Planetary geologist Nathalie Cabrol was smitten at an early age by the draw of adventure and uncharted territory. Like the organisms she seeks, Cabrol is an extremophile—drawn to extreme environments and the lessons these landscapes offer about the persistence of life. Through several personal chapters and across three scientific disciplines, Cabrol has crafted a career that accommodates her intellectual and exploratory wanderlust. Her pathway has, in true pioneering fashion, challenged her to weather cycles of joy, frustration, and the unknown.
Nathalie Cabrol at Laguna Blanca (elevation 4,340 meters), Chile, 2006, prior to scuba diving in Licancabur Lake.
Photo: High Lakes Project: SETI CSC/NASA ARCS/NASA Astrobiology Institute
Cabrol emerged first as a planetary geologist working at NASA, interested in understanding the evolution of water on Mars. Next, she ventured into astrobiology, selected the landing site for NASA’s Mars rover “Spirit,” and boldly searched for life in high-altitude lakes atop Andean volcanoes, where conditions are similar to those in Mars’ history. On these peaks, she found organisms thriving despite low oxygen levels and harsh ultraviolet radiation.
Now, Cabrol is embarking on a different, more Earth-centric journey as she measures the effects of climate change on these mountain ecosystems, while still casting an eye toward the red planet. Along the way, she’s earned an armful of NASA achievement awards and a 2008 citation by Mental Floss as one of the “new Einsteins”—the same year she authored a staggering 17 scientific papers.Appropriately enough, locating Cabrol’s cozy office—which she shares with her husband, civil engineer and geologist Edmond Grin—is an expedition in itself. After passing two security checkpoints and a huge aircraft hangar, the path ends on the northeastern side of NASA’s Ames Research Center in Mountain View, California. Cabrol, 47, is further tucked away in a corner of the distant building. Here, she weathers the storms science inevitably brings by following her irresistibly sunny temperament and internal spiritual compass.
“I don’t think I’ve ever seen Nathalie when she wasn’t smiling,” says colleague Seth Shostak, senior astronomer at the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View. “She’s very good-natured. That’s remarkable, because most people aren’t.”
The day she sat down to share her journeys, however, found Cabrol temporarily grumpy. “I am pissed off. I’m trying to be zen,” she says, sighing. “I’m usually a very positive person, but we all have our moments.”
Cabrol is trying to track down money. For years, her research on extreme environments has straddled NASA’s Astrobiology Institute and the SETI Institute, where scientists focus on finding intelligent life elsewhere in the universe. Cabrol has bridged that gap since 1998, when she became a principal investigator at SETI and set off in search of unfriendly territory. Probing the limits of organismal survival on this planet helps scientists define potentially life-supporting extraterrestrial environments, such as the ice-covered ocean on Jupiter’s moon Europa or the methane-rich landscapes on Titan, one of Saturn’s moons.
“Nathalie set the bar high when it comes to pioneering investigation,” says SETI Institute chairman emeritus Frank Drake, noting her challenging field expeditions to Lake Licancabur in the Chilean Andes. Cabrol went free diving in the high-altitude lake several times in 2003 and 2004 and holds the unofficial record for the highest altitude free dive. She was, at the time, searching for extremophiles—microbes capable of surviving in daunting environments. A frigid, UV-blasted lake more than 5900 meters (nearly 20,000 feet) above sea level definitely qualifies as daunting. “She’s fearless,” Drake continues. “She’s finding extremophiles in places that have not been studied and that are very hard to get to.”
Back in her office, her cloudy mood passes quickly and Cabrol’s spirits soar as she settles in to describe some of her adventures. Her musical French accent and delicate gestures color the portrait of a professional challenge-seeker.
“I’m a very grounded mystic. My church is all around me,” she says, her darkly shadowed eyes glittering like the stars she loves. “Especially in the Andes, when you just have to look up at the sky and see two galaxies in front of you, and Orion upside down.” This “upsets very much my Chilean friends, qho tell me it’s not upside down,” she adds.
