The Sahara Desert was once filled with rivers, giant lakes and hippos. Scientists explain why it turns green every 20,000 years | World News
For most people, the Sahara is the ultimate symbol of endless sand, scorching heat and one of the harshest environments on Earth. Yet geology tells a remarkably different story. Beneath the dunes lie the remnants of ancient rivers, vast lakes and ecosystems that once supported hippos, crocodiles and thriving human communities. Scientists now know these…
