Mars Rocks Research Articles

Lessons Learned in Designing a Proposed Ultraviolet Sterilization System for Space

This paper presents a number of lessons learned while designing a proposed sterilization system for Mars Sample Return. This sterilization system is needed to inactivate any potentially hazardous Mars material on the exterior surface of the vessel containing sealed sample tubes filled with Mars rock cores, regolith and atmosphere. These returned samples would provide information on the geologic history of Mars, the evolution of its climate and the potential for ancient life. Mars Sample Return is categorized at Planetary Protection Category V Restricted Earth Return, so it is required to protect the Earth–Moon system from the biological impact of returning samples from Mars to Earth. This article reviews lessons learned in the development of a particular engineering implementation to support the protection of the Earth–Moon biosphere: the use of in situ ultraviolet LED illumination. The details of the biological efficacy of this approach or the policy-related impacts are outside of the scope of this manuscript. The lessons learned presented here include establishing design requirements for the system, the selection of a light source, optical design options, contamination control and approaches to thermal and power management.

RSU-Net: An Attention U-Net for Martian Rock Segmentation

Since rocks may collide with the rover or wear tires during the exploration mission of the Mars probe, and may contain rich geological information, identifying rocks in the scene is crucial for the navigation and obstacle avoidance of the Mars probe. Additionally, since the communication between the Mars rover and the earth is often intermittent and delayed during missions, it needs a certain degree of autonomy. Deep learning technologies such as semantic segmentation and target detection can meet this requirement to a certain extent, which facilitates the enhancement of safety and efficiency for the Mars rover. Rock segmentation is to divide the pixels of the rock from the image. However, the texture of the rock is often close to the texture of the surrounding sand, and some parts may be covered, so it is difficult to identify it correctly. To this end, this paper proposed RSU-Net (Rock Segmentation U-Net) and RSU-Net-L, which combine the SENet attention mechanism, and the latter achieves higher computational efficiency and inference speed by compressing the number of channels on the basis of the former. In addition, this paper established a dataset, MarsRock, for Mars rock segmentation to help the Mars rover for visual navigation. Its images come from “Tianwen-1”, which contains 1194 images, and each image has a corresponding rock label. And our experiments on the MarsRock dataset show that RSU-Net can achieve 99.07% accuracy and 67.71% F1-score. RSU-Net-L can achieve 98.99% accuracy and 66.67% F1-score while diminishing the number of parameter count by 43.7% and the number of FLOPs by 43.6%, while the FPS can reach 12.01 on a single RTX6000-24GB GPU.

Design and Experimental Study of a Drilling Tool for Mars Rock Sampling

Martian rocks contain crucial information about the genesis of Mars and the historical evolution of Martian climate change. Consequently, extracting and examining Martian rocks are pivotal in advancing our comprehensive understanding of the red planet. However, the current core drill string is prone to wear and tear, and the samples are susceptible to thermal denaturation. To address these challenges, we introduce two novel types of drill bits, the conical straight junk slot and the conical spiral junk slot, both employing impregnated diamond as the primary material. Comparative experiments were meticulously conducted to evaluate the influence of different junk configurations on drilling parameters, including speed, abrasion resistance, drilling force loading, and sample temperature rise. The findings unequivocally demonstrate the superior performance of the spiral junk slot. Furthermore, simulations were performed to examine the drilling process on basalt using a fixed configuration drill bit, validating the occurrence of the sample temperature rise. The research presented in this paper offers valuable programmatic references and essential data support for future Martian rock coring drilling missions.

