Presents information learned by past and present observers of Mars, the fourth planet from the sun, and briefly describes the scientific missions that have been sent there.

Briefly describes the surface features, internal composition, orbit, moons, and efforts to study the planet Neptune.

Briefly describes the discovery, composition, planetary motion, moons, and efforts to study the planet Uranus.

Briefly describes the surface features, composition, moons and rings, and efforts to study the planet Saturn.