From searching for extraterrestrial biosignatures to exploring the origins of life: A prebiotic chemistry perspective

The search for extraterrestrial life represents one of humanity’s most profound scientific endeavors. This review examines the role of prebiotic chemistry in our quest to detect extraterrestrial life. Analyzing diverse chemical pathways, including the Strecker synthesis, cyanide polymerization, and Fischer-Tropsch-type reactions, outlines how simple inorganic precursors may evolve into complex chemical reaction networks under non-biological conditions. While compounds such as amino acids are common in both abiotic and biotic contexts, discerning their origins requires an understanding of reaction mechanisms, environmental contexts, and the thermodynamic challenges of polymerization. Moreover, this review addresses the emergence of homochirality and the development of genetic systems, proposing that these phenomena may arise from dynamic prebiotic processes. Laboratory simulations of extraterrestrial environments are crucial in testing these hypotheses, providing insights into the potential trajectories from simple monomers to complex macromolecules under planetary surface and interstellar conditions. Ultimately, this review advocates for reassessing biosignature interpretation methods, underscoring the need for integrated, multifaceted approaches that consider both prebiotic chemical evolution and environmental context when evaluating the potential for life beyond Earth. This review examines the role of prebiotic chemistry in our search for extraterrestrial life. Through the analysis of disparate chemical pathways for molecular biosignatures and laboratory simulations of extraterrestrial environments, we could provide insights into hypotheses concerning the chemical evolution of life under interstellar conditions.