Scientists break down the reasons why days are getting shorter—and the mystery they're still trying to solve about Earth's ...

Earth’s temperature cooled down, rain fell for centuries. Oceans formed. Longer than human history, the creation of oceans—all this water that we can float on, fly ...

Stream the special on National Geographic's YouTube channel and ABC's Localish Network starting on April 18, and catch it on local ABC TV stations, ABC.com, and Hulu Live during Earth Week.

WASHINGTON -- National Geographic is marking World Oceans Day by recognizing the Southern Ocean as the Earth's fifth ocean. While all of the planet's ocean waters are interconnected, National ...