Table of contents

Executive summary

The scope of this deliverable is to:

(1) provide a comprehensive GIS archive including georeferenced orbital data (e.g., visible imagery, DEM, geomorphological maps) of the future landing site for upcoming ESA/Roscosmos’ ExoMars and NASA’s Mars2020 rover missions: Oxia Planum and Jezero crater, respectively.

(2) to provide an integrate Virtual Reality (VR) application featuring both sites, where the users can visualize and explore within a virtual environment the various georeferenced orbital data in a “fly-over” fashion, highlighting a new interactive and immersive way to visualize geospatial data.

We focus the study on two centres of the two landing ellipses established for both missions (ExoMars, Mars2020) at the time this deliverable is written. All data provided by this deliverable (included within this GIS archive and integrated into the virtual environment) have been retrieved from publicly available and accessible repositories (e.g., PDS), except the DEM on Oxia Planum, which has been provided by the MarsSI team. These data are useful to the PlanMap effort to serve not only as basemaps for future enhanced mapping of the area, but also for the multiscale exploration and surface characterization in preparation for the landing and ground operations of these two future missions.

List of acronyms

Introduction

The deliverable 5.4, led by CNRS-LPG, is focused on the release of both a comprehensive GIS archive including orbital data and a VR application to visualize these data within an integrated virtual environment, to document future landing sites of the two major upcoming Mars missions ExoMars and Mars2020. These products are useful to the ongoing efforts of the planetary community to characterize the surface properties ahead of the actual landing of the rover, in preparation of the ground operations.

This project includes orbital data in the form of DEM, visible, infrared, and hyperspectral imagery, and geomorphological maps. These data were retrieved from various public repositories (e.g., Murray Lab’s or HiRISE project’s websites), georeferenced within the Mars 2000 spherical projection (Seidelmann et al., 2002), and then merged into a GIS software. All layers embedded within the GIS project (cf. Annex A) represent pre-processed and/or pre-mosaicked datasets (i.e., not in their raw format) to be readily usable for integration within the virtual environment rendered in the VR application.

This latter application (cf. Annex B), provided with this deliverable, allows the users to “fly over” the different landing sites with geospatial data rendered in real time, in order to visualize and contextualize at various scales the geological features of the terrains. This approach is particularly interesting to get an accurate representation of the actual terrain without deformations induced by traditional screens, and gives us the opportunity to explore the areas where the future rovers will land from up close and at ground level before they actually set a wheel on the ground.

Localization and Area of interest

Due to the increased interest on Mars exploration in recent years from different space agencies around the world, several robotic probes have been designed and/or sent during the 2020 launch window to study the red planet. Among them are the ESA/Roscosmos ExoMars and NASA’s Mars2020 missions, both aiming at landing an autonomous rover equipped with a battery of instruments to characterize the sedimentary series indicating past aqueous environmental conditions that could have been favourable to host life as we know it, at a time when it first appeared on Earth (~3.7-3.5 Ga). The selected sites for these missions are Oxia Planum for the first (e.g., Quantin-Nataf et al., 2021), and Jezero crater for the latter (e.g., Stack et al., 2020), both sites being located in a near-equatorial position (Fig. 1a).

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Figure 1: a) Global map of Mars (MOC imagery) with the localization of the two selected landing sites represented by a white box; b) Oxia Planum, the selected landing site for the future ExoMars mission. Red box highlights the working area considered by this deliverable; c) Jezero crater, the selected landing site for the forthcoming Mars2020 mission. Red box highlights the working area considered by this deliverable, including the western delta.

ExoMars and Oxia Planum

The joint ESA and Roscosmos ExoMars mission was designed as a three-part initiative, with an orbiter (Trace Gas Orbiter), a demonstrator lander (Schiaparelli) and a rover (Rosalind-Franklin), to investigate different aspects of the current and past environments on Mars. While TGO has been successfully launched and entered Martian orbit in October 2016, the launch of the rover has been delayed until the 2022 window of opportunity. This rover will be the first European autonomous probe to land on another planetary body, and its mission is to study the sedimentary series on Martian equatorial plains. It noteworthy embarks for the first time on such a probe a drill able to sample rock to a depth of about 2 meters.

