There’s a Long-Lost ‘Paleo-River’ Beneath the Sahara Desert Nobody Knew Existed

Stretching across 9,400,000 square kilometers of northern Africa-a land area comparable to the entire United States-the Sahara is the largest hot desert in the world, an expanse of shifting sands where only the hardiest wildlife can eke out a living. But new satellite imagery of the Sahara has revealed that the desert wasn’t always such a bone-dry dead zone.