Today, the Sahara desert is known as one of the largest, hottest, and driest landscapes in the world. But over the past 800,000 years, the desert periodically turned green with vegetation. Now, scientists think they
Our planet has changed a lot over billions of years, from the location of the continents to the makeup of the atmosphere, and a new study looks in detail at the history of the Sahara desert – which wasn't always an arid wilderness.