[astro-ph.IM] Methane (CH4) is one of the most enigmatic and potentially consequential trace gases detected on Mars, having demonstrated apparent seasonality, localized plumes, or, depending on who you ask, never conclusively detected at all.
While the Martian methane mystery remains unsolved, it has sparked a vibrant area of astrobiology research exploring whether microbial methanogenesis — one of the simplest and most ancient metabolic pathways — could plausibly proceed under various extreme physicochemical conditions characteristic of the Martian shallow subsurface. The emerging consensus is a cautious but compelling “possibly”.
These findings elevate methanogenesis as both a top priority candidate biosignature for extant life detection and a justification for urgently advancing in situ instrumentation capable of definitively detecting CH4 and constraining its origin, biotic or otherwise
Rachel L. Harris
Comments: White paper submitted to the Mars Exploration Program Analysis Group (MEPAG) Search for Life Science Analysis Group (SFL-SAG) Report
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP); Populations and Evolution (q-bio.PE)
Cite as: arXiv:2610.24082 [astro-ph.IM] (or arXiv:2610.24082v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2610.24082
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Submission history
From: Rachel Harris
[v1] Fri, 16 Oct 2026 18:08:16 UTC (222 KB)
https://arxiv.org/abs/2610.24082
Astrobiology,
