This book discusses twelve areas of active astronomical research, ranging from the nature of dark energy to the existence or otherwise of extraterrestrial civilizations, and devotes one chapter to each topic. Although astronomers tackle each of these questions using information gleaned from all possible wavelengths and sources (and this is emphasized throughout the book), in this work the author dedicates each chapter to a particular observational method. One chapter covers X-ray telescopes for investigating black holes, while another uses infrared telescopes to learn more about planetary information.