This striking false color image shows a “shadowy” patch of giant wind-sculpted ridges and sand dunes in the heart of Iran’s Lut Desert — one of the most extreme environments on Earth. The Lut Desert covers more than 7,000 square miles (18,000 square kilometers) in southeast Iran.
It’s a salt desert, meaning its sand contains a mixture of salt and other minerals left over from an ancient lake, and it contains almost no water or vegetation. The desert’s Persian name, Dasht-e Lut, means “empty plain.” The region is often called the “hottest place on Earth,” but that’s open to interpretation. The highest air temperature on Earth in the past century — 130 degrees Fahrenheit (54.4 degrees Celsius) — was recorded in 2020 at Furnace Creek Ranch in Death Valley, California.
But, according to NASA, the Lut Desert’s ground surface temperature reached a maximum of 177.4 F (80.8 C) in 2018, a joint record shared with Mexico’s Sonoran Desert. The sand in the Lut Desert gets so hot, in part, because of the large, dark patches of ancient lava that cover the surface and lie just beneath the sand.
The satellite image above shows two geological features: a field of parallel ridges, known as yardangs, on the left; and a huge, shadowy patch of sand dunes on the right. The photo was taken using the solar reflective spectral range — a mix of ultraviolet, visible light and infrared — which has made these features appear deep purple. Viewed from above in only visible light, these features appear little different from their surroundings, as recent images from NASA’s Terra satellite show.
Yardangs are high ridges eroded from the desert bedrock by wind blown away over millennia. These ridges are particularly interesting because, according to UNESCO, they are some of the best examples of this feature anywhere in the world. They are about 25 miles (40 kilometers) long and rise about 500 feet (150 meters) above the surrounding area.
The Lut Desert also has some of the world’s tallest sand dunes, up to 1,500 feet (460 meters) high, according to NASA’s Earth Observatory. However, the dunes in the image are only up to 1,000 feet (300 meters) high.
The heat and dryness of the Lut Desert make it almost completely unsuitable for life or abiotic environments. However, according to the European Space Agency (ESA), there is a small, shallow body of water dozens of miles northeast of the dunes, which enables some species to survive in this harsh landscape.
But far from this water source, the Lut Desert likely contains some truly barren areas where even microorganisms cannot survive. “Some reports claim that research groups brought sterilized milk to the desert and left it open in the shade, but the milk remained sterile,” ESA representatives wrote. However, there is no record of this research online.
The region is prone to tectonic activity due to several fault lines that run beneath Iran and contribute to the region’s greatest volcanic activity. In 2003, a magnitude 6.6 earthquake shook the country, and its epicenter was about 100 miles (160 km) south of the dunes and yardangs in the image, according to the ESA.