RESEARCH OF MARLY ROCKS ON THE TERRAIN FORECASTED FOR CONSTRUCTION OF SILOS OBJECTS

<p>Complexity of geological terrain built demands different level of research in order to obtain all necessary characteristics for the establishing of connections between the structure of the objects and the terrain. Frequent changes of rocks in vertical profile and their irregular settling related to creasing of the terrain during geological history makes choosing representative parameters harder. Layers of similar characteristics that are interconnected are separated into geological environments by taking medium values of the parameters within that environment.</p> <p>During the research, for the purpose of constructing of the silos objects, boreholes were drilled in the axis of each silos to a depth of 10.0 m. In a small area, there is a complex structure of the terrain, which, in addition to changes in the lithological composition, is also dictated by tectonic activity. Directly in the hinterland of the research conducted with boreholes, there is an open terrain profile with a height of about 6.0 m. By connecting the layers from the investigation works and the open profile on the terrain, a clearer picture of their position on the narrow part of the terrain was obtained.</p> <p>Frequent changes of layers of marly rocks and sandstones and their synclinal deposition demanded separation of certain geological environments with layers of the same characteristics. In addition to taking samples for laboratory tests, field tests of the solubility of marly rocks in the void at different temperatures were also conducted. In parallel with the samples from the investigation works, samples from the open terrain profile were examined. The results showed a shorter dissolution time of marly rocks from the open terrain profile compared to the same rocks taken from the core of the borehole.</p>

DNA sequencing at the picogram level to investigate life on Mars and Earth

DNA is an incontrovertible biosignature whose sequencing aids in species identification, genome functionality, and evolutionary relationships. To study life within the rocks of Earth and Mars, we demonstrate, in an ISO5 clean room, a procedure based on nanopore technology that correctly identifies organisms at picogram levels of DNA without amplification. Our study with E. coli and S. cerevisiae DNA samples showed that MinION sequencer (Oxford Nanopore Technologies) can unequivocally detect and characterise microbes with as little as 2 pg of input with just 50 active nanopores. This result is an excellent advancement in sensitivity, immediately applicable to investigating low biomass samples. This value is also at the level of possible background contamination associated with the reagents and the environment. Cultivation of natural and heat-treated Martian analogue (MMS-2) regolith samples, exposed to atmospheric water vapour or in increasing water concentrations, led to the extraction of 600–1000 pg of DNA from 500 mg of soil. Applying the low detectability technology enabled through MinION sequencer for a natural low biomass setting, we characterised the dry MMS-2 and found few soil-related organisms and airborne contaminants. The picogram detection level and the procedure presented here, may be of interest for the future Mars sample Return program, and the life research and planetary protection studies that will be implemented through the sample safety assessment.

RockFormer: A U-Shaped Transformer Network for Martian Rock Segmentation

Martian rock segmentation aims to separate rock pixels from background, which plays a crucial role in downstream tasks, such as traversing and geologic analysis by Mars rovers. The U-Nets have achieved certain results in rock segmentation. However, due to the inherent locality of convolution operations, U-Nets are inadequate in modeling global context and long-range spatial dependencies. Although emerging Transformers can solve this, they suffer from difficulties in extracting and retaining sufficient low-level local information. These shortcomings limit the performance of the existing networks for Martian rocks that are variable in shape, size, texture, and color. Therefore, we propose RockFormer, the first U-shaped Transformer framework for Mars rock segmentation, consisting of a hierarchical encoder–decoder architecture with a feature refining module (FRM) connected between them. Specifically, the encoder hierarchically generates multiscale features using an improved vision Transformer (improved-ViT), where both abundant local information and long-range contexts are exploited. The FRM removes less representative features and captures global dependencies between multiscale features, improving RockFormer’s robustness to Martian rocks with diverse appearances. The decoder is responsible for aggregating these features for pixelwise rock prediction. For evaluation, we establish two Mars rock datasets, including both real and synthesized images. One is MarsData-V2, an extension of our previously published MarsData collected from real Mars rocks. The other is SynMars, a synthetic dataset sequentially photographed from a virtual terrain built referring to the TianWen-1 dataset. Extensive experiments on the two datasets show the superiority of RockFormer for Martian rock segmentation, achieving state-of-the-art performance with decent computational simplicity.

