Origins

The series' first hour, "Origins: Earth is Born," gives viewers a spectacular glimpse of the tumultuous first billion years of Planet Earth-a time of continuous catastrophe. Vivid animation lets viewers witness the traumatic birth of the moon from a titanic collision between Earth and an object believed to have been the size of Mars. Bombarded by meteors and comets, rocked by massive volcanic eruptions, and scoured by hot acid rain, the early Earth seems a highly improbable place for life to have taken root. Despite such violent beginnings, scientists have found new clues that life-giving water and oxygen appeared on our planet much earlier than previously thought.

Hour Two, "Origins: How Life Began," zeroes in on the mystery of exactly how it happened. Join the hunt for hardy microbes that flourish in the most unlikely places: inside rocks in a mine shaft two miles down, inside a cave dripping with acid as strong as a car battery's, and in noxious gas bubbles erupting from the Pacific ocean floor. The survival of these tough microorganisms suggests they may be related to the planet's first primitive life forms. Tyson deepens the search by investigating tantalizing and controversial chemical "signatures" of life inside three-billion-year-old rocks and meteorites found around the world.

In Hour Three, "Origins: Where are the Aliens?," Tyson explores such provocative questions as: would "ETs" resemble us or the creatures of science fiction? Are there "aliens" already amongst us on Planet Earth-brainy creatures whose intelligence is very different from our own? And are planets on which life can flourish rare or common in our universe?

Hour Four starts with a bang-the big bang in which everything began. "Origins: Back to the Beginning" explores how the colossal, mind-boggling forces of the early universe made it possible for habitable worlds to emerge. The clues begin with a race among scientists to capture lingering echoes of the big bang's ferocious energy in a microwave "whisper" from deep space. The race pits underdog astronomer Tony Readhead and his improvised detector in the high Andes against NASA scientists and their state-of-the-art satellite probe. Tyson shares his excitement with viewers as computer animation of the big bang's echo emerges on the screen. It's as close as we can get to a "photograph" of the primordial universe. Here we glimpse the seeds from which all the galaxies, stars, and planets eventually grew.