A desert is defined as a place that has little or no vegetation and receives less than 10 inches of precipitation a year.
By that definition, the world’s largest desert is most of Antarctica, about 5 million square miles (13 million sq km).
About 98% of Antarctica is covered by ice, and it is the coldest, driest, and windiest continent, with the highest average elevation.
Only cold-adapted plants and animals survive in Antarctica, including penguins, seals, nematodes, mites, tardigrades, algae and other microorganisms, and tundra vegetation.
The second largest desert in the world is the Sahara Desert in northern Africa, which covers 3.5 million square miles (9 million sq km).
The Sahara is 23 times larger than the Mojave Desert in California.
Most of the Sahara consists of rocky hamada, large sand dunes form only a minor part.