A novel empirical classification method for weak rock slope stability analysis

This study presents a novel empirical classification system for stability analysis of rock slopes in weak rock based on their geotechnical and geological properties. For this purpose, consideration is given to the marly rock slopes, which include three main groups of weak rock (lime marlstone, marlstone, and marly limestone). The 40 different slopes located in the South Pars special zone (Assalouyeh), southwest of Iran, are targeted in classification. To prepare comprehensive graphical stability charts for weak rocks, extensive field surveys, sampling, geotechnical laboratory tests, and ground measurements are conducted in slope sites. Using the findings of the study, empirical stability charts for slopes composed of weak materials were developed. The charts are associated with geotechnical indexes, geo-units’ weathering impact, and in-situ stress conditions. Using these graphical charts assists in investigating the stability condition of rock slopes and estimating the geotechnical characteristics of clay-based weak rocks such as marlstones.

Life beyond Earth: How will it first be detected?

An overview of the status and prospects of the search for life in the universe is presented. The search for life beyond the Earth is being carried out using a variety of techniques in three distinct realms of space. First is the study of habitable locations in the Solar System using spacecraft and robotic probes. Second is the detection of the global alteration of exoplanet atmospheres by metabolic processes of microbes, with targets typically Earth-like terrestrial planets within 20 or 30 parsecs. Third is a search for the signatures of technology from extraterrestrial civilizations, in the form of pulsed radio and optical signals, thermal footprints, or physical artifacts. Targets for this third search span a significant fraction of the galaxy. Rough estimates are made of the odds that each of these strategies will be successful and the timescale for that outcome. All the estimates assume that life will form given suitable conditions and chemical ingredients. The best near-term prospect for the detection of life is the detection of biomarkers in exoplanet atmospheres using the James Webb Space Telescope and a set of large, ground-based telescopes that will come online later this decade. Optimal chances of detection center on super-Earths orbiting red dwarf stars. The next best prospect will come from the search for relic traces of life in ancient Mars rocks returned to the Earth, early next decade. Subsequently, missions to several potentially habitable locations in the outer Solar System could detect biomarkers. The most exciting of these involves Titan, where biology would likely have a different biochemical basis than life on Earth. The strategy deemed least likely to succeed, having indeterminate odds of success, is the search for extraterrestrial intelligence, SETI, or more accurately referred to as the search for extraterrestrial technology. The technical capabilities to detect artificial radio and optical pulses has been increasing exponentially, but the parameter space of the search is enormous, and is it impossible to interpret the meaning of a null result. While SETI could succeed at any time, it's likely that life will first be detected on a relatively nearby exoplanet, using spectroscopic methods allied to high resolution imaging. The discovery, when it comes, will be one of the most important in scientific history.

A New Explanation for Organics on a Mars Rock That Fell to Earth

Organic molecules on a Martian meteorite have fueled nearly 30 years of scientific debate. New evidence suggests they were formed by Martian processes, offering more support for a once habitable environment on the Red Planet.

From machine learning to transfer learning in laser-induced breakdown spectroscopy analysis of rocks for Mars exploration

With the ChemCam instrument, laser-induced breakdown spectroscopy (LIBS) has successively contributed to Mars exploration by determining the elemental compositions of soils, crusts, and rocks. The American Perseverance rover and the Chinese Zhurong rover respectively landed on Mars on February 18 and May 15, 2021, further increase the number of LIBS instruments on Mars. Such an unprecedented situation requires a reinforced research effort on the methods of LIBS spectral data analysis. Although the matrix effects correspond to a general issue in LIBS, they become accentuated in the case of rock analysis for Mars exploration, because of the large variation of rock compositions leading to the chemical matrix effect, and the difference in surface physical properties between laboratory standards (in pressed powder pellet, glass or ceramic) used to establish calibration models and natural rocks encountered on Mars, leading to the physical matrix effect. The chemical matrix effect has been tackled in the ChemCam project with large sets of laboratory standards offering a good representation of various compositions of Mars rocks. The present work more specifically deals with the physical matrix effect which is still lacking a satisfactory solution. The approach consists in introducing transfer learning in LIBS data treatment. For the specific application of total alkali-silica (TAS) classification of rocks (either with a polished surface or in the raw state), the results show a significant improvement in the ability to predict of pellet-based models when trained together with suitable information from rocks in a procedure of transfer learning. The correct TAS classification rate increases from 25% for polished rocks and 33.3% for raw rocks with a machine learning model, to 83.3% with a transfer learning model for both types of rock samples.