Its selected landing site, Oxia Planum (Fig. 1b) is a large planar area located between Ares and Mawrth Valles in the northern hemisphere lowlands. This relatively flat area is thought to have hosted a large body of standing water at the mouth of a networked valley system (Quantin-Nataf et al., 2021). Specifically, large deposits of clay minerals as seen detected using orbital spectral data (e.g., Quantin-Nataf et al., 2021), which is particularly important for the investigation about the wetter and habitable past of Mars, as organic matter is more preferably retained and conserved within such clayish deposits (e.g., Farmer & DesMarais, 1999; Hays et al., 2017; Summons et al., 2011).

As part of this work, WP5 will focus on a ~135x95 km area of Oxia Planum represented as the red box on Figure 1b, which encompasses the provisional landing ellipse of the rover, and its regional vicinity.

Mars2020 and Jezero crater

After 8 successful years (and counting) in the Gale crater with Mars Science Laboratory, a new NASA-led mission has been launched on July 30^th, 2020 and is set to land on February 18^th, 2021. This mission, Mars 2020, and its rover named Perseverance, which is designed as an evolved successor to MSL Curiosity rover, will land in the Jezero crater, situated in the vicinity of the Isidis basin (Fig. 1c). This crater, much smaller than Gale (~50 km in diameter vs ~154 km) displays an impressive sedimentary record with two developed and well-preserved Gilbert delta systems, testimonials of a past active fluvial activity (e.g., Goudge et al., 2015, 2018; Noblet et al., 2020; Stack et al., 2020). These depositional settings are therefore of great interest in studying the past paleoenvironments of ancient and humid Mars, the presence of a delta meaning the sustained presence of liquid water (e.g., Mangold et al., 2020). Moreover, this specific area was also chosen among other potential landing sites using mineral compositions derived from orbital spectrometers. Indeed, the presence of clay minerals was a significant hint for aqueous processes in this area and potential conservation of organic matter (e.g., Goudge et al., 2015; Horgan et al., 2020). Most importantly, signatures of carbonates have been detected from orbit (Horgan et al., 2020). Carbonates are specifically important in our search for potential ancient Life on Mars, or at least habitable paleoconditions at the time of the deposition since carbonate deposits are most often associated with biotic activity on Earth, even in most remote periods (e.g., Archean).

As part of this work, WP5 will focus on a ~20x16 km area of Jezero represented as the red box on Figure 1c, which encompasses the provisional landing ellipse of the rover, the western deltaic deposits, and the mouth of the main input valley.

Softwares and formats used

Softwares

Both Open Source and proprietary softwares were used to process and merge data provided by this deliverable.

While most orbital data came in pre-processed and/or pre-mosaicked form, some of the data might have been corrected to ensure best co-registration or visualization. Those corrections were achieved using ISIS v.3 software for mosaicking and co-registration (provided by USGS), or IDL/ENVI v.5.4 for colorization of HiRISE visible data (see further; from Harris Geospatial Solutions).

Merging, georeferencing and digitalization were achieved using ArcGIS suite (from ESRI), and more precisely ArcMap v.10.8.1.

A videogame engine has been used to generate, encode and render the virtual environment, which is optimized for the Oculus VR systems (Rift S, Quest 1, Quest 2). The application has been compiled to run on Windows devices.

Other works including raster and/or vector modification, enhancing or annotation have been performed using Photoshop CS6 (v.13.0.1) and Illustrator CS5 (v.15.0.0) softwares from Adobe.

Formats

Data provided with this deliverable use several different file formats after their type (e.g., raster vs vector data). Main formats used for the data provided with this deliverable are listed in the Table 1. The accompanying formats generated by the GIS softwares (e.g., ArcMap) for projection and display of the different raster data in a given project (e.g., .ovr, .aux.xml or .tfw) are not mentioned here as they’re only dependant to the GIS solution used and are not part of the actual data. They are therefore not mentioned in the Annex A table either.

Table 1: List of specific file formats used in this deliverable.

Orbital Data and GIS archive

Most data merged into this GIS archive consist of product acquired by orbital embarked devices. Pre-processed and/or pre-mosaicked data are available as raster tiles (GeoTIFF, PNG), projected within the IAU Mars 2000 spherical projection (Seidelmann et al., 2002). Albeit the geomorphological maps directly apply to the description of the ground, they are herein categorized as orbital data, having been drawn to represent geomorphological facies originally defined from orbital imagery. Both the Oxia Planum and Jezero crater sites data are compiled within a dedicated GIS project, provided by this deliverable.

