NASA's Kepler telescope discovers thousands of exotic new worlds, some of which may even be able to harbor life.
Britain develops defenses against German zeppelins that drop bombs on London during World War I.
Meteorologists dissect Typhoon Haiyan, which stirred up 200-mph winds and a two-story-high storm surge; what made it so destructive and why the Philippines were so vulnerable to such a violent storm.
Scientists investigate bodies unearthed from Ireland's bogs to determine who they were and why their deaths were so violent.
Maintenance workers stumble upon six caverns stacked with hundreds of skeletons in the Catacombs of Rome.
Using period tools and techniques, bricklayers build an experimental mini-Duomo to try to determine how Filippo Brunelleschi built the dome that crowns Florence's great cathedral of Santa Maria del Fiore.
Problem-solving birds include a cockatoo that picks locks; a wild crow solves an eight-step puzzle; a raven solves a puzzle box so fast it is captured with high-speed photography.
The high-powered senses of dogs, sharks and birds.
The smartest animals seem to be the ones living in complex social groups, like dolphins, elephants and apes.
Researchers in Australia and the U.S. investigate the hunting instincts of the great white shark.
A group of British officers devise a plan to escape from Colditz Castle, a prisoner of war camp controlled by the Nazis in Germany.
Dive teams, submersibles and underwater robots search the seabed bordering the beaches of Normandy, France, for Allied ships that sank from German shellfire, mines and torpedoes.
The science behind vaccinations; tracking epidemics; the human costs of refusing a vaccine.
Scientists in the fast-paced world of cryptography work to forge unbreakable codes to keep data safe.
Technology fails to track a Malaysian Airlines Flight MH370 when it mysteriously disappears.
Medical teams in West Africa cope with a rising number of Ebola victims; scientists race to test vaccines in hope of finding a cure.
A re-creation of an 18th-century hot-air balloon flight uses tools and materials available at that time.
The role of early flying machines in World War I.
The discovery of new fossil bones in a Moroccan cliff reopens the investigation into a creature called the Spinosaurus.
High-action experiments and 3-D technology provide insight into how China's terracotta army was made.
Scientists investigate the specific local geological and climatic factors behind the 2014 collapse of a hillside in Oso, Wash.
Neil Armstrong's family and friends recall his achievements before and after the Apollo 11 moon landing, including his role in the inquiry into the Challenger disaster and his efforts to encourage young people to explore space and flight.