Mars Rover’s Organic Molecule Detector Validated with Desert Analogues.

A modified commercial laser desorption ionisation mass spectrometer, replicating the functionality of the Rosalind Franklin rover’s MOMA instrument, successfully detects organic standards within mineral matrices. Validation using Atacama Desert samples and synthetic mixes confirms its ability to characterise both mineralogical and organic signals relevant to Martian environments.

The search for evidence of past or present life on Mars receives a significant boost from advances in analytical instrumentation, specifically laser desorption ionisation mass spectrometry (LDI-MS). This technique vaporises minute quantities of material using a laser, then separates and identifies the resulting ions by their mass-to-charge ratio, revealing the chemical composition of a sample. A team led by Zachary K. Garvin and Sarah Stewart Johnson of Georgetown University, alongside colleagues from NASA Goddard Space Flight Center and Aerodyne Industries, detail in their work, ‘Application of a modified commercial laser mass spectrometer as a science analog of the Mars Organic Molecule Analyzer (MOMA)’, the development of a terrestrial LDI-MS instrument designed to mimic the functionality of the MOMA instrument scheduled to be deployed on the European Space Agency’s Rosalind Franklin rover in 2028. The instrument’s capabilities, validated using both natural samples from Mars-analogous environments and synthetic mixtures, promise to enhance pre-flight testing and data interpretation for the upcoming mission, ultimately aiding the search for organic biosignatures on the red planet.

Researchers have successfully adapted a commercially available laser desorption ionisation mass spectrometer (LDI-MS) to functionally replicate the capabilities of the Mars Organic Molecule Analyser (MOMA), a principal instrument aboard the Rosalind Franklin rover currently en route to Mars. This adaptation provides a vital platform for pre-flight testing and data generation, as direct access to the flight-qualified MOMA instrument remains limited.

The adapted LDI-MS demonstrates the capacity to detect organic standards embedded within complex mineral matrices, confidently identifying molecular structures even within intricate mixtures using tandem mass spectrometry (MS/MS). Tandem mass spectrometry involves multiple stages of mass analysis, allowing for structural elucidation of detected molecules. Validation of the instrument’s performance involved comparative analysis with an existing LDI-MS, alongside the examination of samples sourced from a Mars analogue environment, specifically the Atacama Desert in Chile. This desert’s arid conditions and geological composition closely resemble certain Martian terrains.

Crucially, the instrument can characterise both the mineralogical and organic components of synthetic samples, meticulously designed to mimic the composition of Martian surface materials. This capability allows researchers to simulate the anticipated Martian environment and refine analytical protocols. A critical calibration procedure utilising laser-induced breakdown spectroscopy (LIBS) establishes a correlation between laser energy, or fluence, and the resulting signal strength. LIBS involves focusing a high-powered laser onto a sample, creating a plasma that emits light, the analysis of which reveals the elemental composition. This calibration ensures accurate quantitative analysis when the MOMA instrument operates on Mars.

The adapted LDI-MS functions as a collaborative research platform, enabling the refinement of instrument parameters and the generation of essential pre-flight reference data. This work is fundamental to preparing for the Rosalind Franklin mission and maximising the potential for detecting and identifying organic molecules relevant to the search for extant or past life on Mars. The instrument’s capabilities significantly enhance the prospects for successful operation of the MOMA instrument and the achievement of the mission’s overarching scientific objectives.