Oxia Planum

CTX

The Context (CTX) instrument is embarked on board the 2005 Mars Reconnaissance Orbiter spacecraft. This imager is built to observe the Martian surface to give context images for data acquired by other instruments aboard the space probe (e.g., HiRISE or CRISM), but also to conduct scientific investigation and long-term surveys of surficial changes (Malin et al., 2007; Bell et al., 2013). CTX have a resolution up to 5 m/pixel, allowing observation of metric-scale geomorphic features within a 30 m-wide swath of terrain. CTX is capable of taking stereo pairs to reconstruct the surface topography (using stereophotogrammetry; Malin et al., 2007).

Visible imagery data

This deliverable provides an extract of the CTX global mosaic (Dickson et al., 2018) generated and distributed by Caltech’s Murray Lab. This mosaic covers about 97 % of the entire planet, with a resolution of 5 m/pixel, including all data gathered by the instrument until December 2017. Figure 2 shows an extract of this global mosaic for the specified working area. This greyscale image allows the distinction of various metric-scale geomorphologic features, and notably several craters and inverted channels.

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Figure 2: High-resolution (up to 5 m/pixel) greyscale image of the working area from the CTX instrument.

Digital Elevation Model

This deliverable also provides a DEM of the Oxia Planum area generated using CTX stereo pairs. This DEM was provided by Matthieu Volat from the MarsSI team (https://marssi.univ-lyon1.fr/MarsSI/) at University of Lyon. This DEM shows elevation in meters (Fig. 3).

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Figure 3: Digital Elevation Model of the working area, obtained by stereophotogrammetry from CTX imagery data.

Morpho-stratigraphic/Textural Maps

Morpho-stratigraphic or textural map of the Martian surface allows to discriminate several types of geological features and/or (apparent) formations, based on observational criteria, such as roughness, brightness (albedo), presence of debris, dunes, etc. These observations lead to the characterization of “orbital facies” that can give insights about the origin and nature of the observed terrains (e.g., Grotzinger et al., 2014, for Gale crater). These orbital facies have to be completed by in situ observations whenever it is possible and notably when they are concerning rover missions providing ground truth. They are nevertheless an important product and are critical in preparing and planning ground operations once the rover has landed.

Regional map

As the ExoMars mission has yet to be launched, precise mapping of the Oxia Planum area is still underway, with result yet to be released (e.g., Hauber et al., 2020; Sefton-Nash et al., 2020). However, ESA has released a partial textural map of the landing site on its website in 2018 (updated in 2019, available at: https://exploration.esa.int/web/mars/-/60921-oxia-planum-texture-map). This map is based on a THEMIS thermal inertia basemap, and an extract covering the overall working area is provided with this deliverable (Fig. 4).

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Figure 4: Textural map of the Oxia Planum area around the provisional landing ellipse determined for the ExoMars mission (basemap: THEMIS thermal inertia image; credits: ESA).

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Figure 4 bis: Legend for the textural map.

Jezero crater

THEMIS

The THermal Emission Imaging System (THEMIS) instrument is embarked onboard the 2001 Mars Odyssey spacecraft. It allows investigating the surface mineralogy and surface properties of the Martian ground using a multi-spectral thermal-infrared imager in 9 wavelengths centred from 6.8 to 14.9 µm with a resolution of 100m/pixel, and a visible/near-infrared imager in 5 wavelengths centred from 0.42 to 0.86 µm with a resolution of 18m/pixel (Christensen et al., 2004).

This deliverable provides an extract of the pre-processed thermal inertia infrared imagery of the Jezero crater, centred on the western delta (Fig. 5), available on the ASU’s THEMIS team website (http://themis.asu.edu/). Thermal inertia is expressed in J m^-2 K^-1 s^-1/2.

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Figure 5: Thermal inertia map of the working area from the THEMIS instrument.

CRISM

The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument is embarked on board the 2005 Mars Reconnaissance Orbiter spacecraft. Its primary objective is to map the surface crustal mineralogy and investigate the potential past presence of aqueous activity by discriminating the presence of hydrated minerals (Murchie et al., 2007). Its multispectral imager is able to collect up to 72 wavelengths ranging from ultraviolet (362 nm) to mid-wave infrared (3920 nm).

