Eclipses have stunned, frightened, emboldened and mesmerized people for thousands of years. They have been thought of as harbingers of evil as well as a sign of the divine. An amazing phenomena unique to Earth, they have provided the key to much of what we now know and understand about the sun, our moon, gravity, and the workings of the universe. Dvorak provides explanations as to how and why eclipses occur-- as well as insight into the forthcoming eclipse of 2017 that will be visible across North America.