To demonstrate the stunning beauty and overwhelming power of the Earth, Dr. Iain Stewart climbs into the crater of an active volcano in Ethiopia, jets into the stratosphere, climbs the frozen crests of the Alps, races the tide at the Amazon basin, dives into underwater caverns in Mexico, and generally enjoys himself to no end. His infectious enthusiasm is hardly necessary, though; Earth: The Biography (formerly The Power of the Planet) is five episodes of phenomenal images and fascinating information about how our planet formed and the potent yet delicate balance of life. Stewart, the program's host, seems destined to become the Carl Sagan of geology; his cheerful Scottish accent (he sounds like he walked out of Trainspotting) is just waiting for a catchphrase like "billions and billions" to make him a household name. Earth: The Biography juxtaposes things gigantic (tectonic plates) and teeny-tiny (plankton) while gracefully explaining the crucial role each plays in making the world habitable for life as we know it. There's even surprising humor, like demonstrating the ocean's currents through the movement of 29,000 plastic ducks that were swept overboard in a storm, or how the first thing jet pilot Joe Kittinger does, after successfully parachuting from the highest point in the stratosphere anyone has ever jumped (including 15 minutes of free fall), is light up a cigarette. Add in some CGI models of prehistoric beasts and volcanic activity, and you've got a completely addictive examination of the Earth in all its majesty. --Bret Fetzer