"NASA has confirmed the existence of 5,000 exoplanets (planets that lie outside of our solar system), and that number is growing! Exoplanets, the first book of its kind for kids, is a visually packed guide to the exoplanets of our universe. You'll learn the four main types of exoplanets, techniques scientists use to discover them, the probability of finding life as we know it beyond Earth, plus detailed information about dozens of some of the most fascinating exoplanets discovered so far, from water worlds to planets that are literally evaporating!"-- Page 4 of cover.