Summary and Reader Response Draft 03 of the ExoMars Drill Unit

In the article “The ExoMars Drill Unit” (2019a), the ExoMars drill unit was depicted to be a component of the ExoMars Rover and was developed to extract core soil specimens to a depth of two metres in an array of soil samples on Mars and transport them to the "inlet port" of the "Rover Payload Module". Vago et al. (2017, p. 492) denote the drill unit consisting of the drill tool, three extension rods, and Ma_MISS (“Mars Multispectral Imager for Subsurface Studies”) infrared spectrometer. The drill tool comes equipped with the specimen retrieval tool that includes a "shutter, movable piston", and temperature detectors (Vago et al., 2017). The drill Thermocouples are attached close to the tip of the drill to track temperature deviations in the sample receptacle. Ma_MISS signals are sent using the extension rods to the spectrometer on the drill unit's upper portion via optical and electrical connections. The Ma_MISS infrared spectrometer is built into the drill tool to scan borehole walls as the drill is operating. Ma_MISS also offers the potential to research soil “stratigraphy and geochemistry in situ” (Vago et al., 2017). European Space Agency (2019b) states that biomarkers and fossil groups found subterraneous or within rock surfaces are the best indications of early life on Mars. As a response to the claim by the European Space Agency (2019b), I believe that the ExoMars drill unit is necessary to preserve the biomarkers and fossil groups collected in the search for life on Mars.

In their research, Vago et al. (2017) highlight the importance of conserving the biomarkers and fossil groups located underground, because they represent the most comprehensive substantiation that life existed on Mars. The research article under the subtopic, heading: Chemical biosignature, describes that majority of Earth's biological material exists in the “form of carbonaceous macromolecules stored" underground, and the presence of those is more abundant in living organisms (Vago et al., 2017, p. 480). Subterranean, structural biopolymers such as lipids and proteins are stable for billions of years, whereas carbohydrates and proteins decompose fleetly once microorganisms die. Thus, the preservation of biomarkers collected from beneath the surface by the drill unit is vital to provide the highest probability for the presence of life on Mars.

Vago et al. (2017, p. 492) emphasize the importance of the Ma_MISS spectrometer for preserving deep specimens that may be altered after removal from their cold, subterranean environment. Ma_MISS and the spectrometers inside the ExoMars work together to prevent alterations of the samples during the drilling process. Ma_MISS will investigate the unexposed matter, while spectrometers in the ExoMars rover will collect data crucial to resolving rock formation conditions. As a result, these features and functions are pivotal to preserving the natural and unpredictable content of the sample, especially during radiation damage, ensuring pristine biomarkers for examining whether life exists.

While the drill unit seems sufficient for preserving identifiers for life on Mars, the article authored by Korablev et al. (2017) offers a different perspective. As stated in the article, trace gases such as methane, in Mar's atmosphere, are thought to be indicators of early or current biological or geological movement. “Planetary biota” will create a state of disequilibrium in the atmosphere that would indicate the presence of life on Mars (Hitchcock & Lovelock, 1967; Korablev et al., 2017). However, the level of disequilibrium must be far greater than what nonbiological processes can produce. According to Hitchcock & Lovelock (1967) and Korablev et al. (2017), identifiers for life on Mars can be obtained in the atmosphere.

In conclusion, the ExoMars drill unit is necessary to obtain and preserve biomarkers used to identify life on Mars. However, verification for the compilation of possible biosignature discoveries may require further scrupulous analyses, one our present technology is not capable of (Vago et al., 2017, p. 499-500). Even though well-preserved biomarkers underground present the best way of detecting the presence of life on Mars, technology today is not advanced enough to determine the precedence of sample collection to prove existence.

References

 

European Space Agency. (2019a, September 1). The ExoMars drill unit. ESA.

https://exploration.esa.int/web/mars/-/43611-rover-drill

 

European Space Agency. (2019b, September 1). Searching for signs of life on Mars. ESA.

https://exploration.esa.int/web/mars/-/43608-life-on-mars

 

Hitchcock, D. R., & Lovelock, J. E. (1967). Life detection by atmospheric analysis. Icarus, 7(1–3), 149–159.

https://doi.org/10.1016/0019-1035(67)90059-0

 

Korablev, O., Montmessin, F., Trokhimovskiy, A., Fedorova, A. A., Shakun, A. V., Grigoriev, A. V., Moshkin, B. E., Ignatiev, N. I., Forget, F., Lefèvre, F., Anufreychik, K., Dzuban, I., Ivanov, Y. S., Kalinnikov, Y. K., Kozlova, T. O., Kungurov, A., Makarov, V., Martynovich, F., Maslov, I., . . . Zorzano, M. P. (2017). The Atmospheric Chemistry Suite (ACS) of Three Spectrometers for the ExoMars 2016 Trace Gas Orbiter. Space Sci Rev, 214(7), 1–62.

https://doi.org/10.1007/s11214-017-0437-6

 

Vago, J. L., Westall, F., Pasteur Instrument Teams, Landing S, Coates, A. J., Jaumann, R., Korablev, O., Ciarletti, V., Mitrofanov, I., Josset, J. L., de Sanctis, M. C., Bibring, J. P., Rull, F., Goesmann, F., Steininger, H., Goetz, W., Brinckerhoff, W., Szopa, C., Raulin, F., Westall, F., . . . The ExoMars Project Team. (2017). Habitability on Early Mars and the Search for Biosignatures with the ExoMars Rover. Astrobiology, 17(6–7), 471–510.

https://doi.org/10.1089/ast.2016.1533