Southern Ocean officially recognized by National Geographic

National Geographic announced Tuesday that it is officially recognizing the Southern Ocean as the Earth's fifth ocean. The announcement was made to coincide with World Oceans Day.

The Southern Ocean is a vital home for marine ecosystems and a focal point for the southern hemisphere. It directly surrounds Antarctica, extending from the continent's coastline to 60 degrees south latitude, excluding the Drake Passage and Scotia Sea. The ocean's borders touch three of the four other oceans that exist on Earth — the Atlantic, Indian and Pacific.  But what makes the Southern Ocean different from the others is that rather than being largely defined by the land that surrounds it, this body of water is unique because of a current that lies within.