Stargazers have observed Mercury, Venus, and Mars–the other small, rocky planets in our solar system besides Earth–for thousands of years. More recently, we have begun to explore our neighbors in outer space via flyby spacecraft, probes, and rovers. Readers will learn how these expeditions have expanded our knowledge of these planets’ atmospheres, surfaces, features, and even potential for life. A must-read for anyone interested in discovering more about space exploration’s past, present, and future.