The Sun, Mercury, and Venus explores the innermost solar system and the importance of the Sun's energy on orbiting bodies. As the closest planet to the Sun, Mercury is the least visited of terrestrial planets and is difficult to see because it is always close to the Sun from the Earth's perspective. This volume also covers the geological characteristics of Venus in relation to the Sun and the rest of the solar system.

Jupiter and Saturn examines what is known and still unknown about Jupiter 200 years into the development of telescopes and astronomy, as well as Saturn's interior structure, heat production, and magnetic field. This volume also explores the orbital movements of Jupiter in the solar system and its internal and external composition, movements, and temperatures, as well as Saturn's extensive ring system.

Mars discusses the fundamental facts concerning this mysterious planet, including its mass, size, and atmosphere, as well as the various missions that have helped planetary scientists document its geological history. This volume also describes Mars' seasons, including their surface effects on the planet and how they have changed over time, as well as what is known and inferred about the composition and structure of the interior of Mars.