Changing Planet

The Dry Edge of Life: Studying “Martians” in Chile

I recently spent a week with a group of astrobiologists studying life in the Atacama Desert of northern Chile.

This is extraordinary, because the Atacama is the driest place in the world. The average annual rainfall is one millimeter, and decades can go by between rain events.

There’s not much life to study. It’s too dry for plants and animals to survive in the desert’s hyperarid core. There are no insects, no lizards, no birds, no rodents. No trees, no shrubs, no cacti. Not even lichen. Nothing but dirt, rocks and salt flats.

To a large extent, the landscape has gone unchanged for 10 to 15 million years. It looks like pictures of Mars. (Related: “Chile Desert to Prepare Robot for Life on Mars.”)

NASA scientists interested in what life may have looked like on ancient Mars therefore spent several years trying to find bacteria living in the Atacama. (Related: “Viking Mission May Have Missed Mars Life, Study Finds.”)

The salt flats turned out to be the key. They’re not exactly flat—they’re filled with bizarre, knobby rocks made of halite (table salt). The locals call these knobs flores (“flowers”), because they grow over time. Rocks like these don’t form anywhere else on Earth—nowhere else is dry enough.

In 2005, in an unnamed salt flat near the site of a former nitrate mine, Jacek Wierzchos, a researcher from Madrid, discovered a novel species of photosynthetic bacteria living inside these salt rocks.

Occasionally at night, when the relative humidity in the air increases sufficiently, the halite rocks absorb moisture from the atmosphere, and microscopic pockets of liquid brine form inside them. Because halite is translucent, it allows some sunlight to penetrate into its interior, enabling photosynthesis while screening out harmful UV radiation.

The findings from studies of these halite flowers may help guide the future search for life on Mars. Conditions similar to those in the present-day Atacama may have existed on Mars in the past.

For more information, check out my field reports on the Astrobiology Magazine website.

Science writer and photographer Henry Bortman is the field research editor for the NASA-sponsored website Astrobiology Magazine. His work takes him on scientific expeditions to extreme environments around the world. He reports on research aimed at understanding the limits of life on Earth and finding evidence of life on other worlds.
  • Justin Morell

    Fascinating. And beautiful photos!

  • cdalton

    This is extremely interesting, salt flowers in a place where there is no life?

  • Yadvendra Singh

    i like it.its nice to see the life like these places.

  • Margaret Power

    Hey! What did you think of Chile? Did you go to Iquique? It was so neat to read your article.

  • Torbjörn Larsson, OM

    Amazing. One of the driest, and I think most diurnal temperature cycling (?) places on Earth and it helps hiding out in *salt* and salty brines!?

  • Darlene

    Justin do you have a facebook?

  • dua khan

    nice program

  • Becker, M.

    Truly amazing to witness endless survival-ability of life’s energies.

  • The Platzner Post


  • cheyne alvis formalejo

    very interesting place indeed! nice photos too

  • yasmin

    Congratulations for Jacek and his investigations!!! to find life in these halite rocks is just incredible and fascinating, it shows that all in this universe is “alive” …….for sure! thanks for sharing this really interesting article mr. Bortman.


    That’s nice picture

  • Lakhdar Still

    it’s fantastic places like this. But in Algiers there are better places than these, you could exploring it

  • Caitlin Liebmann

    Why we should always keep our minds open…

  • Angel Cantie

    Question, how did these flowers develope and stay uniform?

    • Henry Bortman

      Angel, they are not uniform. They come in many shapes and sizes. The formation process is described in my article “Islands of Life, Part III“.

  • Adrian Holmes

    I am trying to understand why I feel comforted by this!

  • Vikas Sharma

    I think spiritual rain could be caused over there with the help of Kundalini. I have done more than 15 years of research on this subject and think so that can cause climate change with the help of Kundalini.

  • Alex Krupa

    It is amazing ! Lives is everywhere !!
    Congratulation Jacek !!!!

  • Adam Bray

    Are these never found in caves? I’ve seen nodules that look identical to these, deep in caves along the border of georgia and tennessee. What particularly strikes me is the way the nodule is attached to the substrate underneath it–the ones in the caves were attached in just such a manner.

  • Henry Bortman

    Greg, the nearby mining activity and the presence of the bacteria is purely co-incidental. The bacteria have been found in several salars in the Atacama, not all of them near former mines. The organisms are considered novel because their genetic sequence differs significantly from that of any previously known bacteria. They have evolved to survive in a unique environment – inside salt rocks – that as far as is known do not form anywhere on Earth other than in the hyperarid Atacama.

  • Attia Nurani

    Much think in this world we never know until we research and traveling a place like Acatama. And finnaly we get knowledge to be come use for ourself. Beautiful photo Mr.

  • rosanautica

    Did you see any rocks there that seem to have moved–rocks that leave behind visible paths in the dirt? Would you know how that happens?

  • explora

    Hi Henry, very interesting article. We partly disagree with it. The Atacama Desert stretches for more than 1,000 km (600-miles) and it’s right a high percentage of this vast territory is to dry to have animals and plants. In spite of the geographic and climatic conditions of the desert, there are few and miraculous places all teeming with life, as are the ravines and oases which have formed around the small water courses that descend from the Andes… We invite you to to check this pictures out Best

  • […] (Related blog: “The Dry Edge of Life—Studying ‘Martians’ in Chile.”) […]

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