A record-setting triathlete dares to complete 50 Ironman races -- a 2.4-mile swim, a 112-mile bike ride, and a 26.2-mile run -- in 50 days in 50 states.
Many of the most popular taco styles have long, rich, little-known histories. Explore some of them in this eye-opening, mouth-watering food adventure.
Astrophysicists show how black holes might hold answers to how the universe evolved, leading to life on Earth and, ultimately, the human race.
During risky expeditions in an underwater cave, scientists unearth a 13,000-year-old skeleton to gain insight into the earliest known humans in America.
An international team of rescue workers race to save 12 young soccer players and their coach trapped in a flooded cave in Thailand.