In 1988, in an article on the analysis of the measurements of the variations in the radial velocities of a number of stars, Campbell, Walker, and Yang reported an - teresting phenomenon;the radial velocity variations of Cephei seemed to suggest the existence of a Jupiter-like planet around this star. This was a very exciting and, at the same time, very surprising discovery. It was exciting because if true, it would have marked the detection of the ?rst planet outside of our solar system. It was surprising because the planet-hosting star is the primary of a binary system with a separation less than 19 AU, a distance comparable to the planetary distances in our solar system. The moderatelyclose orbit of the stellar companionof Cephei raised questions about the reality of its planet. The skepticism over the interpretation of the results (which was primarily based on the idea that binary star systems with small sepa- tions would not be favorable places for planet formation) became so strong that in a subsequent paper in 1992, Walker and his colleagues suggested that the planet in the Cephei binary might not be real, and the variations in the radial velocity of this star might have been due to its chromospheric activities.

This contributed monograph is the first work to present the latest results and findings on the new topic and hot field of planetary exploration and sciences, e.g., lunar surface iron content and mare orientale basalts, Earth's gravity field, Martian radar exploration, crater recognition, ionosphere and astrobiology, Comet ionosphere, exoplanetary atmospheres and planet formation in binaries. By providing detailed theory and examples, this book helps readers to quickly familiarize themselves with the field. In addition, it offers a special section on next-generation planetary exploration, which opens a new landscape for future exploration plans and missions. Prof. Shuanggen Jin works at the Shanghai Astronomical Observatory, Chinese Academy of Sciences, China. Dr. Nader Haghighipour works at the University of Hawaii-Manoa, USA. Prof. Wing-Huen Ip works at the National Central University, Taiwan.

In 1988, in an article on the analysis of the measurements of the variations in the radial velocities of a number of stars, Campbell, Walker, and Yang reported an - teresting phenomenon;the radial velocity variations of Cephei seemed to suggest the existence of a Jupiter-like planet around this star. This was a very exciting and, at the same time, very surprising discovery. It was exciting because if true, it would have marked the detection of the ?rst planet outside of our solar system. It was surprising because the planet-hosting star is the primary of a binary system with a separation less than 19 AU, a distance comparable to the planetary distances in our solar system. The moderatelyclose orbit of the stellar companionof Cephei raised questions about the reality of its planet. The skepticism over the interpretation of the results (which was primarily based on the idea that binary star systems with small sepa- tions would not be favorable places for planet formation) became so strong that in a subsequent paper in 1992, Walker and his colleagues suggested that the planet in the Cephei binary might not be real, and the variations in the radial velocity of this star might have been due to its chromospheric activities.