The Atacama Desert in northern Chile, the driest non-polar desert on planet Earth, resembles a Martian landscape located between the Andes and the Pacific coast of South America.
Right between Chile and Peru lies the Atacama Desert. While it’s not exactly what you’d call tiny (it’s over 41,000 square kilometers in area), it often plays second fiddle to the Mojave and Sahara in the public imagination. But the Atacama is more interesting than both, as it alone is the driest desert in the world – and almost the driest place on Earth.
Welcome to the Atacama Desert, almost the driest place on earth
The exception is the dry valleys of Antarctica. This polar region has not seen precipitation for nearly two million years; Whipping katabatic winds push moisture-laden clouds away from the basin, making it the driest place on Earth.
But the Atacama Desert is right behind it, and it is believed to be drier than any other non-polar desert on the planet. The entire area receives an average of less than 0.6 inches of precipitation each year, and many places receive less as a result.
Some years there is no rain at all. The region is subject to long periods of drought, and climatologists suspect that the desert received no rainfall between 1570 and 1971 – a period of more than 400 years.
Then there are the parts of the Atacama that, according to weather stations, have never received rain. Already.
Why is the Atacama Desert so dry?
Oddly enough, part of the answer lies in its location on the Pacific Ocean. The Humboldt Current from the Pacific pulls the coldest water from the ocean floor to the surface, and the wind carries cool air inland.
The result is what meteorologists call a thermal inversion: warm, moist air is higher up, while cold, dry air is closer to land, producing a mild but very dry climate.
That’s another unusual choice about the Atacama: it’s not hot. Summer days typically hover around 65 degrees Fahrenheit and nights can drop as low as 32 degrees Fahrenheit.
Then there’s the fact that the Atacama has traded the desert’s iconic sand dunes for snow-capped peaks over 20,000 feet high. As the desert lies in the rain shadow of two large mountain ranges, much of the rest of the region lacks rainfall.
These relationships have lasted for ages; some scientists have estimated that the earth has been a desert for over three million years. This would mean that the Atacama is not only one of the driest places on earth, it is also the oldest desert on the planet.
Can anything survive in the driest desert in the world?
In such a climate, it is not surprising that many believe that the desert is completely devoid of life. However, this is only partially true.
Indeed, there are some areas of the desert that are too dry even for bacterial life—as evidenced by the fact that NASA used the Atacama as a test site for the devices that rovers use to search for life on Mars.
If a device is sensitive enough to find life even in the driest areas of the Atacama, then it can find life anywhere – if there is life to be found.
And NASA isn’t the only group to note the desert’s resemblance to the Red Planet. For years, the Atacama has been a popular choice as a filming location for Martian scenes in movies and TV shows.
However, other parts of the desert are anything but lifeless.
Hardy plants like lichens, salt grass and cacti can survive even in one of the driest places on earth thanks to an amazing trick. Unable to rely on ineffective rain to feed them, they draw their water from the camanchaca, the sea fog that rolls off the Pacific Ocean.
Some insects can settle in the Atacama, including grasshoppers and beetles, and where there are insects, their predators follow: birds, a small number of lizards and even fewer frogs.
Humboldt penguins nest in the cliffs where the desert meets the sea, swim in nearby cold streams, and brilliant flamingos venture into the salt flats when there is seaweed to eat.
But if you want to see some color in the Atacama desert, there’s nothing better than Desert Bloom. During El Niño years, when ocean currents bring warmer water and warm, humid winds to the arid regions, rare autumn rains can support field after field of beautiful wildflowers. Wealthy tourists in the area to witness the special event.
Stargazers are also frequent visitors, as the consistently cloudless skies and lack of light pollution make this one of the best places in the world to observe the night sky.
It makes the nearly one million people who live on the dry edges of the Atacama seem a little less crazy to have chosen the Atacama as their home. The land may not be welcoming, but it is filled with rare and spectacular beauty.
Enjoy this look at the Atacama Desert, one of the driest places on earth? Discover more desert wonders and learn about Desert Breath, the incredible art installation in the middle of the Sahara. Then discover Kolmanskop, the city swallowed by a desert.