The Gobi Desert of Central Asia is one of the earth's desolate places. Its million square kilometers of sand dunes, sculpted badlands and saw-toothed mountains are alternately scorched by summer's high-latitude sun and frozen by winter's Siberian winds. It is not a place to explore unprepared: crossing vast, uninhabited areas between a sprinkling of oases requires careful planning akin to the siege tactics for scaling a Himalayan peak or traversing the Antarctic continent. There are few maps, and satellite navigation is of limited help to a traveler trying to choose among deeply rutted, wildly crisscrossing roads that wander as unpredictably as the nomadic settlements they connect. Even a modern expedition runs the risk of water, fuel and food shortages. Getting lost is not merely frustrating but a matter of serious danger.