The Planets: Inner Worlds

Hear Apollo astronauts and engineers tell the inside story of how the first mission to the moon, Apollo 8, pioneered groundbreaking technologies that would pave the way to land a man on the moon and win the space race.

Fifty years after humans first set foot on the moon, new scientific discoveries are fueling excitement for a return to the lunar surface -- this time, perhaps, to stay. Join the scientists and engineers working to make life on the moon a reality.

Retrace Einstein's thought experiments as NOVA reveals the simple but powerful ideas that reshaped our understanding of gravity, illuminating the theory of general relativity-and Einstein's brilliance-as never before.

A deadly recipe threatens the survival of countless creatures throughout Earth's oceans. We've known for years that oceans absorb about a quarter of the carbon dioxide in our atmosphere. With carbon emissions sharply rising, the silent killer is entering the seas at a staggering rate - raising the oceans' acidity. As a result, the skeletons and shells of marine creatures that form the foundation of the web of life are dissolving.

See the epic 3-billion-year story of how our continent came to be. From palm trees that once flourished in Alaska to huge eruptions that nearly tore the Midwest in two, discover how forces of almost unimaginable power gave birth to North America.

The rocky planets - Mercury, Venus, Earth and Mars - were born of similar material around the same time, yet only one supports life. Were Earth's neighbors always so extreme? Is there somewhere else in the solar system where life might flourish?

Mars was once a blue water world studded with active volcanoes. But when its magnetic field and protective atmosphere faded, it became the frozen desert planet we know today. With so many necessary elements in place, did life ever form on Mars?

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Jupiter's massive gravitational force made it a wrecking ball when it barreled through the early solar system. But it also shaped life on Earth, delivering comets laden with water - and perhaps even the fateful asteroid that wiped out the dinosaurs.

NASA's Cassini explores Saturn for 13 years, looping through its icy rings and flying by its moons. The probe captures stunning ring-moon interactions, but when it finds the ingredients for life on the moon Enceladus, a bittersweet decision is made.

Discover the surprising intertwined story of life and the landscape in North America-from origins to iconic dinosaurs to giant marine reptiles swimming in an ancient sea that once split the continent in two.

From Ice Age to oil boom, discover the challenges faced and the wealth uncovered as humans take over the continent. How did we turn rocks into riches? And what catastrophic natural disasters could threaten the civilization we've built?

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe. An amazing new trove of fossils reveals how mammals took over, ultimately evolving into the huge array of species, including us, that rule Earth today.