This book’s genre is science nonfiction and written by Paul P. Sipiera. It’s about black holes, scientist, and other things in space. Black holes are made by a star. The star blows up. It forms a supernova. Also, scientist make super cool discoveries in my book. Our galaxy is called the Milky Way galaxy. There are many galaxies in the universe. The main characters are the black hole scientist that study black holes. These scientist also discover facts about mass, gravity, and our universe. Two key events that happened in the book that added to the plot is a supernova, and scientist. Supernovas added to the plot because when the author described a supernova it kept on popping up in my book. Scientists added to the plot because scientist kept on discovering new stuff. On page 21, one of the scientist did not know that any object can turn into a black hole. But, he changed his knowledge of the discovery when he learned the object has to become small enough and dense enough, and it can change into a black hole. This was from Albert Einstein’s theory of relativity. One unanswered question that I’d like to ask the author is, “What is inside a black hole?” What I enjoyed the most about the book is if you were on one of Mars's moons you can throw a baseball and it would most likely orbit Mars’ moon. I would recommend this book because you can learn so much about outer space. You can learn about mass, gravity, black holes,etc. If you enjoy reading and learning about space you would enjoy this book.