A Mars Here on Earth
By Jenna Cammerino
One might not expect to find a glimpse of Mars here on Earth, but in the burnt orange peaks and plateaus of the Atacama Desert, located in Chile, we may catch an up close look of what life could be like on our celestial neighbor. Boasting various terrains, from salt flats to dry valleys and snowy volcanoes, the desert is home to much of the same diverse topography and extreme conditions found on Mars.
The Atacama, considered to be one of the oldest deserts in the world, is known to host an incredibly hostile environment. Pinched between the Andes mountains and the Pacific in the northern part of Chile, it boasts one of the driest climates on the planet. Along with the Andes lining the eastern side of the area, the desert sits beside The Coastal Range, a mountain range on its west, that runs about 3000 km along the coast of the Pacific Ocean. While these mountains border the entirety of Chile, they reach their highest heights, an altitude of around 3114 kilometers, running through the Atacama.
In fact, it is these very mountains that have helped birth the arid wasteland. Both of these ranges cast what is called a “rain shadow” upon the valley of the desert. The warm and moist air that comes in from the ocean and wind currents will rise as they move along the mountainside. When this air reaches the top, it cools and condenses there. Because of this, very little precipitation is able to advance beyond the mountains. Instead, the dry air is pushed into the desert and the basin of this region can go over 20 years without rainfall.
The incredibly arid climate formed in the middle valley of the desert is referred to as its hyperarid core. The core has been dubbed one of the driest places on earth, a title most notably reserved for its inhabiting towns such as Yungay, Chile. The soil here is highly oxidized, much like that on Mars, and is found to be nearly barren.
The dry climate and lack of organics in the soil present an optimal model for the Red Planet. For this reason, it has become a site of intrigue for various researchers looking to develop methods of detecting, as well as understanding, life on Mars.
Albeit for the creation of an inhospitable wilderness, the moisture brought in from the ocean has allowed for certain parts of the desert to flourish with life. In fact, the dry soil directly to the east of the Coastal Range has been found to house various microorganisms, some of which have been shown to be highly tolerant of the UV levels as well as other inimical conditions of the desert. Study of these microbes may provide some exciting insight on what our Martian neighbors may look like.
While the hyperarid core is much more infertile, it has still been found to contain bacteria, particularly in incredibly saline conditions, living inside of halite rocks. However, this region is mostly used to learn how these extreme, Mars-like conditions may impact various microorganisms on Earth and Yungay has, hence, become a hot spot for research. By analyzing biosignatures and microbial communities found in these soils, scientists can determine what kind of life may develop and even thrive in these conditions.
In addition to its incredible lack of moisture, the desert experiences some of the highest exposure to UV radiation on Earth. The coastal side of the desert can receive anywhere between 13 to 18 megajoules per square meter a year, while the mountainside can receive doses as high as 576 megajoules per square meter annually. For certain types of radiation, these annual peak levels in the Atacama can be 60% higher than that in northern Africa, which consists of the Sahara Desert.
But this desert is home to much more than dry soil and flatlands. With turquoise salt lagoons like Salar de Pedernales and the highest volcano in the world, Ojos del Salado, the Atacama is filled with beautiful scenes that can mirror Mars in more ways than can be seen through a microscope.
Planetary analogs like the Atacama desert help to bring us closer to exploring the wide range of environments not only in our solar system, but all across the universe. So until we take our first steps on Mars, we may get a sneak peak by traversing the various worlds found right here on Earth.
Leadbeater, C. (2017). Exploring Chile’s Atacama Desert. National Geographic.
Jenna Cammerino is a graduate student at Syracuse University. She has a B.S. in math and physics and is currently pursuing an M.A. in television, radio, and film. She is passionate about astrobiology and, as a YSP Research Associate, she hopes to use various outlets to share that science in an exciting and accessible way.