System Dynamics Modeling of Innovation Ecosystem With Two Cases of Space Instruments

This article develops a system dynamics model for innovation ecosystems in the high-tech industry. The model emphasizes the interactions between high-tech enterprises, the government, and universities in the innovation process. In particular, we use two high-tech instruments, the Mars Rock Corer and the Soil Preparation System, in the aerospace innovations developed by Hong Kong Polytechnic University. These instruments are a byproduct of collaborations with the European Space Agency, Russian Space Agency, and China Space Agency. They span decades of space missions to the moon and Mars. Furthermore, we propose a three parities systems dynamics model to study innovation behaviors. This model can be used to study and analyze the stakeholders’ interactions in high-technology-oriented innovation ecosystems. Theoretical, computational, and simulation studies are also conducted to understand and evaluate the evolution of the ecosystem. The results demonstrate the feasibility and effectiveness of this approach, which can be applied in on a large scale and in complex space projects.

Predicting Human Operator’s Decisions Based on Prospect Theory

Abstract The aim of this work is to predict human operator’s (HO) decisions in a specific operational context, such as a cooperative human-robot mission, by approximating his/her utility function based on prospect theory (PT). To this aim, a within-subject experiment was designed in which the HO has to decide with limited time and incomplete information. This experiment also involved a framing effect paradigm, a typical cognitive bias causing people to react differently depending on the context. Such an experiment allowed to acquire data concerning the HO’s decisions in two different mission scenarios: search and rescue and Mars rock sampling. The framing was manipulated (e.g. positive vs. negative) and the probability of the outcomes causing people to react differently depending on the context. Statistical results observed for this experiment supported the hypothesis that the way the problem was presented (positively or negatively framed) and the emotional commitment affected the HO’s decisions. Thus, based on the collected data, the present work is willed to propose: (i) a formal approximation of the HO’s utility function founded on the prospect theory and (ii) a model used to predict the HO’s decisions based on the economics approach of multi-dimensional consumption bundle and PT. The obtained results, in terms of utility function fit and prediction accuracy, are promising and show that similar modeling and prediction method should be taken into account when an intelligent cybernetic system drives human–robot interaction. The advantage of predicting the HO’s decision, in this operational context, is to anticipate his/her decision, given the way a question is framed to the HO. Such a predictor lays the foundation for the development of a decision-making system capable of choosing how to present the information to the operator while expecting to align his/her decision with the given operational guideline.

Magnetic fabric in carbonatic rocks from thrust shear zones: A study from the Northern Apennines (Italy)

We present the results of an integrated structural and anisotropy of magnetic susceptibility (AMS) investigation in calcareous and marly rocks from thrust shear zones. A total of 17 sites from six localities along the frontal and oblique ramp of the Olevano-Antrodoco-Sibillini thrust and back thrust (Northern Apennines, Italy) were studied to investigate both magnetic fabric and structural characteristics of Cretaceous to Neogene calcareous and marly rocks. In most of the sites AMS is controlled by the paramagnetic minerals (prevailingly phyllosilicates), with minor contribution of ferromagnetic (sensu latu) ones. Structural analysis shows the presence of SC- and S-tectonites associated to predominant simple and pure shear, respectively. The combination of density diagrams and cluster analysis allowed discriminating the contributions of sedimentary and tectonic processes to the bulk magnetic fabric. Six different subfabrics were distinguished, related to the structural data and associated to deformation stages and regimes: A. sedimentary fabric; B. intersection lineation; C. magnetic foliation parallel to S planes with k1 parallel to the S/C intersection; D. k1 moving toward the slip vector; E. magnetic foliation parallel either to the S or the C planes, with k1 parallel to the slip vector or the transport direction; F. k1 parallel to extensional planes intersection. The magnetic foliation has a double tendency to parallelize to pressure solution cleavage (S) and shear planes (C), while the magnetic lineation tends to progressively align with the slip vector, except for pure-shear-dominated sites at less than 15–20 cm from the thrust, where it aligns with the transport direction. The magnetic fabric is dominated by simple shear deformation. The protocol applied for AMS analysis shows a great potential to unravel mixed sedimentary and/or tectonic features in magnetic fabrics. AMS can be considered as a useful tool in unravelling the variation of simple-pure shear deformation regime in shear zones.