Several sets of spectral parameters were used by Horgan et al. (2020) to compute RGB composites in order to study and evaluate the mineralogical differences in the delta area, notably to discriminate the carbonate units and related deposits, a major goal of the Mars2020 mission in the Jezero crater (e.g., Horgan et al., 2020; Stack et al., 2020). This deliverable provides extracts of the pre-processed hyper-spectral imagery of the Jezero crater western delta by Horgan et al. (2020). Before any further interpretation, the users are invited to refer to Horgan et al. (2020) and Viviano-Beck et al. (2014) and the references therein to understand the signification and potential limits of these hyper-spectral images (e.g., treatment, resolution, threshold, etc.). Five different layers are proposed in the GIS, corresponding to composites whose parameters are indicated in Table 2. All layers have been pan-sharpened with CTX basemap (except for the fan-focused mafic composite, pan-sharpened with HiRISE basemap) to enhance contrast and improve readability of the surface morphology.

Table 2: List of pre-processed hyper-spectral imagery products from CRISM instrument after Horgan et al. (2020), using spectral parameters defined by Viviano-Beck et al. (2014)

False colours

The False colours layer is a RGB composite, providing a synthetic view of the mineralogical variations in the area, allowing correlations of compositions and geomorphic landforms at the surface (Fig. 6).

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Figure 6: False colours map of the working area from the CRISM instrument, showing mineralogical variations. Red: olivine. Green to blue: carbonates. Purple: low-calcium pyroxene. Brown: mafic floor (basemap: CTX).

Carbonates

The Carbonates layer is a RGB composite allowing to observe the variability within the carbonate units (Fig. 7).

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Figure 7: Carbonates map of the working area from the CRISM instrument, showing variations among the carbonate units. Red: olivine. Cyan/blue: strong carbonates, weaker olivine. Yellow/white: strong carbonates and strong olivine. Green: relatively olivine-poor with other Fe-bearing phases (e.g., clays/ carbonates) (basemap: CTX).

Hydration layer

The Hydration layer is a RGB composite allowing to evaluate the hydration present within carbonate and/or clay minerals (Fig. 8).

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Figure 8: Hydration map of the working area from the CRISM instrument, showing hydration variations with clays and carbonates. White: hydration with carbonates. Magenta: weak or no hydration with carbonates. Green: hydration with weak carbonates or other phases like Al-clays and silica. Yellow/orange: Fe/Mg-clays (basemap: CTX).

Phyllosilicates layer

The Phyllosilicates layer is a RBG composite allowing to discriminate varying phyllosilicate compositions (Fig. 9).

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Figure 9: Phyllosilicate map of the working area from the CRISM instrument, showing mineralogical variations among alteration minerals (Al/SI vs Fe/Mg). Red/Yellow: Fe/Mg-smectites or carbonates. Green: Al-clays. Cyan: silica or Al-clays. Blue: opal or hydrated silica (basemap: CTX).

Mafic minerals layer

The Mafic minerals layers are RGB composites allowing to observe the compositional variations of the primary mafic minerals in the whole studied area (Fig. 10) or at a more focused level on the delta only (Fig. 11).

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Figure 10: Mafic minerals map of the working area from the CRISM instrument, showing compositional variations of the primary mafic minerals. Red: olivine and mafic component of carbonates. Green: Low- calcium pyroxene. Blue: High-calcium pyroxene (basemap: CTX).

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Figure 11: Mafic minerals map focused on the fan delta area from the CRISM instrument, showing compositional variations of the primary mafic minerals. Red: olivine and mafic component of carbonates. Green: Low- calcium pyroxene. Blue: High-calcium pyroxene (basemap: HiRISE).

MOLA

The Mars Orbiter Laser Altimeter (MOLA) instrument is embarked on board the 1996 Mars Global Surveyor. This instrument was the first to provide information about the global altimetry and surface roughness of Mars, with a resolution up to 100 m/pixel (Smith et al., 2001). These legacy data, available in their latest 2003 revision on the PDS (http://pds-geosciences.wustl.edu/missions/mgs/megdr.html) are not resolved enough for the PlanMap effort (~900 m/pixel in this area). Anyway, this deliverable provides an extract of the MOLA global altimetry cover (Fig. 12) as comparison and calibration reference for other altimetric data derived from indirect methods (e.g., HiRISE photogrammetric DEM), with elevations in meters.

