Large verdant disks of earth stretch across the horizon at the edge of the expanse of desert known as the Empty Quarter. Farmers employ center-pivot irrigation to cultivate crop circles measuring one kilometer in diameter. The wells irrigating these circles range from 100 to 200 meters in depth and extract “fossil water” that rained onto the earth thousands of years ago. The fields must be irrigated year-round to sustain a four-month crop. Nourished with fertilizers and water, the once-barren land comes to life, but its time is limited. Technology and persistence can master this arid terrain, but not permanently. After some twenty years, the wells will be diminished and the fields abandoned, to be reclaimed by the desert sands. Saudi Arabia.