"Until 1990, no one could say for certain that planets existed beyond our solar system. Today, thanks to unprecedented advancements in technology, astronomers have found more than 5,000 of these exoplanets. Some are Earth-sized, some orbit a sun-like star, and some are rocky rather than gaseous. Could any of them hold life as we know it? Full-color photographs and engaging, age-appropriate text let students explore the exciting field of exoplanet study. A glossary of terms is provided to help expand readers' scientific vocabulary"--