The Best Episodes Written By Thomas Lucas

Long ago, from the fires of our Sun's birth, twin planets emerged: Venus and Earth. Nature draped one world in the greens and blues of life, while enveloping the other in acid clouds, high heat, and volcanic flows. Why did Venus take such a disastrous turn and Earth developed a vibrant biosphere?

Scientists, meteorologists and storm chasers try to uncover the secrets of F5 tornadoes, the largest, most powerful and most dangerous on Earth. Included are looks at how funnels form and the devastating 2003 tornado in Moore, Oklahoma, plus "tornado tourists," who pay companies to take them to the ferocious phenomena to see them first-hand.