
Mars parallels: A rare rain event occurred in Chile's Atacama Desert in 2017. NASA's ARADS (Atacama Rover Astrobiology Drilling Studies) team studied microorganisms in 2018 that may have thrived in soils wet by the rain. They also tested a rover design that could eventually be used to search for microbial life in other extreme environments -- like Mars.

Field tests: Engineer Dean Bergman works on NASA's ARADS rover during field tests in 2018. The rover can navigate and drive independently, even over steep or uneven ground.

Dry and desolate: With very few microorganisms to be found in the soil, the Atacama Desert gave NASA scientists and engineers a realistic situation in which to practice searching for signs of life on Mars.

Drilling for samples: Members of the 2016 ARADS field science team look down into a more than seven-foot-deep pit from which they acquired samples.

Desert zone: Yungay in the Atacama Desert is among the most arid spots on the planet and one of the most similar areas to Mars. Here, Chilean biologists search for rock samples in 2017.

Signs of life: Not every corner of the desert is devoid of life. Here, a flamingo wades in a lagoon at Los Flamencos National Reserve.

Otherworldly terrain: Valle de la Luna in Los Flamencos National Reserve features otherworldly landscapes and spectacular skies.