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Figure 12: Digital Elevation Model of the working area (with horizontal resolution of ~900 m/px), obtained by laser altimetry from the MOLA instrument.

HRSC

The High Resolution Stereo Camera (HRSC) is embarked on board the 2003 Mars Express spacecraft. This imager was built to obtain high resolution colour stereo images of the Martian surface (Neukum & Jaumann, 2004). HRSC provides images with a resolution of 10 m/pixel, that are used to observe decametric-scale geomorphologic features on the surface, but also to produce stereophotogrammetric DEMs. While the HRSC elevation data are not resolved enough compared to other products (CTX and HiRISE, see further), this deliverable provides an extract of the HRSC DEM archive (https://pds-geosciences.wustl.edu/missions/mars_express/hrsc.htm) of the working area for comparison and calibration purposes (Fig. 13), with elevations in meters.

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Figure 13: Digital Elevation Model of the working area (with horizontal resolution of ~50 m/px), obtained stereophotogrammetry from HRSC imagery data.

CTX

The Context (CTX) instrument is embarked on board the 2005 Mars Reconnaissance Orbiter spacecraft. This imager is built to observe the Martian surface to give context images for data acquired by other instruments abord the probe (e.g., HiRISE or CRISM), but also to conduct scientific investigation and long-term surveys of surficial changes (Malin et al., 2007; Bell et al., 2013). CTX have a resolution up to 5 m/pixel, allowing to observe metric-scale geomorphic features within a 30 m-wide swath of terrain. CTX is capable of taking stereo pairs to reconstruct the surface topography (using stereophotogrammetry; Malin et al., 2007).

Visible imagery data

This deliverable provides an extract of the CTX global mosaic (Dickson et al., 2018) generated and distributed by Caltech’s Murray Lab. This mosaic covers about 97 % of the entire planet, with a resolution of 5 m/pixel, including all data gathered by the instrument until December 2017. Figure 14 shows an extract of this global mosaic for the specified working area. This greyscale image allows the distinction of various metric-scale geomorphologic features, and notably the different lobes and channels observed on the delta.

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Figure 14: High-resolution (up to 5 m/pixel) greyscale image of the working area from the CTX instrument

Digital Elevation Model

This deliverable also provides an extract of the CTX DEM computed by stereophotogrammetry from CTX orthoimages. This DEM shows variations in elevation in meters (Fig. 15). This DEM offers a complete coverage of the study area with sufficient vertical and horizontal resolutions to characterize the geomorphic landforms present at the surface.

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Figure 15: Digital Elevation Model of the working area (with horizontal resolution of ~10 m/px), obtained by stereophotogrammetry from CTX imagery data.

HiRISE

The High-Resolution Imaging Science Experiment (HiRISE) instrument is embarked on board the 2005 Mars Reconnaissance Orbiter spacecraft. As the most resolved imager to date orbiting Mars, its main scope is to capture and deliver ultra-high definition images of the Martian surface, with a resolution up to 25 cm/pixel (McEwen et al., 2007). Colour information can be retrieved from the Red, Blue-Green and NIR channels to produced full colour images of the red planet. Moreover, HiRISE is capable of taking stereo pairs used to reconstruct the surface topography (using stereophotogrammetry), with a horizontal gridding of 1 m/pixel and a vertical accuracy usually around the tens of cm (McEwen et al., 2007).

Visible imagery data

This deliverable provides an extract a HiRISE orthoimage computed and provided by Caltech’s Murray Lab and available online (http://murray-lab.caltech.edu/Mars2020/). This greyscale image (Fig. 16) displays the highest resolution available for this area (25 cm/pixel), allowing distinction of metric-scale geological features on the Martian surface. It is currently the most advanced imagery product available and serves as a base for morpho-stratigraphic observations and interpretations (e.g., Noblet et al., 2020, see Morpho-stratigraphic maps). This basemap does not cover the entire extent of the study area, hence we rely on CTX basemap for a full frame coverage. Nonetheless, the HiRISE product covers the delta and the inlet valley’s canyon across the crater rim. 

