Henry Louis Gates, Jr. helps singer Sammy Hagar and actor Ed O’Neill uncover their hidden roots, revealing scandals and secrets that their ancestors went to great lengths to conceal. Traveling from criminal underworlds to Civil War battlefields, they explore the meaning of family bonds—meet heroes and villains—and celebrate the virtue of accepting one’s relatives, whoever they may be.

Astronaut and robot companion. NASA's goal to send astronauts to Mars would require a three-year absence from Earth, during which communication in real time would be impossible due to the immense distance. Meet the psychologists whose job is to keep astronauts mentally stable in outer space, as they are caught between their dream of reaching new frontiers and the basic human need to stay connected to home.

Known only by her research number, Grizzly 399 has been a fixture in Grand Teton National Park since 2007, becoming the world’s most famous grizzly bear. Now 399 is raising four new cubs in the face of human encroachment, a warming climate and the threat of losing protection under the Endangered Species Act.