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 launch and adds perspective on how the mission will help scientists understand Earth, including its atmosphere, geology, ecologyand future". Nita Thurman wrote for "The Dallas Morning News", ""Mission: Earth, A Journey to the Home Planet" has dozens of color photos taken inside the shuttle and through its windows. The astronaut's descriptions are vivid." "Publishers Weekly" wrote favorably of the book, saying, "Astronaut Jones's enthusiasm for his work is contagious; it shines through the text, making for a roundly enjoyable and informative read". "Publishers Weekly" recommended the book and said it is, "[w]ell-conceived and thoughtfully executed, this book deserves a wide