Geologists think these iconic chalk cliffs hold an extraordinary secret.

Devastating hurricanes struck the U.S. mainland and Caribbean islands in 2017. But they weren’t the first. The Great Hurricane of 1780 took nine days to blast its way across the Caribbean, killing at least 20,000—the highest known death toll of any single weather event in history. What made this superstorm so deadly?

Hurricanes bring wind, rain, and destruction—but how do they form?

The Supreme Court is hearing a gerrymandering case. Mathematicians are watching closely.

NOVA follows a team of volcano sleuths as they embark on a worldwide hunt for an elusive volcanic mega-eruption that plunged medieval Earth into a deep freeze. They look for the signature of a volcanic eruption big enough to have blasted a huge cloud of ash and sulfuric acid into the atmosphere, which chilled the entire planet. Across the globe, it turned summer into winter.

Researchers try to prove the existence of a 13th century volcanic eruption using ice.

Discover how Beijing’s Forbidden City, the largest palace complex in the world, has survived 500 years of earthquakes

The Forbidden City is the world’s biggest and most extravagant palace complex ever built. For five centuries, it was the power center of imperial China and survived wars, revolution, fires, and earthquakes. How did the Ming Emperor’s workforce construct its sprawling array of nearly 1,000 buildings and dozens of temples in a little over a decade?

What are intercontinental ballistic missiles (ICBMs), and why are they hard to shoot down?

Once upon a time, knighthood was serious business, and for countless medieval fighters, their armor was what stood between life and death. NOVA challenged a blacksmith and master armorer to recreate parts of an elite armor. We trace their journey as they rediscover centuries-old metalworking secrets, then put their new armor to the ultimateultimate test against a period musket.

Knights and firearms clashed on the battlefield for over 200 years. Did some of these warriors have armor strong enough to stop bullets?

Hurricane Harvey broke continental U.S. records. Here's how cities can be better prepared.

Stonehenge is the grandest and most enigmatic of Europe’s prehistoric monuments, and has inspired countless theories to explain who built it and why. Join NOVA as we reveal intimate details of the Stonehenge people and why their power began to fade soon after they raised the mighty stones.

On September 15, 2017 NASA destroyed Cassini—on purpose. Why kill a multibillion-dollar spacecraft?

Relive Cassini's greatest hits from its 13 years studying Saturn.

Cassini, a brave explorer that was dispatched to study a distant ringed world, has died.

Is there life beyond Earth? The solar system's ocean worlds might be the most promising places to look.

Aiming to skim less than 2000 miles above the cloud tops, no spacecraft has ever gone so close to Saturn, and hopes are high for incredible observations that could solve major mysteries about the planet’s core. Join NASA engineers for the tense and triumphant moments as they find out if their bold re-programming has worked, and discover the wonders that Cassini has revealed over the years.

Why don't solar eclipses happen every month? After all, you only need three things to make a solar eclipse: the Sun, the Earth and the Moon.