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
Mission: Earth, Voyage to the Home Planet Mission: Earth, Voyage to the Home Planet Mission: Earth, Voyage to the Home Planet is a children's literature book by science writer June A. English and astronaut Thomas David Jones that was published in 1996 by Scholastic. Jones was among the crew members of the Space Shuttle "Endeavour" during an eleven-day mission in space, which was launched in April 1994 to study the ecological well-being of Earth using specialized radar technology. The book, which is illustrated with radar images and picturesque photographs, chronicles the mission and Jones' experiences of it. "Mission: Earth, Voyage to the Home Planet" received a generally