They propose the use of an instrument called LIBS incorporated into the Perseverance robot, expanding its functions
The presence of life would be identified at some point in Martian history
LIBS allows, in addition to obtaining data immediately, sampling at a distance of up to seven meters
A research team from the University of Malaga (UMA) has validated the use of a system for detecting organic compounds in rocks on Mars. Specifically, they propose the use of an instrument called LIBS incorporated into the Perseverance robot, expanding its functions. If it now detects and analyzes inorganic matter on the Martian surface, in addition, it would indicate organic remains, with which it would be identified the presence of life at some point in Martian history.
The Perseverance rover robot was launched in July 2020 with the goal of collect and analyze samples from the surface of Mars using a suite of analytics technologies including LIBS.
In the article ‘Investigation on the origin of molecular emissions in laser-induced breakdown spectroscopy under Mars-like atmospheric conditions of isotope-labeled compounds of interest in astrobiology’ published in the journal Spectrochimica Acta Part B: Atomic Spectroscopy, the experts confirm that this material analysis model can also be a good option to confirm the presence of biological fingerprints on the neighboring planet in a fast and efficient way.
If any of these molecules were found on Mars, it would mean that there were nitrogenous, aromatic or amine compounds, organic molecules that would determine the presence of some form of life in the past.
Furthermore, the Perseverance analyzes rocks up to seven meters away, which multiplies the possibilities in the collection of samples that may be inaccessible. “Specifically, the system consists of the emission of a pulsed light beam on any surface in a that the temperature evaporates the material it contains and remains available to know its atomic composition with great precision “, tells the Discover Foundation the researcher from the University of Malaga, José Javier Laserna, author of the article.
The chemical composition of the rocks is always similar. What distinguishes one type from another is the percentage of the elements they contain, the structure and their atomic organization. If at some point in its formation or erosion it had been included in them some organic material would have left a mark.
This biosignature is what the experts intend to rescue by eliminating the possibility of obtaining confusing results due to the interaction of lthe atmospheric compounds that could intervene in the collection of the samples through LIBS, they have added.
Thus, experts propose this system as an option valid in the search for traces of carbon, hydrogen and nitrogen in its many formulas on the surface of Mars. Specifically, for the detection of radicals such as cyanogen (CN), dimer carbon (C2) or amines (NH). If any of these molecules were found on Mars, it would mean that there were nitrogenous, aromatic or amine compounds, organic molecules that would determine the presence in the past of some form of life.
THE MARCIANA BIOFIRM
However, recognizing organic residues in materials using the LIBS technique can be affected by various circumstances. For example, lthe presence of carbon dioxide in the Martian atmosphere interacts with the gases emitted from the materials at the time of sampling by LIBS, which it can cause confusion in the results.
Did Mars have life or not at some point since its formation?
Still, the experts have demonstrated in a simulated space in the laboratory the validity of the system in the identification of biosignatures in materials despite the complexity of the reactions of formation, fragmentation and evolution.
One of the complications that can occur in the analysis of samples is that carbon molecules are obtained, but that they are caused by external agents, like the very atmosphere of Mars, rich in carbon dioxide. However, experts have shown that the damage from surface gases is only marginal and that organic compound fingerprinting is reliable on the information provided by LIBS.
To confirm this, the study tested LIBS with a variety of background gases, specifically with terrestrial atmosphere, pure CO2 gas and simulated Mars atmosphere, acting on different organic compounds. In most cases, atmospheric components and inorganic carbon are within limits to obtain a measurable signal.
They also observed that atmospheric carbon can react with organic nitrogen, which confirms the possibility of identifying the presence of a biological compound containing nitrogen.
Although LIBS is not the ideal analytical method for the identification of organic molecules, in this case it is proposed as the first of the steps to discover them on Mars. The rugged terrain of the planet means that Perseverance does not have access to certain targets that may be of interest. However, LIBS allows, in addition to obtaining data immediately, sampling at a distance of up to seven meters.
Therefore, if LIBS detects the presence of organic material, it would be necessary to continue delving into the composition with other more precise methods such as infrared spectroscopy, with which a more detailed map of the sample would be obtained, and thus conclude whether or not Mars really had life at some point since its formation.