Currently, Asia is Earth's largest continent at approximately 17,300,000 square miles (44,806,812 sq km). Africa comes in second at about 11,700,000 square miles (30,300,000 sq km). However, Continental Drift Theory suggests that the continents have moved over the years through the process of plate tectonics. Many geologists believe that, during the Mesozoic era, all of the continents combined to form a supercontinent known as Pangaea which would have dwarfed the largest continent today. It is believed that Pangaea began to break up about 200 million years ago.
The Sargasso Sea is a region in the middle of the North Atlantic Ocean. Surrounded by ocean currents, it is the only sea on Earth which has no coastline. It is bounded on the west by the Gulf Stream; on the north, by the North Atlantic Current; on the east, by the Canary Current; and on the south, by the North Atlantic Equatorial Current.