Like the peaks she has learned to scramble up—courtesy of her mountaineering husband—Cabrol’s accomplishments keep mounting. As a graduate student in France, she was the first to study Mars’ Gusev Crater in detail, beginning in 1986. This impressed Valery Barsukov of the Soviet Academy of Sciences, and in 1990 he invited her to give a talk in Moscow, since the Soviet space program was thinking of sending a spacecraft to Mars. At the end of her talk, Cabrol recalls, “Baruskov stood up and he looked at me and said, ‘Well, now I have a problem. I don’t think we need to go to Gusev anymore because Nathalie knows everything!’”
Thirteen years later, Cabrol successfully argued for Gusev as the landing site for NASA’s Spirit rover, which touched down on the red planet in 2004. She also helped direct the development of robotic exploration technology for the rover “Nomad” in the Atacama Desert. “Before I even thought about it, I said, ‘yes,’" Cabrol recalls. "Then I sat down and thought, ‘Oh my God, what have I done? It’s only a multi-million dollar mission!’”
Ultimately, Cabrol succeeded in finding life where others thought it would be impossible: in those shallow inhospitable Andean lakes, more than three miles above sea level. In her relatively short career, she’s mentored more than a dozen students and given more than 400 lectures internationally, charming audiences with her tales of adventure. The only inspiration she needs to meet her goals, Cabrol says, is in the sky. “Just look up. That’s the best motivation in the universe.”
Moon walks and Jupiter cycles
Raised in a Paris suburb, Cabrol knew she was destined to explore other worlds, even as a girl. On July 20, 1969, her mother let her stay up late to watch Neil Armstrong and Buzz Aldrin walk on the moon. “We were on the couch and it was three o’clock in the morning in France. But we watched, the two of us,” Cabrol says. “I was five years old when I said to my mom, ‘This is what I want to do.’”
She started studying geology because she loved rocks, and math blocked her progress in astronomy. She conquered math in her twenties, cut a trail into astronomy and earned her PhD in 1991, at Sorbonne University. At the time, even before the field officially existed, Cabrol was a planetary geologist, someone who studies geological features on planets and moons. This made finding a job difficult: “When I applied for a position in geology, they told me I was an astronomer. When I applied for a position in astronomy, they told me I was a geologist,” she says with a sigh.
In 1994, Cabrol left France to work at NASA as a post-doctoral researcher, a planned nine-month stint. At the end of it, NASA asked her to stay. “They basically were asking me if I wanted to receive the biggest Christmas present I ever had,” Cabrol recalls.
Her first years were marked by successful grant applications and by earning SETI Institute principal investigator status in 1998, one of only a handful available.
Then, she abruptly hit a rough patch. Cabrol was struggling to navigate a competitive field, trying to write papers and proposals in a foreign language, and doing it all without the safety net she’d had as a post-doctoral researcher. “It was really, really difficult,” she says. “I had to make it work. I had left everything,” referring to both France and her parents, with whom she’d lived until moving to California at age 31. “I put 10,000 kilometers between them and me—and I was staying here. That was tough for them. So I had to make it work, to make it worth it.”
Cabrol, a swimmer who learned to free dive in the Mediterranean, turned to the water for comfort. She swam daily, for three months. “I cried so much. I’m not a crier,” she says. “At the beginning, there was more water coming out of my eyes than in the swimming pool. But after awhile, that went away and when I got out, I knew what I wanted to do.”
She wanted to study Earthly landscapes with conditions analogous to those on Mars. By 2001, she had funding from NASA for her work in these harsh environments, and in 2002, Cabrol began scrambling up Andean volcanoes in search of life.
Friend Brenda Simmons describes Cabrol as highly determined and dedicated to her research. “Nathalie is someone whom I've watched follow her dreams and her convictions to very successful outcomes,” Simmons says.
Following her dreams leads Cabrol out of periodic slumps and onto new ground. Those happen about every 10 years with the frequency of “Jupiter cycles,” she says, and force her to find a direction for the next chapter of her life.
“I have a very deep faith in the fact that if I dream hard enough, things will become reality,” Cabrol says. “We are actually designing the life we are living, for good and bad.”
Martian sunsets and diamond lakes
In cyclical fashion, Cabrol also returned to the focus of her early work: Mars’ Gusev Crater. In 2003, she argued for its selection as a landing spot for the Mars Spirit Rover, tasked with studying Martian geology. The crater appeared to be a dried-up lake bed, and scientists hoped it would provide clues to the history of water on the red planet.
