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
Japanese Lunar Exploration Program planned mission to Mars, consisting of an orbiter (MELOS-1), and a lander (MELOS-2). It would be the successor to the comet probe Suisei (PLANET-A) the Mars probe Nozomi (PLANET-B), and the Venus probe Akatsuki (PLANET-C). MELOS-1 is planned to be launched in 2018, and will also have up to four small landers. Hiten, or MUSES-A (Mu Space Engineering Satellite-A) is a technology demonstration satellite built by ISAS, launched on January 24, 1990. LUNAR-A was an ISAS mission consisting of a lunar space craft which would have carried two penetrators to the Moon, and deploy them at an altitude of 40