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Figure 16: High-resolution (up to 25 cm/pixel) greyscale image of the working area from the HiRISE instrument

Digital Elevation Model

This deliverable also provides an extract of the HiRISE DEM, also from the Murray Lab (same URL as for the orthoimage). This DEM shows variations in elevation in meters (Fig. 17). Again, the HiRISE DEM does not offer a complete coverage, so the CTX DEM can be used as a surrogate for contextual observations. Nonetheless, both the delta and the inlet valley’s canyon across the crater rim are represented by this product.

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Figure 17: Digital Elevation Model of the working area (with horizontal resolution of 1 m/px), obtained by photogrammetry from HiRISE imagery data.

Morpho-stratigraphic Maps

Regional crater map

A regional morpho-stratigraphic map of the Jezero crater has been constructed by Goudge et al. (2015), largely based on CTX basemap. This general map allows to distinguish several types of terrains inside the Jezero crater basin, and to noteworthy identify the two deltas present in the north and western part of the basin, the inlet valleys and the outlet valley. These geomorphic features have been strong advocates for the selection of this landing site for the Mars2020 mission to try and learn more about the wetter past climates and environments on Mars. This deliverable provides an extract of this regional map, centred on the delta (Fig. 18); The map features 11 types of orbital facies whose specific parameters are detailed by Goudge et al. (2015).

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Figure 18: Regional morpho-stratigraphic map (after Goudge et al., 2015) of the working area, displaying 11 different “orbital facies”, and notably the western inlet valley and delta of Jezero crater (basemap: CTX).

Localized delta-centred map

Aside from the regional-scale map from Goudge et al. (2015), Noblet et al. (2020) proposed a more detailed (1:10 000) map of the delta and its immediate surroundings. This map (Fig. 19) shows a variety of surface textures, structures, and morphologies with great detail. It is largely based on HiRISE basemap.

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Figure 19: Morpho-stratigraphic map of the Jezero crater western delta, from Noblet et al. (2020) (basemap: CTX+HiRISE).

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Figure 19 bis: Legend for the morpho-stratigraphic map.

Landing ellipse

The planned landing ellipse for the Mars2020 rover Perseverance (due to land on February 18^th, 2021) has been drawn as a shapefile after the reference Photojournal image PIA23511 (https://photojournal.jpl.nasa.gov/catalog/PIA23511). It represents the landing ellipse as of November 2019 (Fig. 20).

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Figure 20: Position of the landing ellipse planned for the Mars2020 rover Perseverance, on a CTX basemap.

Exploration of the future landing sites in VR

Creating a Virtual Environment

VR can be used in a variety of ways in Planetary Science, to contextualize, visualize or characterize large sets of 3D data gathered by the robotic probes sent to explore our solar system. To that extent, the study of orbital data from future landing sites in VR provides a wealth of information that could be used to help prepare ground operations when the mission finally lands.

We provide with this deliverable an integrated VR application that features both Oxia Planum and Jezero crater future landing sites, reconstructed within a virtual environment, allowing to visualize at various scale and with a high degree of liberty several layers of geological information.

Due to the large amount of geospatial data and the need for a seamless integration in VR, we are using a versatile videogame engine (e.g., Mat et al., 2014) to compile and render the virtual environment. That way, we are able to deal with the different layers of heavy high-resolution graphic data (e.g., orthoimages), in the same way a GIS software would do. Doing this, we also ensure a maximum compatibility with publicly available VR hardware (headsets, controllers, gaming-rated computers). This VR application has been developed using Oculus devices (Rift S, Quest 1/2). The application should nonetheless also work with HTC devices (Vive/Vive Pro) but does not support the in-app display of proper HTC controllers.

Orbital data and models

Both Oxia Planum and Jezero crater landing sites have been reconstructed in the virtual environment with orbital data that are used to:

• Create the 3D terrains from raster DEMs.
• Create a “GIS-like” multi-layers display, allowing the users to easily switch between the layers to visualize the relevant information.

