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
Journey to Jupiter the giant planet. A diversion to the jagged Io offers their only chance of survival. Journey to Jupiter Journey to Jupiter is a juvenile science fiction novel, the eighth in Hugh Walters' "Chris Godfrey of U.N.E.X.A." series. It was published in the UK by Faber in 1965 and in the US by Criterion Books in 1966. The first manned expedition to Jupiter reaches speeds never experienced before; despite this it takes several months to reach its objective, leading to tensions among the crew, as well as serious vision problems caused by "light slip". A miscalculation in the gravity of Jupiter