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
Outer Planet Flagship Mission were two primary candidate missions under study: Europa Jupiter System Mission (EJSM) and Titan Saturn System Mission (TSSM). On February 18, 2009 NASA announced that both missions can proceed forward, but the EJSM is to be the first, departing Earth in 2020 and arriving at Jupiter in 2026. The Titan mission is to be launched later. The Europa mission concept has since changed, with the "Europa Clipper" mission to be launched by NASA, with a target launch date of 2022, and a separate European mission Jupiter Icy Moon Explorer (JUICE). The proposed Titan mission is not currently being developed nor