The abiotic baseline is the background level of abiotic processes — isotope fractionation, racemization, organic synthesis — against which any biosignature must be evaluated on a given world.
Higgins et al. (2026) demonstrate using enceladus as a case study that uncertainties in abiotic carbon-isotope cycling and amino acid racemization currently prevent definitive life detection. Critically, neglecting the abiotic baseline risks false negative life-detection claims (missed life), not just false positives. Reducing this uncertainty requires complementary geophysical constraints: internal temperatures (~10-100 C), rheology, lithology, initial organic inventory, and ocean transport timescales. See src-ocean-worlds-biosignature-framework-2026-05.
The concept is central to mission planning for europa-clipper, InvOW, and any future enceladus lander.