“Nathalie was very astute in selecting the landing site for the Spirit rover,” Drake says. “She looked at jillions of photos from spacecraft from Mars and figured out what the signatures of a dry lake would be.”
But when Spirit landed in 2004, scientists found that the Gusev site didn’t contain as much information as other nearby formations. Drake says that isn’t evidence of failure, though: “We know so little, so it’s not surprising that you get surprised.”
However, scientists still found evidence for the past presence of water on Mars in the rocks littering the planet’s red slopes, and Spirit recorded a Martian sunset from inside the crater. Pointing to Cabrol’s expertise in geology, Shostak says her work is impressive. “She clearly knew a lot about lakes on a world that no human has been to.”
Now, in 2011, Cabrol also knows a lot about lakes on this world, too—lakes seldom visited by humans and almost never explored. To find out if life had a fighting chance on Mars at some point in the planet’s history, Cabrol headed to the best Earth analog she could find: high-altitude Andean lakes, 4,000 to 6,000 meters above the Chilean plateau. The lakes originally intrigued Cabrol because of their similarity to early Martian environments: cold, watery oases bombarded with UV radiation.
“We’d titled the project, ‘The limits of life in the highest lakes on Earth’—and I thought it would be a really short-lived project because the conditions were so nasty,” Cabrol says, smiling.
The fifth-highest lake in the world, Licancabur, is in the Andes at the top of the cone-shaped Licancabur volcano, at 5,916 meters above sea level. Cabrol led expeditions to the region between 2002 and 2009, free diving into the lake for several years before earning her SCUBA license. She’d avoided that training for years, she explains, because she preferred the silence of free diving and feared the pressurized air tanks. But oxygen levels at that altitude are so low she wasn’t able to stay underwater long enough without the SCUBA gear.
Diving in Lake Licancabur is “probably one of the most beautiful, magnificent memories I have,” Cabrol recalls. “The water sparkled—like with thousands of diamonds, and you could see every single ray of sun. You could see each ray at the surface, and at the bottom,” five meters down.
On those dry, chilly volcanic peaks, Cabrol and her team discovered evidence of abundant life, including flamingos and a massive field of fossilized microbial mats, called stromatolites. They collected the first microorganisms from the lake. She also found a 10,000-year-old arrowhead on the shores of Laguna Blanca, which she donated to a museum in San Pedro de Atacama, Chile.
“Life was everywhere. Big and small,” she says, recalling her astonishment at the richness of organisms at those altitudes, despite the harsh conditions. “I sat on one of the stromatolites and I looked at Edmond and said, ‘Where do we start?'”
Now, the first phase of the high lakes project has met it goals and ended, leaving Cabrol in one of her periodic Jupiter troughs, writing grants and finding new directions. But she misses the lakes and would love to go back. “Part of my soul is over there, I know that. But you cannot live with the past, or else the past imprisons you. To continue to live is to move on,” she says.
To Mars and back
Cabrol wants to continue exploring Mars and other planets—but also would like to find solutions for problems like climate change on Earth. She wants to study how climate change affects the high lakes environments, recognizing that similar shifts may have occurred during Martian history. “I can be useful here and now, and project my spirit and thoughts into the future with planetary exploration,” she says.
“The only thing I can do is think positively. And breathe, from time to time. You know, free divers, we don’t breathe all that much.”
Would she go to Mars if the opportunity arose?
“Oh yeah. Of course yes. Of course yes,” she says matter-of-factly. This is perfectly in tune with one of friend Brenda Simmons’ favorite images of her: a black-and-white photograph of Cabrol wearing dark glasses and dressed in black, arms akimbo. “The caption reads in French, ‘If I want to hold a Mars rock, I’d rather get it myself.’”
Cabrol sent an update in May 2011: She is beginning a new phase of the High Lakes project, while continuing to work on rovers in the Atacama desert. Now, she will explore the effects of rapid environmental change on life in the Andes and on early Mars habitats. Cabrol also will work on developing strategies for missions to the seas on Titan, one of Saturn’s moons. “This is so exactly what I wanted,” she says. “The new chapter is now open, and it includes both planetary exploration and exploration of our own planet.”