Did you know the Sahara Desert was once a lush, green landscape? In Northern Chad’s Ennedi Massif, archaeologist Mahamat Ahmat Oumar is leading a groundbreaking mission to preserve prehistoric rock ...

A cloud of dust escapes from an excavation site in the sand of Chad's arid north, where scientists are looking for signs of human habitation in an area once humid and called the "Green Sahara." ...