Ever since our species left Africa some 60,000 years ago, the urge to push beyond what’s known—to discover new lands and opportunities—has shaped human culture. And that impulse is still strong. As we celebrate the National Geographic Society’s 125th anniversary, we’re kicking off a year of stories about the new age of exploration. In this issue we consider the origins of our restless spirit; we examine new realms of life at the microscopic scale; we reach deep into the universe, searching for worlds like our own; we urgently document nature’s diversity, even as it vanishes before our eyes. Exploration is alive. (Source: National Geographic Channel)