The vastness of the Sahara is unimaginable; Spanning about 9 million square kilometers, it is the world's largest desert outside the polar regions. So, as you'd expect, there's a lot of fun going on inside of it. For this answer, I selected only the most interesting pieces of news that I could find in this area. Despite its (deserved) reputation as a scorching hot wasteland, it still occasionally snows in the Sahara. Three significant instances of snowfall were recorded here, all in Algeria, and in all cases the snow melted within a few hours of falling.
The last time it happened was in January 2018. In some parts of the Sahara, especially Tunisia, desert roses form. These are beautiful gypsum crystals, encrusted in sand, created by the evaporation of shallow waters. It's easy to see how they got their name. In Mauritania, you can find a giant circular rock formation known as the Richat Structure, or the Eye of the Sahara. It is forty kilometers in diameter and was originally thought to be an impact crater, but is now understood to be an eroded dome of volcanic rock. About 14,500 years ago, an era known as the African Wet Age began, which lasted until ~6,000 years ago.
During this time, the monsoon in West Africa became stronger and the Sahara region experienced a marked increase in rainfall. The desert has given way to lush savannah, leading to a green Sahara. Lake Chad is currently the largest body of water in the Sahara, but it is only a shadow of its former lake. While the area is verdant, Lake Chad is Lake MegaChad, more than 700 times its modern size! In fact, it is by far the largest lake in the world with an area of over one million square kilometers. The Sahara Desert contains more prehistoric rock art than anywhere else in the world. These ancient paintings date back 12,000 years and depict everything from war and agriculture to swimmers and now-extinct local wildlife.
They are an invaluable window into the lush, rainy past of this now bleak desert. In Eastern Morocco, there is an incredibly rich fossil site - the Ice Cream Bed - from about 95 million years ago. It shows that this part of the Sahara was once a marshland, home to some of the largest carnivorous dinosaurs of all time, 30-ton sauropods, giant crocodiles, sawfish larger than minivans, and more. Silver ants in the Sahara desert are well adapted to the extreme temperatures in a spectacular way. Their beautiful silver hair reflects sunlight and they have special proteins that allow them to withstand temperatures up to 53 degrees Celsius!
They can even only spend 10 minutes a day in the sun, so they have to be fast - in fact, for their size, they're the third fastest creature on Earth. (That paragraph is criminally brief to get an overview of these amazing ants, I'll have to deal with them fairly one day...) The Sahara is home to a fascinating plant species. The plant is called Anastatica hierochuntica, also known as Jericho rose. When the dry season begins, it shrinks and becomes completely dry, separating from the ground and blowing away in the wind. However, when exposed to moisture during the next rainy season, it "revives itself", regaining its former vitality.
In Chad you can find Guelta d'Archei, a beautiful secluded oasis in a deep sandstone gorge. It is used daily by local herders to quench the thirst of thousands of camels, which have blackened the waters with their droppings. The oasis is also the only surviving colony of West African crocodiles in the Sahara. In 1993, electrician Emile Leray was traveling in the desert of Morocco when his car allegedly hit a rock and its front axle was destroyed. He dismantles the wreck and uses the parts to build a fully functioning motorcycle, which he names his "Steel Camel" and rides on to civilization.
(It's worth mentioning that, while this is really interesting, it's unlikely to be as bold a survival story as is often claimed. What's more likely is that Leray came to the Sahara with clear intentions. obviously built a motorcycle by himself. Citroen there.) The hottest known part of the Sahara is Bou Bernous, a very small and isolated town in western Algeria. Its average temperature over the course of a day has been recorded at 47 degrees Celsius, the highest measurement anywhere on Earth! If you look at a satellite map of Libya, you may notice a sudden small black dot.
It's Waw an Namus, a verdant oasis inside a volcano, famous for its black tephra (basically volcanic gravel). There are many species of birds that live here, unlike the surrounding wasteland. The ancient Romans made a number of military expeditions deep into the Sahara, even venturing into sub-Saharan Africa. For example, a group of explorers went to Lake Chad, which they called "the hippo lake". They set up a small garrison here. In the Dogon region of Mali, at the southernmost tip of the Sahara, there is a steep cliff known as the Bandiagara Cliffs. Here, locals build spectacular mud hut villages that hug the slopes of sandstone cliffs.
The Mauritian Railway is the railway line with some of the longest trains in the world. These trains can be up to three kilometers long, and weigh tens of thousands of tons! They carry iron ore and occasionally carry passengers. In Tunisia, there is a unique desert village called Matmata. Here, some of the local Berbers live in underground houses, formed around one or more large pits, perfect for shielding themselves from the scorching Sahara sun. The town was the main filming location for Tatooine in the original Star Wars movie. One of Egypt's UNESCO World Heritage Sites is Wadi El Hitan, or the Valley of the Whale.
In fact, this is a paleontological excavation site where the distinctive fossils of the ancient whale Basilosaurus have been discovered. Remnants of sharks, manatees, turtles and even the first pelicans have also been found there, suggesting that the sandbar was once a shallow sea. Morocco boasts the title of having the largest concentrated solar power plant in the world, Ouarzazate Solar Power Station. Construction on it began in 2013 and when completed it will produce an estimated 582 megawatts of energy. The project cost about $2.5 billion. Although not nearly as famous for architecture as Egypt, Sudan is home to more than 350 pyramids - more than twice as many as the old country.
These structures were built by the Nubians, then known as the Kush Kingdom, beginning around 800 BC. When you think of the Sahara landscape, you might think of dune fields and dramatic rock plains, but Algeria's Hoggar Mountains are more than impressive. These plateaus are of volcanic origin, and some of their peaks are nearly 3 km high. In the Niger desert, you can find the tallest mud-brick building in the world, the Agadez Mosque. It was built in 1515 and has remained largely unchanged since. In Morocco every year, Marathon des Sables is held - arguably the toughest and most challenging race in the world.
At 251 kilometers long, the track is six times longer than a standard marathon and takes almost a week to complete. Due to COVID-19, the race has not been held since 2019. There is a 7,000 square kilometer lake in the Tunisian Sahara called Chott el Djerid which - in the summer - becomes the largest salt pan in the desert. Due to evaporation, a layer of salt accumulates on the surface of the water, thick enough to overturn a car. When winter comes, it returns to its succulent state. On average, 182 million tons of Saharan dust is blown westward across the Atlantic Ocean each year. Of which, 28.8 million tons are located in the Amazon Rainforest of South America.
This appears to play an important role in forest biodiversity, as dust carries minerals important for fertility such as phosphorus. Some of that dust also ends up in Cape Verde, an archipelago off the west coast of the Sahara, and concentrated in the Viana Desert. This small dune field can be considered an extension of the Sahara Desert in the Atlantic Ocean. Egypt is home to both the Black Desert and the White Desert. The area was formerly a volcanic area filled with basalt mounds, in which dinosaur remains have been unearthed. The latter is famous for its chalk rocks, which have been eroded into intricate shapes.
So I'll leave it for today. At first glance, the Sahara seemed pretty bare, but upon closer inspection, I realized that I couldn't put all of its interesting features into one easy-to-understand answer. I hope you like the ones I chose. Also, I know the phrase “Sahara Desert” is the word, because the word Sahara itself comes from the Arabic word for desert. However, I used the phrase in this answer, mostly to mix up the word choice a bit. It's a bit ironic that I ended up using a repeated name to avoid repetition, but anyway…
