Beneath the Saharan sands, a river valley
Evgeni ZotovIf someone traveling the Sahara Desert with you said, “I bet there used to be a huge river right about… here,” you would probably think it's time to stop for food and water. But that’s exactly what some scientists have said, and it turns out they were right. Obviously, that implies the arid Sahara hasn’t always been quite so arid. We don’t...