Solar System Planets and Exoplanets provides a current viewpoint of planetary systems. The solar system’s planets and exoplanets are addressed in an overview manner, and specific space probe data are used to provide a current state of knowledge of Venus and Mars. Recent Mars data and associated observations are addressed in several chapters. Of particular interest are data that suggest the possibility that life could have existed on the planet’s surface during its past when Mars’ atmosphere was wetter and denser. The search for life on Mars is one of the main objectives of space missions, and it is an ongoing theme of this book. Key to the existence of life is the evolution of the radiation output of the Sun that is discussed and projected into the future. Space probe data related to the Asteroid Belt is also presented. Technological advances in terms of operating aircraft on Mars and propulsion systems provide useful commentary regarding future innovations that will enhance upcoming space missions and the search for life.