Follow the young life of an adorable polar bear cub who beat the odds to not only thrive but become one of the most famous bears in the world. Learn how a caring Berlin zookeeper takes care of him, and of how a trio of polar bear newborns and two orphaned brown bears get into all sorts of mischief.

They were pioneering warriors, expert seafarers, and colonists of the North Atlantic realm. The Vikings even claimed in their sagas to have reached America. Now, renowned archaeologist Sarah Parcak uncovers new clues about their legendary expeditions and settlements.

See the world through the eyes of nature's fastest animal: the peregrine falcon. Though once endangered in the US, this spectacular predator is now thriving again in American cities and on every continent but Antarctica. Join expert Lloyd Buck as he trains a captive peregrine and puts its hunting skills to the test. What's the secret behind the peregrine falcon's blistering speed?

In 1986 a catastrophic blast, 400 times more potent than the Hiroshima bomb, blew the lid off Chernobyl's Reactor No. Four, igniting fires that burned for days and sending a radioactive cloud across Europe. Ill-equipped workers heroically sealed the smoldering reactor in a concrete sarcophagus, but the hastily constructed shelter was only built to last 30 years. Now, 30 countries have come together to pay for a 25,000-ton steel shelter which will...