21st-Century Astrobiology Missions Should Seek These High-Confidence Biosignatures

TL;DR

This white paper advocates for focusing on high-confidence, agnostic biosignatures such as biopolymers, homochirality, and chiral reactions in Martian subsurface ice to improve the unambiguous detection of extraterrestrial life.

Contribution

It identifies specific biosignatures and instrument concepts for future Mars missions to enhance biological detection capabilities.

Findings

Prioritized biosignatures for astrobiology missions

Instrument concepts targeting these biosignatures

Strategic framework for unambiguous life detection

Abstract

This white paper was submitted to NASA's Search For Life Science Analysis Group (SFL-SAG): To ensure that the first mission designed to seek signs of extant life since 1976 is able to produce an unambiguous biological interpretation, the SFL-SAG is tasked with identifying the most high-confidence, agnostic biosignatures which are targetable, detectable, and measurable in Martian subsurface mid-latitude ice. To aid in this effort, this white paper highlights three examples of target materials or phenomena, along with associated instrument concepts, which the SFL-SAG shall prioritize in its efforts to define the appropriate astrobiological strategy. These include 1) polyelectrolyte informational biopolymers, 2) macromolecular biological homochirality, and 3) chiral-specific metabolic reactions. The Agnostic Life Finding Association (ALFA) and University of Florida (UF) support the development of instrumentation that seeks these high-confidence biosignatures.