Kirk Johnson

Renowned paleontologist Kirk Johnson takes us on an epic adventure through time at the polar extremes of our planet. Following a trail of strange fossils found in all the wrong places—beech trees in Antarctica, hippo-like mammals in the Arctic—Johnson uncovers the bizarre history of the poles, from miles-high ice sheets to warm polar forests teeming with life. What caused such dramatic changes at the ends of the Earth? And what can the past reveal about our planet’s climate today—and in the future?

In a race against developers in the Rocky Mountains, paleontologists uncover a unique fossil site packed with astonishingly well-preserved bones of mammoths, mastodons, and other giant extinct beasts. The discovery opens a highly focused window on the vanished world of the Ice Age in North America.

Travel back 66 million years ago when a meteor struck the Earth, wiping out three-quarters of all life on the planet. What happened in those first hours? Why did some creatures survive while nearly all others perished? Using computer graphics and real-world recreations, National Geographic reveals the likely effects of the catastrophic impact that changed the world forever and examines who won, who lost, and why.

The walrus is one of the Arctic’s most enigmatic animals. With three-foot long tusks and a droopy mustache, everyone knows what these marine mammals look like, but few ever see them in the wild. Most of the world’s walrus, about 250,000 of them, live in the frigid seas between Russia and Alaska. This film documents an Arctic adventure to uncover the hidden lives of these lumbering giants and the threats they face as climate change shrinks the sea ice. What kind of future lies ahead for walruses in the wild?

Thousands of footprints stretch for miles across New Mexico’s White Sands National Park, capturing moments when Ice Age humans encountered now-extinct beasts, including enormous ground sloths and mammoths. What can these footprints reveal about the peopling of the Americas and what life was like at the end of the last Ice Age?

Ranger Megan Patel loses her brother, Daniel, under mysterious circumstances. Struggling to understand how he died, she finds herself alone, venturing into the vast pine forest. However, as she follows the trail of her brother into the woods, the trees begin to change and shift around her. Soon Megan arrives in places without any recollection of how she got there. Almost as if something is pulling her deeper into the woods. Something dark and dangerous, that Megan might not be able to escape.

Mighty, elemental forces molded North America—fiery eruptions, titanic floods, the grinding of great ice sheets, and massive impacts from space all shaped our homeland. This film unfolds in a forgotten world that existed long before our own, crossed by long-lost mountain ranges, deserts the size of Africa, and vast inland seas spanning the length of the continent. Explore beloved landmarks like the Grand Canyon and Niagara Falls from the inside out as we witness the clash of nature’s creative and destructive forces. This spectacular road trip through a tumultuous deep past explores three fundamental questions: How was the continent built? How did life evolve here? And how has the continent shaped us?

PBS' premier science series helps viewers of all ages explore the science behind the headlines. Along the way, NOVA demystifies science and technology, and highlights the people involved in scientific pursuits.

Journey with Kirk Johnson to Yellowstone, where wolves, grizzlies, beavers and Great Gray owls survive one of the greatest seasonal changes on the planet. As the temperature swings 140 degrees, cameras capture how the animals cope.