NOVA - Season 53

Imagine a time when Earth was a molten, volcanic wasteland, heavily bombarded by colossal asteroids. We've long feared these cosmic impacts as destroyers of life, but what if they were the key to our very existence? Explore a revolutionary theory suggesting that these violent collisions provided the essential ingredients – water, minerals, and energy – needed for life to ignite on our planet. Discover how scientists are unearthing evidence from lunar rocks and ancient impact craters, revealing that the very objects known for extinguishing life might have actually sparked it.

Uncover the lost secrets of a once-mighty empire. The city of Angkor, the seat of the great Khmer Empire in Southeast Asia for 500 years, was once the biggest city in the world. For centuries, this incredible civilization flourished, building the largest religious monument on Earth, Angkor Wat, and mastering urban engineering in a challenging landscape. But then it was mysteriously abandoned, swallowed by the jungle. Now, cutting-edge technology and new discoveries are finally revealing how this astounding empire rose to global prominence – and what likely led to its devastating collapse. Follow a scientific detective story that is challenging everything we thought we knew about this ancient metropolis.

Imagine a world where your furry best friend could tell you exactly what they're thinking. A growing number of dog owners claim this is already happening, thanks to innovative word buttons that seem to unlock a new realm of canine communication. But are these dogs truly understanding what we're saying — and talking back? Are they really thinking creatively, applying words in new contexts? Or is this just clever conditioning? To find out, scientists are conducting the largest animal communication study in history, analyzing millions of button presses from thousands of dogs worldwide. Witness astonishing moments that challenge our assumptions about animal intelligence, from dogs that seemingly engage in conversations to those who learn new words with incredible speed. Prepare to question everything you thought you knew about the minds of dogs and discover just how far their linguistic abilities might stretch.

Uncover the surprising ancient origins of mammals, a story that began long before the dinosaurs' reign. Surveying Earth's tumultuous past reveals how some of our earliest ancestors, the therapsids – creatures that looked like reptiles but were starting to develop mammalian traits – survived multiple global catastrophes. Through remarkable adaptations like burrowing and the emergence of warm-bloodedness, they forged a lineage that persevered against all odds. Fascinating fossil clues and cutting-edge science reveal how a small, resilient group of animals faced extinction events, outlived giants, and ultimately gave rise to the diverse world of mammals we know today, including us.

On a remote hillside in modern-day Turkey sits Gpbekli Tepe, the oldest temple on Earth. For centuries, archaeologists believed it was a religious center built by nomadic hunter-gatherers before the rise of civilization. But groundbreaking new evidence reveals that a sophisticated community of settled hunter-gatherers, not nomads, lived here year-round for centuries. This startling discovery could be the missing link in humanity's momentous transition from hunting to farming. Follow experts as they use new digs and shattered skulls to piece together a captivating story that could forever change our understanding of the roots of civilization.

A half-century after American astronauts walked on the Moon, NASA and its international partners are taking the dream of Apollo a giant step further. In the coming years, the Artemis missions – named after Apollo's twin sister in Greek mythology – aim to bring astronauts back to the Moon and establish a lunar space station for scientific and commercial exploration. Follow the four members of the Artemis II crew as they embark on a perilous 10-day journey to orbit the Moon, venturing beyond Earth orbit for the first time since Apollo and farther into the Solar System than any humans have gone before. And get an inside look at the preparations needed to overcome the extreme engineering challenges of human-crewed spaceflight, all the way from launch to splashdown.

Correction: This film previously stated that the four engines of the core stage generate 8.8 million pounds of thrust at liftoff. In fact, that much thrust is generated by the entire rocket including the boosters, not the core stage alone. The film has been updated accordingly.

An invisible, unpredictable atmospheric force is wreaking havoc across the globe, sinking superyachts and bringing down planes. Follow scientists as they race to understand these catastrophic weather events, exploring how they form, what causes their devastating impacts, and how we might someday learn to predict them. From high-tech simulations and drone expeditions into thunderclouds to possible links with climate change, join investigators on the cutting edge of research to discover what's truly behind these terrifying "rain bombs" and how we can protect ourselves from their growing power.

The United States has experimented with democracy for 250 years, but our system of government was once a radical idea, born in ancient Greece. Ravaged by civil war and tyranny 2,500 years ago, the city of Athens forged a revolutionary new system that gave power to the citizens. Witness the archaeological quest to unearth the ingenious tools and pivotal moments that shaped this unprecedented experiment in self-government. From mysterious fragments of ancient voting machines to mass graves and dramatic assassinations, discover the dark secrets and innovative solutions that defined the world's first direct democracy. What enduring lessons can this surprising historical journey offer us today?