The Sahara Desert covers the majority of Northern Africa. It is the third largest desert in the world and also the hottest. The borders of the Sahara Desert include the Red Sea on the east, the valley of the Niger River and the Sudan on the south, the Mediterranean and the Atlas Mountains on the north, and the Atlantic Ocean on the west. The desert has gone through shifts in temperature and moisture over the past few hundred thousand years. Although the Sahara Desert is very dry today, it is expected that it will become green again in about 15000 years. also read: What is a Tardigrade? It's not even the biggest desert. Despite what you may have learned in school, the Sahara desert is not actually the world's largest desert. The Sahara Desert is the third largest in the world. The first two are Antarctica and the Arctic. The Sahara desert now comprises eight percent of the world's land area -- one could actually place the entire continental United States within the Sahara Desert and still have a few thousand square miles of desert left over. The Sahara Desert covers 3.6 million square miles. It is almost the same size as the United States or China. The Sahara is bordered by the Atlantic Ocean on the western edge, the Atlas Mountains and the Mediterranean Sea to the north, the Red Sea on the east, and the Sudan and the valley of the Niger Riveron the south. There is sparse grassland in some parts of the desert including the highlands and northern and southern parts of the desert. A 30-mile giant eye in the Sahara once served as a geographical landmark for astronauts. Dust from the Sahara has produced a massive carbon sink in the Bahamas, and humans could mimic nature by artificially repeating the process elsewhere. More than 30,000 petroglyphs of animals native to rivers have been found in southeast Algeria in the Sahara. The Sahara Desert is made up of sand dunes, sand seas, gravel plains, stone plateaus, dry valleys, salt flats, mountains, rivers, streams, and oases. Eleven countries have parts of the Sahara Desert within their borders. They are: Libya, Algeria, Egypt, Tunisia, Chad, Morocco, Eritrea, Niger, Mauritania, Mali, and the Sudan. A substance called “Libyan Desert Glass” is found in the Eastern Sahara and the deserts of Libya, this glass is of unknown origin and has been found in ancient Egyptian Jewelry such as Tutankhamun’s Pectoral There is an art installation in the Sahara which covers over 100,000 square meters and can be seen from the sky. It has snowed on three occasions in the Sahara in the last 40 years: in 1979, 2016, and in January 2018. In all these cases, the snow melted quickly, and the desert reverted to its sandy landscape. The Sahara Resurrection Plant can survive over 100 years without water. It completely dries up and rolls around the desert until it finds the wet ground and then only buds if it happens to rain shortly after that. also read: Amazing Facts: Some Random Facts everyone should Know