Curious About Life: Interview with Roger Summons
Roger Summons, of the Massachusetts Institute of Technology, is working with SAM to study potential organic material within the rocks of Mars.
What type of research do you usually do?
I study the preservation and the characteristics of organic matter in rocks, because organic matter carries information about the organisms that formed it. For example, on Earth we have organic matter preserved in the form of oil shale and coal. So it's possible to chemically characterize this material, which is biological in origin, and assign organisms or processes to certain components of the organic matter. In respect to petroleum, which is useful as an exploration tool, you can understand what sort of environment and what sort of organisms went into the material that comprises the material.
What sort of work do you do specifically with MSL?
Well, I'm on the SAM team working at JPL. Mostly I'm involved with the quadrupole mass spectrometer and the gas chromatograph. I'm also interested in the tunable laser spectrometer results, because if we do find organic in sediments, then we can use that instrument to observe the carbon isotopic patterns of that material.
I have more of an advisory role on the conduct of certain experiments. I try to have an overview of what else is going on with the mission, particularly the information that pertains to understanding what kinds of rocks are being investigated. The cameras, ChemCam, CheMin, APXS—all of those instruments give you information about the mineralogy and sedimentary environment of the sediments. That is important to deciding what sort of samples would be most prospective for organic carbon analysis.
I also have a laboratory component. At MIT, I have a mass spectrometer that serves as a partial analog of the SAM GCMS [the Gas Chromatographer and Quadrupole Mass Spectrometer]. It is fitted with a thermal desorption module that mimics the thermal desorption module that will be used for analysis of Mars soil. With our instrument at MIT, and the help of a post-doctorate fellow there, we are able to conduct analog experiments in real time.
We can take any mineral or Mars analog soil material, spike that material with particular organic compounds or any other substances that might be present on Mars, and do experiments that, partially at least, could mimic what is being done by the same instrument in real time. In this way, we are basically field testing or ground truthing the data that might be coming down from Mars, if we replicate that experiment and get the same result.
How can your work help to answer astrobiology questions?
Well, the principle aim of the mission is to determine if Mars is or was ever habitable. That is a very large question with many, many elements to it. If Mars were habitable in any significant way, we would expect to find organic residues of past life, or the building blocks or biosignatures for life. I mean, basically the research is all about biosignatures.