What it’s like to visit Mars on Earth

CNN  — 

Ethereal images from the Mars rover Perseverance have lit up the internet ever since NASA’s latest high-tech robot landed on the Red Planet on February 18.

The photos, released on NASA’s website, depict a desiccated landscape of lifeless orange-brown soil with rugged, rocky hills snaking across the horizon.

Though decidedly otherworldly, there’s also something strikingly familiar about them. Perhaps that’s because the images look a lot like a place back here on Earth – a remote desert in Chile that NASA itself has dedicated time and money to exploring.

“You can argue whether the Dry Valleys in Antarctica or the north-central part of the Atacama is the driest place on Earth, but some parts of the Atacama only get rainfall every 20 to even 100 years,” says Brian Glass, principal investigator of the Atacama Rover Astrobiology Drilling Studies (ARADS; 2016-2019), which used the Atacama Desert to field0test tools and techniques for future missions to Mars.

Because the Atacama is such a dead and desolate place, NASA has come to view it as the perfect analogue to Mars on Earth, testing rovers here regularly since 1997. The latest have used prototype instruments to try and detect life, “because if we can’t do it in one of the deadest places on Earth, we have no business taking it to Mars,” explains Glass.

NASA's ARADS team works with its prototype Mars rover in Chile's Atacama Desert in 2018.

The Atacama is a thin 1,000-mile strip of desert in the northern half of Chile between the Pacific Ocean, to the west, and the Andes, to the east. Glass says that to understand just how lifeless certain parts of it are, you can think of it in terms of organic signal (i.e. life) to background noise.

“The signal – even in the Mojave and remote parts of the US mainland – is still pretty loud,” he says. “You still see shrubs, cacti, microorganisms, scorpions, insects; there is still an ecosystem.”

On the contrary, in the hyperarid Atacama, “you could literally fall down, cut your arm on a rock and you wouldn’t worry about getting an infection because there are no local pathogens,” he said.

What’s it like to visit a place that NASA likens to Mars on Earth? Like Mars, the Atacama has an extreme topography with vast salt flats and soaring volcanoes, including the highest active one on earth. It’s also got some of our planet’s darkest skies and largest astronomy facilities.

With Chile vaccinating its population faster than anywhere else in the Americas (including the United States), the otherworldly Atacama will likely be one of the first places in the region to welcome back international visitors. So, if those dramatic images from Perseverance have piqued new interest in Mars, the next best thing may only be an earthly flight away.

NASA has come to view parts of the desolate Atacama Desert as the perfect analogue to Mars on Earth.

The driest place on earth?

When scientists call the Atacama the driest non-polar spot on earth, it’s places like Yungay that they’re talking about. This remote backland, about 55 miles from the city of Antofagasta, is where NASA conducts much of its research.

“Yungay is in a long valley with windy eroded hills to either side,” Glass says. “It’s very brown and very barren; there is no signs of anything alive.”

There is, ironically, a 36-foot-tall sculpture of a hand clawing its way out of the desert nearby. Known as Mano del Desierto, it was placed close to Yungay in 1992 by Chilean artist Mario Irarrázabal – long before any talk of this area as a place where NASA would one day search for signs of life hidden beneath the surface.

Though Yungay was long thought of as the driest place in the Atacama, recent research indicates that title might actually belong to Maria Elena South, which lies near a nitrate mining town about 170 miles further north.

Neither location has any facilities or tourist attractions, but they’re key spots for appreciating the emptiness of the Atacama and its parallels to Mars – particularly since the McMurdo Dry Valleys of Antarctica (which many scientists believe are even drier) are exceptionally hard to reach.

El Tatio is kind of a mini-Yellowstone with 80 gurgling geysers.

Volcanoes and geysers

Mars is home to the tallest volcano in our solar system, Olympus Mons, while the Atacama houses the highest active volcano on earth, Ojos del Salado.

This muscular grey-brown mountain rises 22,615 feet above sea level and is the second highest peak in the Western Hemisphere after Aconcagua in Argentina.

Yet, the superlatives don’t stop there; its permanent crater lake is believed to be the highest body of water anywhere in the world.

“The look of this impressive volcano in an area surrounded by other high volcanoes all over 6,000 meters (nearly 20,000 feet) makes you feel like you are very small,” says Ercio Mettifogo, who runs the local adventure tour operator Puna de Atacama.

