The desert covering much of northern Chile and ranking among Earth’s driest non-polar deserts is the Atacama Desert. It occupies a long strip between the Pacific Ocean and the Andes, extending through northern Chile and into parts of southern Peru, Bolivia and Argentina depending on the definition used.
Its extraordinary dryness comes from several geographic effects working together. The cold Humboldt Current cools air over the Pacific, while the Andes block moist air arriving from the east. The Chilean Coast Range also helps create a second rain shadow, leaving the central desert extraordinarily dry. Some weather stations have recorded no measurable rain for years, although coastal fog called camanchaca can still provide moisture.
The Atacama is not simply a landscape of empty sand. It includes salt flats, rocky plateaus, volcanic peaks and mineral-rich valleys. Copper and lithium mining are economically important, while the exceptionally clear, dry atmosphere supports major astronomical observatories. Scientists also use parts of the desert as Mars analogues because its soils and aridity resemble conditions on the Red Planet.