Legendary oceanographer and Explorer at Large Bob Ballard is best known for his historic discoveries of hydrothermal vents, the sunken R.M.S. Titanic, and numerous other contemporary and ancient shipwrecks around the world. However, when asked about his greatest discovery, Ballard always says, “The one I’m about to make.” Today, on his birthday, we celebrate his efforts and contributions that have inspired generations of ocean explorers. | National Geographic Society