As the largest desert in the world, it is hot and barren, but this is what makes it so 'mysterious' and desirable.

So, how big is the Sahara? And how deep is it? If we were to empty it of sand, what would be left underneath? Let's take a closer look at the Sahara Desert that has fascinated so many explorers.

The largest desert in the world is the Sahara Desert, located in the north of the African continent, with a total area of about 9.32 million square kilometers, the same size as our land mass.

The Sahara Desert has formed around 2.5 million years ago when the climate in the region became arid, making it difficult for life to survive and gradually forming a vast desert.

The Sahara Desert is approximately 4800 km long from east to west and between 1300 and 1900 km wide from north to south. The desert is dotted with untold amounts of sand, although this sand is not immobile in the desert.

The most convenient way for sand to leave the Sahara Desert is to "rise up in the wind", to be carried by the wind into the atmosphere, and then to be carried elsewhere.

From the point of view of the baroclinic wind belt, the main wind belt affecting the Sahara Desert region is the northeast trade wind belt, where the sand is carried by the trade wind into the atmosphere and moves from east to west. In satellite maps, we can see very clearly the widespread dust and sand, which from the point of view of natural disasters is a "dust storm".

But did you know? It was not born this way, and there is plenty of archaeological evidence to prove that it was once an oasis. There are still traces of dry riverbeds in the Sahara Desert today, and archaeologists have found fossils of dinosaurs and other plants and animals, as well as many precious artifacts from the Stone Age.

National Geographic has reported on the discovery by international archaeological teams of Stone Age burial sites in the Sahara Desert, 10,000 years old, which have unearthed a large number of precious fossils and have revealed the 'green Sahara' of the past. It is important to understand that although the Sahara is a large desert, this does not mean that every part of it is covered in yellow sand as one might expect.

In terms of desert type, the Sahara is a mosaic of desert, gravel, and rocky deserts, with small areas of salt desert in the center and earthy deserts in the north.

The Arabian Desert, the second largest desert in the world, is located on the eastern edge of the Sahara Desert in North Africa and is mostly gravelly desert and exposed rock dunes. On the edge of the Arabian Desert is the ancient city of Petra, once the capital of the Nabataean dynasty and a historic city in southern Jordan, hidden in the isthmus between the Dead Sea and the Gulf of Aqaba.

It is one of Jordan's mysterious ancient cities in the southern desert and one of the country's most prestigious monuments. Petra is located on a dry, high mountainous terrain and is almost entirely carved out of rock.