Amy Williams is looking for little green men . . . on Mars.<\/p>\n
Well, not exactly. She\u2019s actually searching for something much smaller on the Red Planet\u2014bacteria.<\/p>\n
At the University of California-Davis, Williams \u201907 (Earth and Environmental Sciences) was part of the Mars rover Curiosity science team tasked to solve the biggest mystery of Mars\u2014could 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.<\/p>\n
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\u2019ll continue working on the rover team with Curiosity\u2019s 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.<\/p>\n
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\u2019s 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.<\/p>\n
After six-wheeling it to the base of Mars\u2019s 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\u2019s expansive Gale Crater.<\/p>\n
SAM, a microwave-sized collection of instruments onboard Curiosity, can detect organic carbon, which is the stuff of life, says Williams. \u201cSAM is a series of mass spectrometers which can pick apart the compounds in a rock sample,\u201d she says.\u00a0 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. \u201cThat\u2019s pretty cool\u2014instructing a rover on another planet to do something that complex.\u201d<\/p>\n
It\u2019s one thing to parse the bits into their separate compounds, but what then? That\u2019s where Williams\u2019s data interpretation skills come into play. Borrowing a quote from Carl Sagan, Williams says, \u2018extraordinary claims require extraordinary evidence.\u2019 She says, \u201cOn Mars we have a bunch of puzzle pieces and we have no idea how they fit together.\u201d 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.<\/p>\n
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. \u00a0Once algae propagates, it\u2019s easy to see. The macroscopic features she investigates happen to be encased in rock and minerals. \u201cSo far, I haven\u2019t found evidence of life on Mars, but it\u2019s important to understand what it looks like so we can keep looking for it,\u201d she says.<\/p>\n
Marking the trailhead to Williams\u2019s geobiology trek was her Furman experience. \u201cMy 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,\u201d 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.<\/p>\n
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. \u201cWhen I took O-Chem (organic chemistry) my sophomore year at Furman, I never would have guessed that I\u2019d be working as an organic geochemist for a career. It\u2019s really exciting\u2014you never know where you\u2019re 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\u2019d be working on a mission to Mars, but here I am.\u201d<\/p>\n