Antarctica is Earth’s southernmost continent. About the size of the United States and Mexico combined, it is almost entirely covered by a thick ice sheet that gives an average elevation of 8,200 ft (2,500 m), the highest of any continent. This ice sheet contains 90 percent of the planet’s land ice, which represents 70 percent of the Earth’s fresh water.
Known as “the continent of science,” this vast natural laboratory is protected from military and commercial use by the Antarctic Treaty. Ice cores contain a record of how the ice sheets formed and moved, and how climate changed in the past. The lack of pollution in the atmosphere at the bottom of the world is superb for astronomy. Fossil finds help paleontologists chart the biogeography of the Southern Hemisphere, and support the theory of continental drift. Biologists are finding organisms that illuminate the history of life. Antarctica’s unique conditions make these explorations possible.