12 Facts About Deserts and Extreme Environments

The Driest Places on Earth

1. The Atacama Desert in Chile is the driest non-polar desert on Earth. Some weather stations in the Atacama have never recorded rainfall in their entire operational history. Parts of this desert are so dry that NASA uses them as analogs for Mars, testing rovers and life-detection instruments there.

2. Despite its extreme dryness, the Atacama Desert supports microbial life that survives on atmospheric moisture alone. These extremophile bacteria extract water directly from the air using specialized salt crystals — a discovery that expanded scientists' understanding of where life can exist, including on other planets.

3. Antarctica is technically the largest desert on Earth, covering 14.2 million square kilometers. Despite being covered in ice, it receives less than 50 millimeters of precipitation annually in its interior, qualifying it as a polar desert. The Dry Valleys of Antarctica haven't seen rain or snow in nearly 2 million years.

Extreme Heat and Temperature Swings

4. Death Valley, California, holds the record for the highest reliably recorded air temperature on Earth: 56.7 degrees Celsius, measured at Furnace Creek on July 10, 1913. Ground temperatures in Death Valley have been measured at over 93 degrees Celsius — hot enough to fry an egg.

5. The Sahara Desert can experience temperature swings of over 37 degrees Celsius in a single day. Daytime temperatures can soar above 50 degrees Celsius, while nighttime temperatures can drop below freezing. This extreme fluctuation occurs because dry air and clear skies allow heat to rapidly escape at night.

6. The Sahara wasn't always a desert. Between 10,000 and 5,000 years ago, during the African Humid Period, the Sahara was a lush grassland with lakes, rivers, and abundant wildlife. Rock art in the Sahara depicts giraffes, elephants, and even swimming humans — evidence of its green past.

Life in Extreme Conditions

7. Tardigrades, also known as water bears, are the most resilient creatures known to science. These microscopic animals can survive temperatures from -272 degrees Celsius to 150 degrees Celsius, pressures six times greater than the deepest ocean trenches, radiation doses hundreds of times lethal to humans, and even the vacuum of space.

8. The Saharan silver ant has evolved to withstand body temperatures up to 53 degrees Celsius, making it one of the most heat-tolerant terrestrial animals. It survives by foraging during the hottest part of the day — when its predators are hiding from the heat — and its silver hairs reflect sunlight like microscopic mirrors.

9. The camel's hump does not store water, as commonly believed. Instead, it stores up to 36 kilograms of fat, which can be metabolized into both energy and water. A thirsty camel can drink up to 135 liters of water in just 13 minutes, and their oval-shaped red blood cells allow blood to keep flowing even when they're severely dehydrated.

Desert Mysteries and Phenomena

10. The Skeleton Coast of Namibia is one of the most inhospitable places on Earth, where the Namib Desert meets the Atlantic Ocean. Shipwrecks litter its shores, some now kilometers inland as the desert has reclaimed the coast. The Namib Desert itself is estimated to be at least 55 million years old, making it the world's oldest desert.

11. The Sahara Desert expands and contracts in a 20,000-year cycle driven by changes in Earth's orbital tilt. The next greening of the Sahara — when the desert will once again transform into grassland — is predicted to occur in approximately 15,000 years, driven by the same Milankovitch cycles that cause ice ages.

12. Underneath the Sahara lies one of the world's largest fossil water aquifers, the Nubian Sandstone Aquifer System, containing an estimated 150,000 cubic kilometers of groundwater. This ancient water, trapped underground for up to a million years, has been dated using isotopes and represents a non-renewable resource that accumulated during previous wet periods.