Caves are accessible windows into the shallow subsurface, serving as transitional ecosystems between the photosynthesis-dependent surface and the deeper subsurface. Without a source of solar energy to ultimately power carbon (C) fixation (photolithoautotrophy), cave ecosystems are either reliant on surface-derived nutrients, recovering reducing power from the microbial oxidation of redox-sensitive...
If life exists on Mars, it likely resides in a deep subsurface environment. The Martian rocky subsurface is a primary target for the search for extraterrestrial life because it offers a stable habitat for microbial life. On Earth, the continental subsurface is a key astrobiological analog for understanding what properties...