Covering more than 30 percent of the Earth’s surface, the Pacific Ocean is the largest water mass on the planet. With a surface area of more than 155 million square kilometers (60 million square miles), this ocean basin is larger than the landmass of all the continents combined. Additionally, it contains almost twice as much water as the world's second largest body of water, the Atlantic Ocean.
The Pacific is also our planet’s deepest water body, with an average depth of approximately 4,000 meters (13,000 feet). The deepest place on Earth, known as Challenger Deep, extends to a depth of more than 11,000 meters (36,000 feet) and is found in the Mariana Trench, in the Pacific.
Holding more than half of the Earth's open water supply, the Pacific Ocean was named by explorer Ferdinand Magellan in 1520, who called this body of water "pacific," due to the calmness of the water at the time ('pacific' means peaceful).