Black hole collision, funding disruption and Mars rocks

Black hole collision, funding disruption and Mars rocks

Assessment of the probability of microbial contamination for sample return from Martian moons II: The fate of microbes on Martian moons

This paper presents a case study of microbe transportation in the Mars-satellites system. We examined the spatial distribution of potential impact-transported microbes on the Martian moons using impact physics by following a companion study (Fujita et al., in this issue). We used sterilization data from the precede studies (Patel et al., 2018; Summers, 2017). We considered that the microbes came mainly from the Zunil crater on Mars, which was formed during 1.0–0.1 Ma. We found that 70–80% of the microbes are likely to be dispersed all over the moon surface and are rapidly sterilized due to solar and galactic cosmic radiation except for those microbes within a thick ejecta deposit produced by natural meteoroids. The other 20–30% might be shielded from radiation by thick regolith layers that formed at collapsed layers in craters produced by Mars rock impacts. The total number of potentially surviving microbes at the thick ejecta deposits is estimated to be 3–4 orders of magnitude lower than at the Mars rock craters. The microbe concentration is irregular in the horizontal direction due to Mars rock bombardment and is largely depth-dependent due to the radiation sterilization. The surviving fraction of transported microbes would be only ∼1 ppm on Phobos and ∼100 ppm on Deimos, suggesting that the transport processes and radiation severely affect microbe survival. The microbe sampling probability from the Martian moons was also investigatesd. We suggest that sample return missions from the Martian moons are classified into Unrestricted Earth-Return missions for 30 g samples and 10 cm depth sampling, even in our conservative scenario. We also conducted a full statistical analysis pertaining to sampling the regolith of Phobos to include the effects of uncertainties in input parameters on the sampling probability. The most likely probability of microbial contamination for return samples is estimated to be two orders of magnitude lower than the 10−6 criterion defined by the planetary protection policy of the Committee on Space Research (COSPAR).

Mid-infrared spectroscopy of planetary analogs: A database for planetary remote sensing

The MERTIS (MErcury Radiometer and Thermal Infrared Spectrometer) instrument onboard the ESA/JAXA BepiColombo mission will provide mid-infrared data, which will be crucial to characterize the surface mineralogy of Mercury. In order to interpret the results, we are creating a database of mid-infrared spectra. As part of a study of synthetic glasses which are to serve as analog materials for the interpretation of remote sensing and modeling data, we present mid-infrared data for analog materials of Mercury regolith, surface and mantle compositions. In addition, we provide data for similar analogs of Earth, Moon, Venus, and Mars rocks for a coherent picture.The analog samples have been first characterized by optical microscopy, Raman spectroscopy and EMPA. Powdered size fractions (0–25 μm, 25–63 μm, 63–125 μm, and 125–250 μm) were studied in reflectance in the mid-infrared range from 2.5 to 18 μm (550 to 2000 cm−1), additional micro-FTIR analyses were also obtained.Results for the size fractions of the surface and regolith analogs for Mercury show typical features for amorphous material with Christiansen Features (CF) at 8–8.1 μm, Reststrahlen Bands (RB) at 9.8–9.9 μm, and the Transparency Feature (TF) at 12 μm. The six bulk silicate Mercury analogs have varying CF positions from 8.1 to 9 μm, with RB crystalline features of various olivines dominating in most samples. Similarly, bulk silicate analogs of the other planetary bodies show glassy features for the surface analogs with CF from 7.9 μm (Earth Continental Crust) to 8.3 μm (Lunar Mare), strong RB from 9.5 μm (Earth Continental Crust) to 10.6 μm (Lunar Mare and Highlands). TF are usually very weak for the glassy analogs.Bulk silicate analogs for the other planetary bodies are again dominated by crystalline olivine features. Trends between SCFM (SiO2/(SiO2 + CaO + FeO + MgO)) index reflecting polymerization, CF and RB positions, and the SiO2 contents in previous studies are basically confirmed, but there is indication that several samples (Moon Mare and Highlands) do not follow the trend observed for low SiO2 samples and the RB position in earlier studies. Comparison with a ground based mid-IR spectrum of Mercury demonstrates general similarity in band positions with glassy Mercury surface and regolith material, and a chondrite based model of the planet. However, no mix so far can explain all spectral features.