Contrary to the VR application provided with deliverable 5.3 (Caravaca et al., 2020), no 3D meshes are used as intermediate between the raw data (see D.5.1 and D.5.2, Caravaca et al., 2019a; 2019b) and the VR application, since the rendering engine is able to generate by itself the geographic 3D terrain. For visualization purposes, the greyscale basemaps have been artificially coloured according to colour information from previous spectral observations to match the actual coloration of the Martian ground, in order to improve the immersion within the virtual environment and realism. All the data used for the generation of the virtual environment are provided as part of the GIS projects with this deliverable.

Multi-scale exploration of the virtual environment

One of the most acclaimed breakthroughs of the VR is the ability to experience the virtual environment as if the users were actually there. This feature is very useful in Geosciences, and particularly to the PlanMap effort in that we are able to explore digitally reconstructed areas that are situated several millions of km away, without the necessity of being there in person. This capacity is even more interesting as we present in this deliverable the landing sites for future/forthcoming robotic missions. Using VR, the users have therefore the opportunity to observe and characterize geological features that could have not been readily appreciable by other means (e.g., 2D “flat” panorama images), in preparation for landings and future ground operations.

Navigation within the virtual environment

Navigation within the virtual environment relies on a quite simple “fly-over” system. The users have  the capacity of flying anywhere above the reconstructed terrains. Such control is achieved using the VR controllers (Fig. 21), with lateral triggers allowing to move up or down, and upper joysticks enabling horizontal displacement on the left controller, and rotation on the roll-axis on the right controller. That way, the users can adjust in real time their position in 3D space to get the best point of view.

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Figure 21: In-app illustration of the different controls (using Oculus VR device) allowing the users to move around the reconstructed terrain in the virtual environment, along the 3D six axis.

Navigation in-between the Oxia Planum and Jezero crater scenes, and within the displayed menu to switch the displayed layers is also very simple. The users are only required to move either controller toward the hovering menu buttons. As the controller aligns with the button, a “laser beam” will appear for precise pointing. Selection of the wanted option is done by pulling the trigger on the same controller (Fig. 22). A call-back to these functions is also displayed on the user interface with the possibility to disable this display by pressing “A” button on the Oculus controller (function not supported on HTC devices; Fig. 22).

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Figure 22: In-app illustration of the selection menu for the layers available on the Oxia Planum landing site scene. The displayed VR user is currently selecting CTX layer to replace the active geomorphological map (from ESA) layer.

Oxia Planum landing site

The VR application provided with this deliverable allows the users to visualize the Oxia Planum future landing site, to observe the various geomorphic features (e.g., craters, inverted channels; Fig. 23). In this virtual environment, the terrain is generated from the CTX DEM. Available layers for display are the ESA’s geomorphological map (Fig. 22; legend is displayed onscreen) and the colorized CTX mosaic (Fig. 23).

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Figure 23: In-app view of the Oxia Planum future landing site. The active layer displayed in this screen capture is the coloured CTX orthoimage basemap, draped over the CTX DEM.

Jezero crater landing site

The VR application provided with this deliverable allows the users to visualize the Jezero crater future landing site, to observe the various geomorphic features and notably the western delta (Fig. 24). In this virtual environment, a selection of relevant layers from the GIS archive has been integrated within the virtual environment (Fig. 24a). The terrains are generated either from the CTX DEM (e.g., Fig. 24b) or from the HiRISE DEM (e.g., Fig. 24c). Coloured CTX and HiRISE basemaps are available (Figs. 24b and 24c, respectively), as well as CRISM False colours and Mafic spectral maps (Figs. 24d and 24e; legend displayed onscreen), and the morpho-stratigraphic map from Noblet et al. (2020; Fig. 24f; legend displayed onscreen). The figure 25 shows a close-up view toward the delta foot from a low altitude (nearly ground-based) perspective of a VR user and lets appreciate the morphologies Perseverance is set to encounter.

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Figure 24: In-app view of the Jezero crater future landing site, with the distinctive delta; a) general view of the reconstructed area and in-app selection menu for the different available layers; b) Coloured CTX basemap draped over CTX DEM; c) HiRISE coloured basemap draped over HiRISE DEM; d) CRISM False colour map (from Horgan et al., 2020) draped over CTX DEM; e) CRISM Mafic map (from Horgan et al., 2020) draped over CTX DEM; f) Morpho-stratigraphic map (from Noblet et al., 2020) draped over CTX DEM.

