For decades, scientists have puzzled over why Earth stayed warm and alive while Mars turned cold and dry. Both planets began with similar ingredients—rocky surfaces, carbon, water, and sunlight—but ...

Snowfall in deserts is mainly the result of sharp temperature swings. Many deserts lie far from oceans or are located at high altitudes, both of which allow heat to escape quickly after sunset. In ...

Earth’s driest ecosystems are a study in extremes: They can be blazingly hot stretches of sand like the Sahara Desert or shatteringly cold expanses of ice such as those in Greenland and Antarctica.

The Sahara is the world's most famous desert, a land of rolling dunes through which camel caravans once roamed from Marrakech to Timbuktu and beyond. At roughly 3.3 million square miles, and occupying ...