Nova: Ancient Earth Season 1, Episode 5: Ancient Earth: Humans

Ancient Earth: Birth of the Sky

Today, Earth is enveloped by a thin veil of gas, a narrow band of atmosphere that protects a world covered in lush green vegetation, deep blue oceans, and abundant life. But 4.5 billion years ago, Earth was a very different place: a hellscape of molten lava and barren rock, under relentless bombardment from meteors, and with no atmosphere whatsoever. So how did our familiar blue sky come to be? Breathtakingly realistic animations and a chorus of science experts reveal how the primordial inferno first gave rise to an orange-hued cauldron of toxic gasses that would be deadly to us today. Witness how the first drops of rain splashed down on the searing planet, setting the stage for the evolution of life. And discover how life itself helped create the air we all breathe today.

Ancient Earth: Frozen

Ancient Earth: Life Rising

For billions of years, life teemed in the oceans of planet Earth while the land was desolate and inhospitable. So how did life make the leap to land? Scientists explore how some of the earliest life emerged and invaded a barren, rocky landscape, eventually transforming it into a verdant, green world. Gripping visual effects reveal an alien landscape dominated by towering fungi before the arrival of plants. Witness how the first plants made landfall and partnered with fungi to create soil that would sustain them. And discover how, once life emerged on land, it fundamentally altered the very ground it grew on.

54 min

Ancient Earth: Inferno

252 million years ago, the most devastating mass extinction of all time abruptly wiped out around 90% of all species on Earth. The culprits were the biggest volcanic eruptions the world has ever seen, emitting some 700 thousand cubic miles of magma and rock. Volcanic gasses permeated the atmosphere and acidified the oceans while toxic gasses destroyed the ozone layer, bathing the planet in destructive UV radiation. The event—now called "The Great Dying"—came close to wiping out all life on the planet. Follow scientists as they piece together geologic evidence from the deep past and clues from today’s ecosystems to discover how life made it through and evolved into the astonishing variety we see around us today.

54 min