Michael Sabatino 
20 Fun Facts About Galaxies [PDF ebook] 

The Milky Way, a galaxy about 100, 000 light-years across, is our cosmic neighborhood. Scientists once thought the Milky Way was the only galaxy in the universe, but we now know it’s just one of billions. By studying galaxies and the stars and planets they contain, scientists have learned much about the universe and how it formed. Readers will be amazed when they see the stunning cosmic images of galaxies. Graphic organizers and accessible scientific text help make this volume an informative, enjoyable read.