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
The Tenth Planet last episode remains missing, although several short clips, including the regeneration sequence, have been discovered intact. In 2013, "The Tenth Planet" was released on DVD with a full-length animated reconstruction of its missing footage. The Doctor and his companions Ben and Polly arrive in the TARDIS at the South Pole in the year 1986. Nearby they find the Snowcap Base, a space tracking station commanded by General Cutler. The base is supervising the mission of the "Zeus IV" spaceship, running a routine probe on the Earth's atmosphere. The spaceship is drawn off-course by an unknown force, and Snowcap monitoring staff