When you think of a desert you probably think of sand, camels and searing hot sun. However a desert is defined by having lower than 25 centimetres of precipitation (either through rainfall or snow/ice) per year, there are many deserts in the world that are polar deserts, places that are so cold that they receive very little rainfall each year. The largest of these is the continent of Antarctica.
Antarctica receives on average 50 mm of precipitation per year, mainly in the form of snow and spans the near 14,000,000 kilometres of the continent, nearly as large as the USA. In comparison the second largest desert in the world, The Sahara Desert in northern Africa is 9,400,000 km. The Sahara is the more commonly known desert as it fits the stereotypical characteristics that we would think of when considering a desert, but is nowhere near as large as Antarctica.