Antarctica is the world’s largest desert under the geographic definition based on very low precipitation. Although it is covered by ice, most of the continent receives little annual snowfall, making it drier overall than the Sahara.
A desert is defined by aridity, not by heat or sand. Antarctica’s interior is an extremely cold polar desert, while coastal areas generally receive more precipitation and support more wildlife. The Antarctic Ice Sheet stores roughly 90% of the world’s fresh surface water as ice.
The Sahara is the largest hot desert, but it is not the largest desert of every type. Antarctica covers about 14 million square kilometres, making it larger than Europe and nearly twice the size of Australia. Its ice sheet also reaches an average thickness of about 2 kilometres, which explains why satellite maps show a frozen continent rather than bare desert terrain.