Black holes in space are a phenomena that are hard to study.  Formed when a large star burns out, the gravity pulls all surrounding matter, even light, in.  Scientists study this occurrence through telescopes both on earth and in space.  The photographs and illustrations are labeled and captions provide additional information.  The text is large and facts about this vast topic are basic.  Some vocabulary may be unknown to young readers but are explained on the page.  A few include pronunciation cues.  Theories about black holes were first suggested in the late 1700s.  Facts are still being gathered today.  A glossary and index are located  in the back.  An Abdo website provides supplemental and updated information on their Book Links page.  Young readers interested in space will enjoy this introduction to black holes.  Many stated details will lead to further investigations.  Recommended for elementary libraries.