More than 90 percent of the universe's 70 billion trillion suns are burning through their nuclear fuel in steady, predictable fashion. But when cosmic violence does unfold—colliding galaxies, solar storms, and gamma ray bursts —it changes everything. Likewise, here on Earth, existence as we know it is fragile, always vulnerable to biological disasters, asteroid impacts, and climate upheavals. Guiding us through the chaos, the author of The Sun's Heartbeat discusses cosmic rays, the explosive birth of our moon, and the ways that humanity has harnessed cataclysmic energy for its gain.