Part of the Scholastic Science Vocabular Readers 6-book series for the solar system - which includes: Stars and Constellations by Elizabeth Bennett The Earth by Megan Duhamel The Moon by Lydia Carlin The Planets by Jeff Bauer The Solar System by Jeff Bauer The Sun by Justin McCory Martin
Each of the books includes three chapters and then a Glossary and Comprehension Questions page in the back.
Each page of The Planets is devoted to a planet and shares one piece of information about it. Nothing groundbreaking. Basically what you expect for a first-to-second grade science vocabulary reader.