Bioenergetic Modeling of Methanogens In Europa's Subsurface Ocean Environment
Abstract
The ultimate goal for many is to find life elsewhere in the universe, whether it be in our own Solar System or further, but current technological, physical, and/or other limitations prevent a definitive answer. Furthermore, the subsurface oceans on the icy moons of our Solar System, specifically Europa, are manifestly of great astrobiological interest. Modeling these environments and the growth of putative organisms within them can aid in this grand endeavor of understanding and identifying other habitable and inhabited worlds. Simulating the interactions of these organisms with each other and with the available environmental nutrients and substrates, as well as the accessible energy sources and sinks, is crucial for not only determining the habitability potential of such environments but also developing a theoretical framework for later use during comparisons with direct observation and data collection. To elaborate on this theme further, ascertaining putative properties of ecosystems from a bioenergetic standpoint is valuable for the following two reasons: (1) interpretation and analysis of data from future missions, such as Europa Clipper and JUICE, and (2) theoretical predictions of what to expect in these ecosystems, thus potentially aiding in selecting the design and functionality of future missions and instruments. In this study, modeling is achieved through use of the python code package NutMEG (Nutrients, Maintenance, Energy and Growth), with the chief objective to simulate methanogens in the subsurface ocean environment of Europa, whose ocean may be more acidic relative to Earth (among other properties). The preliminary results presented show that the power supply available per cell varies with temperature, but variations in pH have little to no effect. The results also show that the theoretically available maintenance power and specific combinations of ocean pH and temperature meet the criteria for methanogens to survive in a relatively habitable environment. Future work includes expanding this analysis to determine potential biomass evolution and final population sizes, determining concentrations of produced biosignatures, and to perform similar modeling and simulations on other habitable environments.
- Publication:
-
AAS/Division for Planetary Sciences Meeting Abstracts #55
- Pub Date:
- October 2023
- Bibcode:
- 2023DPS....5531510G