The forces of nature make Earth a restless planet, but they also turned our ball of rock into a home for life. How did our planet's ingredients, the chemical elements, come together and take that first crucial step from barren rock to a living world?

Every weekday, NPR's Morning Edition has taken listeners around the country and the world with two hours of multi-faceted stories and commentaries that inform, challenge and occasionally amuse.

This week's San Francisco opera broadcast is Edgar Allen Poe's, "The Fall of the House of Usher," this Saturday, September 24 at noon on Classical 90.5 .