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
Space probe ringed system and moons. The NASA probe was launched with ESA lander Huygens on October 1, 1997 from Cape Canaveral. The Cassini probe entered Saturn orbit on July 1, 2004, and Huygens landed on Titan, Saturn's largest moon, on January 14, 2005. On September 15, 2017, the probe was de-orbited and burned up in Saturn's atmosphere, after almost 20 years in space. First probe to be launched to Pluto. Launched on January 19, 2006, it flew by the Pluto–Charon system on July 14, 2015. First spacecraft to visit and orbit a protoplanet (4 Vesta), entering orbit on July 16, 2011.