NOVA - Season 52

For decades UFOs have captivated the public, even as many scientists saw them as too taboo to investigate. Now, after highly publicized sightings of unidentified objects by Navy pilots, UFOs are moving out of the shadows and into the light, as NASA pledges to study them scientifically. So what does science have to say? Though some are identified as balloons or drones, weather phenomena, or optical illusions, others remain mysterious. Could they be the result of secret new technology developed by other governments – or our own? And what would it take for alien engineers to traverse vast distances to send probes or visit Earth from other solar systems? Explore the evidence, as astrophysicists and engineers use new technologies to investigate the strangest objects in our skies.

In New York City, a team of elite designers, engineers, and construction workers are on a mission to build the ultimate airport. The new LaGuardia is America's first new airport in more than 25 years and cost more than $8 billion to build. Over the course of eight years, 7,000 workers must rebuild the old airport to create a brand new, fully connected facility that can handle more than 34 million passengers every year. It takes 72,000 tons of steel and almost 600,000 tons of concrete to construct this engineering marvel, and the team has to battle extreme weather, complex geology, and massive machines. Follow their ups and downs in the extraordinary race to build a new, world-class airport on the site of one of America's busiest aviation hubs.

Contrary to popular belief, dinosaurs never went extinct. They're still alive among us – in the form of birds! Birds are the only dinosaurs that survived the cataclysmic mass extinction caused by an asteroid the size of Mt. Everest crashing into Earth about 66 million years ago. The big question is: How? How did birds manage to not only live through the apocalypse, but also go on to diversify and populate every corner of our planet? Now, rare fossil discoveries are revealing the secrets of bird evolution going back more than 100 million years, telling the story of how some resilient feathered dinos persevered and transformed into the vast array of colorful bird species that fill our skies today.

An archaeological detective story opens a door into an extraordinary moment in the history of Ancient Egypt, as the discovery of a long-lost cemetery not far from King Tut's tomb shines a light on an often-overlooked Egyptian kingdom. Treasures emerge revealing details of a unique period about 2,700 years ago, when kings from Nubia – present-day Sudan – conquered Egypt and shifted the status of Egyptian women, giving them remarkable power. Archaeologists and historians reveal how the ascent of The God's Wife of Amun lifted some women to the highest echelons of religious, political, and financial power in the ancient Egyptian empire.

For over two centuries, archaeologists have hailed Pompeii as a sophisticated city at the heart of an advanced ancient civilization. But a series of new excavations is painting a much more complex picture of the city tragically buried by the eruption of Mount Vesuvius in 79 CE. New archaeological finds – including 2,000-year-old lines of graffiti, human remains, and artifacts from ancient homes and businesses – are revealing a city of both staggering wealth and extreme poverty, dependent on slavery, and riven by political conflicts, violence, and riots. Before Vesuvius rumbled, the jewel of the ancient Roman Empire hid a very dark side.

On March 26, 2024, the world collectively gasped as a massive container ship, the Dali, lost control and plowed into the landmark Francis Scott Key Bridge in Baltimore. The busy four-lane bridge suffered a catastrophic collapse and crashed into the Patapsco River. Six highway workers were killed, and the Port of Baltimore – a crucial link in the global shipping chain on the Eastern Seaboard of the United States – was blocked by thousands of tons of twisted steel and concrete. How did a modern ship lose all power and propulsion? And why did the bridge fail so catastrophically? Follow the high-stakes rescue and recovery, the efforts to reopen the port, and the investigations into what went wrong and how many other crucial bridges are at risk.

In 1775, a ragtag army of farmers and tradesmen went to war against the most powerful army in the world, ultimately winning American independence. What military technologies did the American colonies use in their fight for freedom, and how did they help propel them to one of history's most unlikely victories? Archaeologists and historians uncover the real stories of innovation, skill, and strategy that determined the outcome of important battles. From the Brown Bess musket to the world's first military submarine, get a closeup look at the powerful and sometimes ingenious weapons that helped the colonies win the war.

Can forests help cool the planet? Follow scientists working in spectacular forest landscapes in Costa Rica, Brazil, Australia, and beyond as they try to untangle complex networks of trees, fungi, and creatures large and small – all in a quest to tackle the twin threats of climate change and species extinction.