lake and beyond
Looking for life on Mars
Amy Williams is looking for little green men . . . on Mars.
Well, not exactly. She’s actually searching for something much smaller on the Red Planet—bacteria.
At the University of California-Davis, Williams ’07 (Earth and Environmental Sciences) was part of the Mars rover Curiosity science team tasked to solve the biggest mystery of Mars—could it support life? As a geobiologist, Williams studies how microbial life interacts with the geologic record. In other words, she studies how life is preserved in fossils and how to detect bacterial fossils in the ancient rock record.
Now, with ink scarcely dry on her Ph.D., Williams will continue her work as a post doc at NASA Goddard Space Flight Center in Greenbelt, Md. There she’ll continue working on the rover team with Curiosity’s SAM instrument, or Sample Analysis at Mars, whose purpose is to evaluate the past and present habitability of Mars by exploring the chemistry of its surface.
In an extraordinary show of engineering acrobatics, the roving, analytical chemistry lab about the size of a Mini Cooper known as Curiosity was launched in November 2011 via an Atlas V rocket. About eight months later, the capsule-shrouded rover entered Mars’s atmosphere, and following a series of well-orchestrated stages, it parachuted, then with the help of rocket engine blasts and sky crane, it finally soft-landed on Mars August 6, 2012.
After six-wheeling it to the base of Mars’s Mt. Sharp, Curiosity with its SAM instrument has busied itself drilling, pulverizing, heating, sorting, and even tasting and smelling all manner of rocks and minerals it collects at the mountain that rises five kilometers from the valley floor of Mars’s expansive Gale Crater.
SAM, a microwave-sized collection of instruments onboard Curiosity, can detect organic carbon, which is the stuff of life, says Williams. “SAM is a series of mass spectrometers which can pick apart the compounds in a rock sample,” she says. As a member of the SAM instrument team, Williams basically tells SAM to measure the mass spectrum of a rock sample in order to tease out the individual components. “That’s pretty cool—instructing a rover on another planet to do something that complex.”
It’s one thing to parse the bits into their separate compounds, but what then? That’s where Williams’s data interpretation skills come into play. Borrowing a quote from Carl Sagan, Williams says, ‘extraordinary claims require extraordinary evidence.’ She says, “On Mars we have a bunch of puzzle pieces and we have no idea how they fit together.” Using Mother Earth as a model, Williams and other scientists can make assumptions about the composition of rocks on Mars based on patterns that make up the geologic profile on Earth. In short, Williams looks at morphologic and chemical clues left by bacteria in the fossil record here on Earth to point to similarities on the surface of our planetary neighbor.
Highly social creatures, bacteria like to hang out in colonies, which makes it much easier to identify them morphologically in rocks. Williams compares the process to the algae bloom in Furman Lake. Once algae propagates, it’s easy to see. The macroscopic features she investigates happen to be encased in rock and minerals. “So far, I haven’t found evidence of life on Mars, but it’s important to understand what it looks like so we can keep looking for it,” she says.
Marking the trailhead to Williams’s geobiology trek was her Furman experience. “My time in EES was incredible. Doing a research project as an undergrad at Furman gave me a lot of insight into what would be expected of me in graduate school,” she says. One class in particular, biogeochemistry, taught by EES professor Dr. Brannon Andersen, set the stage for what Williams would later focus on for her PhD.
When Williams began working with the SAM instrument and looking at organic carbon, she realized that a professor, a class, a lab, or a research project can take you to surprising places later in life. “When I took O-Chem (organic chemistry) my sophomore year at Furman, I never would have guessed that I’d be working as an organic geochemist for a career. It’s really exciting—you never know where you’re going to end up when you take a broad range of classes at Furman. You might eventually apply things you never expected to . . . I never imagined I’d be working on a mission to Mars, but here I am.”
Her involvement with the River Basin Research Initiative at Furman as an undergraduate not only piqued her interest in aqueous geochemistry, it also allowed her to fast-track her master’s in biogeochemistry, a degree she earned in two years—one that takes most candidates three.
Part of Williams’s graduate studies at UC-Davis took her to NASA’s Jet Propulsion Laboratory (a division of Caltech) where she literally lived on Mars time (about 24 hours, 40 minutes per day) for several weeks. As images were downlinked to Earth, Williams says, “It was amazing. It was like waking up on Mars . . . because every Martian morning, you’re seeing things that no one’s ever seen before.”
For Williams, viewing uber hi-res images from Mars is close enough. When asked about her interest in space travel, Williams laughs and says, “You know, I was never really good with roller coasters . . . I figure going into space would be similar to that.”
With the rover, scientists expect to gain a better grasp on the weather conditions and radiation environment on Mars. Says Williams, “In some ways, the work the rover is doing is prepping us for manned missions to Mars in the future.” So for now, she is happy to study the rocks, searching for evidence of life. In a TEDxUCDavis talk she presented last year, “Exploring the Final Frontier,” Williams sums up by saying, “I want to know if those little green bugs are hiding in the rocks. Finding life on Mars would revolutionize our understanding of ourselves, our planet, and our place in the universe.”