and allowed Jupiter's rotation period to be precisely determined. The definitive discovery of the Jovian magnetic field occurred in December 1973, when the Pioneer 10 spacecraft flew near the planet. As of 2009 a total of eight spacecraft have flown around Jupiter and all have contributed to the present knowledge of the Jovian magnetosphere. The first space probe to reach Jupiter was Pioneer 10 in
Saturn Atmospheric Entry Probe Saturn Atmospheric Entry Probe The Saturn Atmospheric Entry Probe is a mission concept under study since 2010, where a robotic spacecraft would deliver a single probe into Saturn to study its atmosphere. Due to the orbits and relative positions of Saturn and Earth, launch is proposed for August 30, 2027 for a June 22, 2034 arrival. The mission is under review in order to compete for funding by NASA's New Frontiers Program. To unveil the processes of outer planet formation and Solar System evolution, detailed studies of the composition, structure, and dynamics of giant planet interiors and atmospheres would be