Pacific Ocean
The Pacific Ocean is the largest of the Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

's ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...

ic divisions. It extends from the Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

 in the north to the Southern Ocean
Southern Ocean
The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...

 (or, depending on definition, to Antarctica) in the south, bounded by Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

 and Australia
Australia (continent)
Australia is the world's smallest continent, comprising the mainland of Australia and proximate islands including Tasmania, New Guinea, the Aru Islands and Raja Ampat Islands...

 in the west, and the Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

 in the east.

At 165.2 million square kilometres (64.1 million square miles) in area, this largest division of the World Ocean
World Ocean
The World Ocean, world ocean, or global ocean, is the interconnected system of the Earth's oceanic waters, and comprises the bulk of the hydrosphere, covering almost 71% of the Earth's surface, with a total volume of 1.332 billion cubic kilometres.The unity and continuity of the World Ocean, with...

 – and, in turn, the hydrosphere
A hydrosphere in physical geography describes the combined mass of water found on, under, and over the surface of a planet....

 – covers about 46% of the Earth's water surface and about one-third of its total surface area, making it larger than all of the Earth's land area combined.

1513    Spanish explorer Vasco Núñez de Balboa reaches what would become known as the Pacific Ocean.

1520    The Strait of Magellan, the passage immediately south of mainland South America, connecting the Pacific and the Atlantic Oceans, is first navigated by Ferdinand Magellan during his global circumnavigation voyage.

1520    After navigating through the South American strait, three ships under the command of Portuguese explorer Ferdinand Magellan reach the Pacific Ocean, becoming the first Europeans to sail from the Atlantic Ocean to the Pacific.

1610    Henry Hudson sails into what it is now known as Hudson Bay thinking he had made it through the Northwest Passage and reached the Pacific Ocean.

1793    Alexander Mackenzie reaches the Pacific Ocean becoming the first Euro-American to complete a transcontinental crossing of Canada.

1806    After traveling through the Louisiana Purchase and reaching the Pacific Ocean, explorers Lewis and Clark and their "Corps of Discovery" begin their arduous journey home.

1855    The first locomotive runs from the Atlantic Ocean to the Pacific Ocean on the Panama Railway.

1899    The United States takes possession of Wake Island in the Pacific Ocean.

1902    The Commercial Pacific Cable Company lays the first Pacific telegraph cable, from Ocean Beach, San Francisco to Honolulu, Hawaii.

1914    World War I: the first British Royal Navy defeat of the war with Germany, the Battle of Coronel, is fought off of the western coast of Chile, in the Pacific, with the loss of HMS Good Hope and HMS Monmouth.