[M-IS08] Astrobiology

[MIS08-06] Future astrobiological research in environments analogous to the extreme aridity and high-altitude conditions of the Atacama highlands

★Invited Papers

*Takahiro Segawa¹, Nozomu Takeuchi², Hidenori Takahashi³, Takashi Miyata³, Kenji Yoshikawa⁴ (1.University of Yamanashi, 2.Chiba University, 3.The University of Tokyo, 4.University of Alaska Fairbanks)

Keywords:Atacama highlands, Extreme environments, Microbial communities

Investigating life in Earth's extreme environments provides key insights for astrobiology, particularly in the search for extraterrestrial life on Mars and other planetary bodies. Understanding biological activity in subzero and hyper-arid conditions is crucial for assessing habitability across planetary bodies. NASA has identified extreme planetary environments, including subsurface ice, hyper-arid deserts, and salt-rich terrains on Mars and Europa, as key targets for astrobiological exploration. On Earth, the extreme aridity and high-altitude conditions of the Atacama highlands, one of the driest regions on Earth, provide a natural laboratory for investigating microbial survival strategies and potential biosignatures in Mars-analog environments. However, microbial studies in this region remain scarce due to inaccessibility and limited geospatial information. This study characterizes microbial communities in this extreme setting, providing insights for astrobiological research. Moreover, in tropical regions, high solar elevation induces diurnal freeze-thaw cycles, leading to the formation of an extremely shallow active layer. These temperature-driven phase transitions share similarities with environmental conditions on Mars, the Moon, and other planetary bodies. The Atacama highlands, with their extreme aridity and high elevation, serve as a valuable analog for extraterrestrial habitability studies.
We conducted field sampling and 16S rDNA analyses in the Atacama highlands, revealing distinct microbial communities adapted to extreme dryness and UV radiation. Future research will incorporate culture-based studies to further investigate microbial adaptations to extreme dryness and high-altitude conditions, enhancing our understanding of potential extraterrestrial life.