What is a galaxy? Readers will learn the answer in this book! They will discover different types of telescopes and how their development has changed what scientists know about these giant marvels. Readers will also be introduced to other massive objects in the universe, such as star systems, planets, and the International Space Station. Aligned to Common Core Standards and correlated to state standards. A&D Xtreme is an imprint of Abdo Publishing, a division of ABDO.