Ever wonder what it’s like on Mars? There are those great photos from the Mars rover, offering close-ups of red dirt and oddly shaped rocks. But that takes you only so far. NASA astrobiologist Chris McKay has been visiting some Marslike places on Earth to try to figure out what the Red Planet — and others — might be like, writes Steve Nadis in Discover magazine.

McKay “ventures to some of Earth’s most extreme environments to study the closest facsimiles he can find to Mars and other distant outposts, on a mission to learn how life might exist beyond our planet,” Nadis writes.

Here’s what McKay calls the “seven wonders of the Mars analog world”:

(Korea Aeropspace Research Institute/ESA/EPA)

●The Namib Desert in southern Africa, which is so dry that its main source of moisture is fog. Mars is also dry on the surface but has fog, McKay says. The desert also has huge sand dunes that resemble similar but much larger ones on Titan, a moon of Saturn.

(Tony Karumba/Agence France-Presse/Getty Images)

●Ol Doinyo Legai volcano in Tanzania. The volcano spews out carbonite lava, which, unlike basalt lava found in other volcanoes on Earth, is very runny — sort of like “motor oil,” Nadis says. Such a flowing consistency might help to explain very long lava channels on Venus.

(Dima Gavrysh/Associated Press)

●Atacama Desert in Chile, which, based on a photo accompanying the article, sort of looks like Mars. It is so dry, with just a “damp” day or two each year, the magazine says, that “absolutely nothing grows.”


●Lake Untersee and Lake Vostok, both in Antarctica. These two extreme landscapes — both covered by ice — could hold clues to bacterial or microbial life out there.

(Stoyan Nenov/Reuters)

●Great Geysir in Iceland, which shoots hot water 200 feet into the air from an underground hot spring. Extraterrestrial geysers have been spotted on a moon of Neptune by Voyager 2 and on a Saturn moon by the Cassini spacecraft.

(John Ward Anderson/The Washington Post)

●Pico de Orizaba, a volcanic mountain in Mexico, with what the article says is Earth’s highest treeline, with pine trees growing more than 13,000 feet above sea level. “Every habitable world should have [trees],” McKay tells the magazine. “The trees of Pico de Orizaba can tell us how much we’d have to warm Mars in order to have trees growing near its equator.”

The photos of all these sites, with comparable spots from Mars and elsewhere, are quite compelling. But you’ll have to buy the magazine to see them or be a Discover subscriber to peruse them online.