The Fate of Lipid Biosignatures in a Mars-Analogue Sulfur Stream

Past life on Mars will have generated organic remains that may be preserved in present day Mars rocks. The most recent period in the history of Mars that retained widespread surface waters was the late Noachian and early Hesperian and thus possessed the potential to sustain the most evolved and widely distributed martian life. Guidance for investigating late Noachian and early Hesperian rocks is provided by studies of analogous acidic and sulfur-rich environments on Earth. Here we report organic responses for an acid stream containing acidophilic organisms whose post-mortem remains are entombed in iron sulphates and iron oxides. We find that, if life was present in the Hesperian, martian organic records will comprise microbial lipids. Lipids are a potential sizeable reservoir of fossil carbon on Mars, and can be used to distinguish between different domains of life. Concentrations of lipids, and particularly alkanoic or “fatty” acids, are highest in goethite layers that reflect high water-to-rock ratios and thus a greater potential for habitability. Goethite can dehydrate to hematite, which is widespread on Mars. Mars missions should seek to detect fatty acids or their diagenetic products in the oxides and hydroxides of iron associated with sulphur-rich environments.

A novel induction-based device for the measurement of the complex magnetic susceptibility

A device named magnetic susceptometer for a complete determination of the magnetic complex susceptibility of materials and minerals has been conceived and manufactured as a complement for the in situ characterization of rocks during high resolution magnetic prospections. In this work a device and its capabilities for susceptibility measurements are described, the calibration performed with artificial samples, and the values of real and imaginary susceptibility of natural samples in a range comprising: χ=10−4 to 10−7 [SI], representative of Earth and also Mars rocks.

Criteria for defining the required duration of a creep test

Time-dependent behaviour of some types of rocks is of the “creep” type, in particular in underground works, mining works, and in measuring procedures of rock properties. Tests used for defining material parameters or parameters relevant to defining a failure or behaviour of a material in the plastic state are usually of significantly shorter duration than the creep test. The duration of creep tests may vary from several hours to several years depending on the material being tested and the phenomenon that is the subject of the research. The required duration of the creep test, which provides reliable definition of the time-dependent material parameters of the rheological model, is a theoretical but also practical issue. The theoretical issue relates to establishing criteria for defining the required duration of the creep test. The practical issue relates to minimizing the duration of the creep test from which the necessary material parameters of the rock mass are obtained for correct numerical calculations. This paper proposes criteria for defining the required duration of a rock creep test, based on analysis of the results of unconfined uniaxial compression tests performed on marly rock samples.

Cracks in Martian boulders exhibit preferred orientations that point to solar-induced thermal stress.

The origins of fractures in Martian boulders are unknown. Here, using Mars Exploration Rover 3D data products, we obtain orientation measurements for 1,857 cracks visible in 1,573 rocks along the Spirit traverse and find that Mars rock cracks are oriented in statistically preferred directions similar to those compiled herein for Earth rock cracks found in mid-latitude deserts. We suggest that Martian directional cracking occurs due to the preferential propagation of microfractures favourably oriented with respect to repeating geometries of diurnal peaks in sun-induced thermal stresses. A numerical model modified here with Mars parameters supports this hypothesis both with respect to the overall magnitude of stresses as well as to the times of day at which the stresses peak. These data provide the first direct field and numerical evidence that insolation-related thermal stress potentially plays a principle role in cracking rocks on portions of the Martian surface.