Scientist probes chance of life on Mars
By Chris Edwards
Jennifer Eigenbrode searches for life on Mars.
Jennifer Eigenbrode ('94) is searching for life on Mars. The biogeochemist and geologist has designed an experiment that will explore the likelihood of life existing there — perhaps 3.5 billion years ago, and possibly now. She says Lynn Fichter's JMU geology class in stratigraphy initially pointed her toward her research focus.
"Curiosity" on Mars
The experiment Eigenbrode proposed and developed for the NASA Goddard Space Flight Center in Greenbelt, Md., will be part of Goddard's Sample Analysis at Mars (SAM) suite of instruments on a mobile laboratory. Other NASA scientists are selecting sites on the Red Planet for the Mars Science Laboratory rover and explorer "Curiosity," to explore. MSL/Curiosity will launch in fall 2011 and land on Mars in summer 2012, where it will obtain and transfer data to Earth, via satellite, for at least two Earth years.
Though an artist's rendering gives Curiosity a Tinkertoy appearance, Eigenbrode says, "The belly of the rover is the size of a small compact car and the wheelbase is comparable to a large truck. It can drive over boulders one meter in size."
It will study all aspects of Mars' history.
Biomarkers of life
A Mars Daily article on Eigenbrode's project calls MSL's SAM component "one of the most complicated instruments ever to land on the surface of another planet." Its robotic arm will scoop up soil samples, insert them into a carousel of tiny tubes, slide them into an oven and heat them — releasing gases SAM can analyze "for potential biomarkers" (indications of sustenance of life).
A few billion years ago, Eigenbrode notes, Mars was more like Earth, with liquid water. "If large organic molecules exist on Mars, an experiment specifically designed to break these molecules apart into identifiable components will be useful for understanding potential sources (geochemical or biochemical) and surface processes on Mars." She hopes investigating the molecules' evolution and composition will "shed light on the planet's carbon cycle."
Eigenbrode tested the effectiveness of the chemicals tetramethylammonium hydroxide in methanol in releasing organic molecules from rocks analogous to those on Mars. Favorable results prompted the inclusion of her experiment on SAM.
If evidence supports life on Mars, she says, "then it will be important to understand how that life interacted with its environment and how the Martian biosphere evolved." However, "detection of life … will not be straightforward. We may make observations that are suggestive of life, but we'll need additional independent observations." Although MSL/Curiosity will remain on Mars, a future craft might return Martian sediment samples to Earth for more thorough inspection.
Could the findings help with the search for "Earth-like" planets beyond our solar system? Eigenbrode says, "Probably. The only biosphere that we know of is Earth, and we use this knowledge to help guide the detection of exoplanets that might support biospheres. If Mars ever supported life, then it would expand our concept of planetary scale biospheres — their operation and detection."
An educational path to exploration
A Pennsylvania native, Eigenbrode was an undergraduate research assistant in JMU's geology labs. She calls Cullen Sherwood's soils lab "most memorable," and Fichter's stratigraphy class triggered her interest in geological history. "Jen was an extremely perceptive, energetic, curious and driven individual," Fichter recalls. "She's just a gem."
Since she graduated, the JMU geology and environmental science department has doubled its faculty, drawn about 100 majors, and improved its earth science B.A. as an option for those who do not, like Eigenbrode, earn the geology B.S., Fichter notes.
After Madison, Eigenbrode worked for the U.S. Geological Survey, where climatology exploration proved "monumental." Next came graduate school at Indiana University. In climatology, she found, "I had just chosen a new career path that would become interdisciplinary. There would be no more geology, biology or chemistry — it all blended together into a single field of study, which opened doors to the possibilities of what I could explore." For her master's thesis, Eigenbrode studied a salt lake sediment record of climate change in California. "Little did I know that years later we would consider this an analog to ancient Mars environments."
Teaching a Meteorites and Planets course to undergrads led Eigenbrode to realize: "To become a professor, I had to get a Ph.D., so I did"— in geosciences, from Pennsylvania State. There, she says, "I was immersed in Earth-system science from day one." While teaching Evolution of the Biosphere, she put her finger on the topic that would drive her research — the evolution of microbial life on Earth and elsewhere. "Within a year, I had joined the newly formed NASA Astrobiology Institute and was on my road to becoming an astrobiologist studying molecular records of life stored in rocks and ice." Since arriving at her current post in 2007, Eigenbrode says, "As a scientist, I do my best to make opportunities to teach. There is nothing like seeing someone's face light up with that 'ah ha!' look, or using something you've taught them in their own way.