Ojos del Salado is not a highly technical climb, though the extreme altitude, punishing winds (up to 74 mph) and sub-zero temperatures (below -20 degrees Fahrenheit) certainly make it a challenge. Most summit between November and April on expeditions of between 8 days for experts and 12 days for hobby mountaineers.

The Atacama Altiplano is often likened to the Tibetan Plateau, and the region near Ojos del Salado is home to some 17 mountains above 6,000 meters, Mettifogo says, making it a hub for adventure travel.

Further north, near the tourist town of San Pedro de Atacama, lies yet another geothermal wonder of the Atacama: El Tatio, a mini-Yellowstone with 80 gurgling geysers and even more gassy fumaroles.

Backed by a panorama of snow-capped volcanoes, El Tatio is the largest geyser field in the Southern Hemisphere and the highest on Earth at 14,170 feet above sea level.

Nevado Tres Cruces National Park is home to flamingos.

Salt flats and flamingos

Much of the Atacama may be as dead as Mars, but the desert bursts with color around its spectacular salt flats, known as salares, whose briny waters support a wide array of life, including flamingos.

There’s the rare Andean flamingo, which has yellow legs and black-tipped wings, and the slightly smaller James’s flamingo, which has brick-red legs and a bright yellow beak. There’s also the pinkest flamingo of them all: the Chilean flamingo, which, despite its name, is the most common across South America, found from Argentina up to Ecuador.

These fluffy pink birds are most easily spotted in high Andean parks like Los Flamencos National Reserve, near San Pedro, and Nevado Tres Cruces National Park, near the city of Copiapó.

“The salt flats are also famous for their multicolored lagoons,” says Gabriel Rojas of Turismo Atacamensis, who takes visitors up to swim in the ethereal turquoise lagoon of the Salar de Pedernales, just north of Nevado Tres Cruces National Park. Pedernales also has blood red, navy blue and emerald green pools, all linked on a 2-mile hiking trail Rojas built with his brother.

Some scientists believe that, if we are to find signs of life on Mars, it will be in its historic salt ponds, which formed in places like the Gale Crater and are said to be remarkably similar to those found on the Altiplano of South America.

The ethereal turquoise lagoon of the Salar de Pedernales is just north of Nevado Tres Cruces National Park.

The clearest skies in the world

The Atacama Desert is not only a NASA test site for future missions to Mars; it’s also the very place from which some of the most advanced planetary observations are made here on Earth.

Northern Chile is home to some 70% of the global infrastructure for ground-based astronomy. The biggest projects of the 2020s – including the Giant Magellan Telescope and the Extremely Large Telescope – will all rise atop barren hills here in the coming years.

“When night comes, the silence and darkness produced by the absence of large cities – and their noise and light pollution – becomes like a stairway to heaven that makes you feel almost like you can touch the cosmos with your hands,” says Cristóbal Vergara, founder of Turismo Tembeta, which runs stargazing tours from the city of La Serena.

The Elqui Valley, on the southern edge of the Atacama Desert, has become a major hub not only for scientists, but also amateur stargazers.

“The coastal mountain range retains most of the mist coming in from the Pacific, allowing for little cloud cover and near constant clear skies here,” Vergara says of the conditions, noting that you can just lay back on the quartz-filled soil with a blanket once the sun sets.

For something more professional, there are nearly a dozen observatories near the tourist hub of Vicuña open to everyday astro-tourists hoping for a close-up view of the Jackson Pollock sky. Several of the research-based facilities – including Gemini South, Cerro Tololo, La Silla and Las Campanas – open up on weekends for guided visits, too.

The Elqui Valley was named the world’s first International Dark Sky Sanctuary in 2015. That designation led to a boom in lodgings with see-through roofs so you can comfortably sleep under a meadow of stars.

Vergara says the best part of stargazing here is that you’re “in the very place where grand explorations, advances in technology and new astronomic discoveries that may help the future of humanity are occurring every day.”

The Atacama might not be as cold or harsh or alien as Mars, but it’s the closest we’ve got to the Red Planet on Earth. To visit is to experience the mind-bending sensation of what it might be like to travel out of this world.

Mark Johanson is a freelance journalist based in Santiago, Chile. His writing has appeared in Lonely Planet, Men’s Journal, GQ, Newsweek and The Guardian, among others. You can follow him on all social channels @MarkontheMap.