S1, E1: There are billions of stars in the Universe, but one alone dominates our celestial neighborhood, the Sun. It's so large that within its boundaries you could fit one million Earths, and so powerful that each second it churns out as much energy as one billion one-megaton hydrogen bombs. The Sun is the massive engine that drives our solar system, providing the energy that makes life on Earth possible, but it also rages with violent storms and explosions that can threaten our planet. With some experts predicting that we are headed for the most violent period of solar activity in modern history, it's never been more important to understand the Secrets of the Sun.