In the remote mountains of China, scientist come closer to understanding the origins of flowers.

English archers had their longbows, Old West sheriffs had their six-guns, but Japan’s samurai warriors had the most fearsome weapon of all: the razor-sharp, unsurpassed technology of the katana, or samurai sword. In this program, NOVA probes the centuries-old secrets that went into forging what many consider the perfect blade. Fifteen traditional Japanese craftsmen spent nearly six months creating the sword that NOVA follows through production, from smelting the ore to forging the steel to sharpening the blade to a keen edge capable of slicing through a row of warriors at one swoop.

NOVA takes you inside a very special ER to witness the efforts of wildlife veterinarians as they fight to save their animal patients as well as to uncover the cause of a mysterious neurological illness plaguing marine mammals like California sea lions and harbor seal pups. Part emergency room, part rehab facility, and part research lab, the Marine Mammal Center in Sausalito, California means the difference between life and death for sick and injured ocean animals. Not only are the animal patients endearing, they are also sending us an urgent message about the health of our oceans.

An examination over whether a comet struck the Great Lakes region 12,900 years ago, and whether it caused the extinction of such mega-creatures as the woolly mammoth and the saber-toothed cat in North America. Also included is the discovery of nano-diamonds which are created by heat and objects from space.

Can emerging technology defeat global warming? The United States has invested tens of billions of dollars in clean energy projects as our leaders try to save our crumbling economy and our poisoned planet in one bold, green stroke. Are we finally on the brink of a green-energy "power surge," or is it all a case of too little, too late?

From solar panel factories in China to a carbon capture-and-storage facility in the Sahara desert to massive wind and solar installations in the United States, NOVA travels the globe to reveal the surprising technologies that just might turn back the clock on climate change. NOVA will focus on the latest and greatest innovations, including everything from artificial trees to green reboots of familiar technologies like coal and nuclear energy. Can our technology, which helped create this problem, now solve it?

On June 6, 1944, the Allies launched the biggest armada in history to invade the Normandy beaches and liberate Europe from the Nazis. In less than 24 hours, more than 5,000 ships crossed the English Channel, along with thousands of tanks and landing craft and nearly 200,000 men. Throughout the operation, hundreds of ships sank running the gauntlet of mines and bunkers, creating one of the world's largest underwater archaeological sites. Now, NOVA has exclusive access to a unique collaboration between military historians, archaeologists, and specialist divers to carry out the most extensive survey ever done of the seabed bordering the legendary beachheads. Dive teams, submersibles, and underwater robots will discover and identify key examples of Allied craft that fell victim to German shellfire, mines, and torpedoes, using the latest 3D-mapping tools to plot the relics on the sea floor. Highlighting the ingenious technology that helped the Allies overcome the German defenses, and featuring first-hand accounts from Allied veterans who have returned to the site of this epic battle to share their harrowing stories, "D-Day's Sunken Secrets" unfolds a vivid blow-by-blow account of the tumultuous events of D-Day and reveals how the Allies' intricate planning and advanced technology assured the success of the most ambitious and risky military operation ever launched.

Four and a half billion years ago, the young Earth was a hellish place—a seething chaos of meteorite impacts, volcanoes belching noxious gases, and lightning flashing through a thin, torrid atmosphere. Then, in a process that has puzzled scientists for decades, life emerged. But how? NOVA joins mineralogist Robert Hazen as he journeys around the globe. From an ancient Moroccan market to the Australian Outback, he advances a startling and counterintuitive idea—that the rocks beneath our feet were not only essential to jump-starting life, but that microbial life helped give birth to hundreds of minerals we know and depend on today. It's a theory of the co-evolution of Earth and life that is reshaping the grand-narrative of our planet’s story.