Mention the word desert and the image that generally comes to mind is sand dunes, hot sun and maybe camels. You'd be right in thinking that, but there's lots of room for expansion in the definition of "desert." A desert is a place that receives very little precipitation — the official definition is "a landscape that receives less than 10 inches of precipitation in a year." Antarctica averages 8 inches along the coast and less as you move inland. For the most part, the weather on our planet's southern cap is exceptionally cold and brutally windy. Since it never is warm enough to melt, even small accumulations of snow add up over the centuries.