The largest ocean on the planet is the Pacific Ocean. Covering approximately 63 million square miles, it spans from the Arctic in the north to the Southern Ocean in the south, and from Asia and Australia in the west to the Americas in the east. The Pacific Ocean not only contains more water than all the Earth's landmasses combined, but it also hosts a vast array of marine life and ecosystems, as well as significant geological features like the Mariana Trench, the deepest part of the world's oceans.