The most difficult deserts of Africa riddles

The Richat Structure in Mauritania, also known as the Eye of the Sahara, was interpreted as an asteroid impact structure, but no evidence of shock metamorphism has been found. Today, scientists believe that it is a huge (40 km in diameter) and deeply eroded geologic dome.

The Berber language is ancient and has 2200 years of written tradition. In 2011 Berber became a constitutionally official language of Morocco, after years of persecution (under the policy of Arabization). There is a movement among speakers of the closely related varieties of Northern Berber to unite them under a standard language.

Most of the Sahara consists of rocky hamada; ergs (large areas covered with sand dunes) form only about 20% of the total area.

This is an astronaut photo of the Al Khufrah Oasis in Libya. The circular shape of fields is characteristic of center pivot irrigation. These fields are approximately 0.6 mile (1 kilometer) in diameter. Lighter colors indicate fields that have been harvested recently or just planted.