K-Gr 4—This unique series provides a comprehensive look at space exploration, with topics ranging from the features of the solar system to the life of an astronaut to a hypothetical look at life on Mars and finding an Earth-like planet. Each title effectively conveys an immense topic in an accessible and entertaining way, relying on a controlled vocabulary and five to six simple sentences per page. Appealing page layouts, featuring full-color photographs, as well as labels and fun facts, are eye-catching and support comprehension. Each entry contains a relevant science experiment, such as designing a tiny spacecraft and building a Mars habitat. Text features include bold words highlighting important vocabulary (orbits, satellites), an index, and a visual glossary. VERDICT Written at a second grade reading level, this is an excellent STEM series for early elementary students in a general collection, as well as for older hi-lo readers.