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Image courtesy of the European Southern Observatory, photograph by C. Madsen.
Life in the Atacama Desert
Chile's Atacama Desert is one of the driest places on Earth. Few people live there, and most animals, plants, and even microbes find it difficult to scratch out a living in such an arid environment. There are a few hardy creatures that manage to survive there, and some of the unique aspects of this desert have drawn people into the region.
The Atacama is such an extreme environment that almost nothing lives there. In a few places fog from the ocean brings enough moisture for some algae, lichens, and cacti to survive. Some extremophile microbes actually live beneath or even inside of rocks to get out of the heat and preserve precious water!
Silver was mined in the Atacama in the 16th-18th centuries. Today, employment opportunities in large open-pit copper mines continue to lure people to the region. Sodium nitrate, a chemical used to manufacture explosives and fertilizer, was also mined here extensively in the past... until its value dropped in the 1940s when an industrial process was devised to make synthetic nitrate. Bolivia, Peru, and Chile even fought a war (the War of the Pacific) in the late 1800s over the valuable nitrate deposits! Port cities sprung up along the Pacific Ocean to ship out these various mining products.
The Atacama's human inhabitants employ ingenious techniques to capture water in this ultra-dry environment. In the village of Chungungo in northern Chile, residents use nets to "harvest" water from thick fog banks that roll in off the nearby Pacific Ocean!
The Atacama Desert has interesting ties to astronomy and space exploration that lure scientists to this unique environment. Because of the minimal light pollution in this sparsely populated region, as well as the almost total lack of cloud cover, the Atacama is a great place for astronomy. The European Southern Observatory operates two major observatories in the Atacama: La Silla Observatory and Paranal Observatory, which includes the Very Large Telescope. The harsh environment of the Atacama is like the planet Mars in several ways, so scientists have used it to test robots and sensors bound for the Red Planet. Since the Atacama is so nearly lifeless, testing equipment meant to detect life on other worlds in this nearly-sterile desert is a great way to check the sensitivity of those instruments. Finally, numerous meteorites have been discovered here. Minimal erosion due to lack of rainfall means that meteorites can be preserved for very long times after they plunge to Earth in the Atacama.