Slide 1 of 15
Mars on EarthBefore NASA's Curiosity rover was en route to Mars to answer questions about the planet's potential to host microbes now or in its past, the robot first had to cut its teeth in California's Death Valley. One of the hottest places on Earth is also one of scientists' favorite terrestrial stand-ins for Mars, due to its arid climate and unique geology.
Death Valley is one of several places around the world that serve as Mars stunt doubles as NASA scientists test the gadgets that will probe the Red Planet. Some of these places are hot, some are cold. Some are arid, some are covered in ice. All of them are among the harshest places on Earth, which is why scientists continue to trek to these spots to test their high-tech toys before shooting them into space.
Atacama Desert, ChileSlide 2 of 15
Atacama Desert, ChileOne of the driest places on Earth, the Atacama Desert is a 600-mile-long (966 kilometers) plateau in South America. The desert is so dry that it's nearly sterile about as Mars-like a place as Earth has to offer.
In 2004, NASA-funded scientists spent four weeks in the Atacama, studying the dearth of life there for clues about how life could survive on Mars. The arid region became a proving ground for robots looking to fine-tune their life-form detection skills that could help in the search for life on Mars.
The desert stays dry because of a so-called rain shadow a dry area on the leeward side of the Chilean Coast Range, combined with a cold offshore current that helps cap any moisture from breaking through.
Some weather stations in the area have never received rain, so in 2011 the region made global headlines when 31.5 inches (80 centimeters) of snow fell in the Atacama, which was its heaviest snowfall in two decades.Slide 3 of 15
Lake Vostok, AntarcticaSlide 4 of 15
Lake Vostok, AntarcticaWhen a team of Russian scientists drilled into the previously untouched waters of Lake Vostok, buried under more than 2 miles (3 km) of Antarctic ice, in 2012, the science world watched closely in hopes that the expedition would offer clues about how life could have survived on frigid Mars, where the average temperature is about minus 80 degrees Fahrenheit (minus 60 degrees Celsius).
When an ice sheet covered the lake around 34 million to 14 million years ago, the lake was sealed from the outside world. Scientists suspect that the massive freshwater lake could be home to cold-loving creatures that have been living in darkness under the ice for millions of years. That's similar to what might be expected on Mars.Slide 5 of 15
Pico de Orizaba, MexicoSlide 6 of 15
Pico de Orizaba, MexicoSay humans make it to Mars, and decide to colonize the Red Planet. How will we make it habitable? That's what researchers in Mexico have been working on for years.
At the treeline on the Pico de Orizaba volcano in Mexico one of the world's highest treelines scientists are studying how life first crept up these cold slopes. What they find could help turn Mars into a habitable planet.
The Pico de Orizaba Volcano, which last erupted in 1846, stands at 18,619 feet (5,675 meters). The treeline extends to about 13,100 feet (4,000 m), one of the highest elevations on Earth capable of supporting life.
Pines on Mars might sound far-fetched, but for years scientists have been hiking up and down the mountain in search of clues about how life could be jump-started in a harsh climate such as on Mars. What they find here at the extreme edge of life could get the ball rolling on Mars in a few generations.Slide 7 of 15
Ellesmere Island, CanadaSlide 8 of 15