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Figure 25: In-app view of the Jezero crater landing site toward the western delta foot, as seen from a low altitude perspective. Oculus Touch controllers of the user can also be seen. 

Kimberley outcrop, Gale crater

The VR application provided with this deliverable also provides a virtual environment reproducing the Kimberley outcrop along the traverse of the Curiosity rover in Gale crater (Fig. 26). This scene was generated using 3D data provided by deliverable 5.2 (Caravaca et al., 2019b), and features the high-resolution DOM of the entire outcrop and the micro-DOM of the Windjana drill. Two layers are available for this environment: the morpho-stratigraphic map from Grotzinger et al. (2014), and a HiRISE orthoimage. The embedded rover mesh gives scale to appreciate real sizes of the geologic objects.

 Image Added

Figure 26: In-app view of the Kimberley outcrop in Gale crater. MSL mesh is used to set the scale.

Acknowledgements

We thank the MarsSI team and Cathy Quantin-Nataf of the LGL-TPE at the University Claude Bernard of Lyon (France) for providing us with the CTX DEM data for Oxia Planum.

References

Bell III, J. F., Malin, M. C., Caplinger, M. A., Fahle, J., Wolff, M. J., Cantor, B. A., 2013. Calibration and performance of the Mars Reconnaissance Orbiter Context camera (CTX). Mars 8, 1-14. DOI: 10.1555/mars.2013.0001

Caravaca, G., Le Mouélic, S., Mangold, N., 2019a. Deliverable 5.1: Merged products (in GIS and as maps) of orbital and in situ data of Gale crater. URL: https://wiki.planmap.eu/display/public/D5.1-public.

Caravaca, G., Le Mouélic, S., Mangold, N., 2019b. Deliverable 5.2: 3D products of the merged GIS and maps of Gale crater. URL: https://wiki.planmap.eu/display/public/D5.2-public.

Caravaca, G., Le Mouélic, S., Mangold, N., 2020. Deliverable 5.3: 3D geomodels in Virtual Reality. URL: https://wiki.planmap.eu/display/public/D5.3-public.

Christensen, P. R., Jakosky, B. R., Kieffer, H. H., Malin, M. C., McSween, H.Y. Jr., Nealson, K., et al., 2004. The Thermal Emission Imaging System (THEMIS) for the Mars 2001 Odyssey Mission. Space Science Reviews 110, 85-130. DOI: 10.1023/B:SPAC.0000021008.16305.94

Dickson, J. L., Kerber, L. A., Fassett, C. I., Ehlmann, B. L., 2018. A global, blended CTX mosaic of Mars with vectorized seam mapping: a new mosaicking pipeline using principles of non-destructive image editing. LPSC IL, Abstract #2480.

Farmer, J. D. & DesMarais, J. D., 1999. Exploring for a record of ancient Martian Life. Journal of Geophysical Research, 104(E11), 26,977-26,995. DOI: 10.1029/1998JE000540

Goudge, T.A., Mustard, J. F., Head, J. W., Fassett, C. I., Wiseman, S. M., 2015. Asessing the mineralogy of the watershed and fan deposits of the Jezero crater paleolake system, Mars. Journal of Geophysical Research: Planets 120(4), 775-808. DOI: 10.1002/2014JE004782

Goudge, T. A., Mohring, D., Cardenas, B. T., Hughes, C. M., Fassett, C. I., 2018. Stratigraphy and paleohydrology of delta channel deposits, Jezero crater, Mars. Icarus 301, 58-75. DOI: 10.1016/j.icarus.2017.09.034

Grotzinger, J. P. , Sumner, D. Y., Kah, L. C., Stack, K., Gupta, S., Edgar, L., et al., 2014. A habitable fluvio-lacustrine environment at Yellowknife Bay, Gale crater, Mars. Science 343(6169), 1242777

Hauber, H., Adeli, S., Tirsch, D., Nass, A., Acktories, S., Steffens, S., 2020. Regional geologic mapping of the Oxia Planum landing site for the ExoMars mission. EPSC Abstracts 14, EPSC2020-1100. DOI: 10.5194/epsc2020-1100

Hays, L. E., Graham, H .V., DesMarais, D. J., Hausrath, E. M., Horgan, B., McCollom, T. M., et al., 2017. Biosognature preservation and detection in Mars analog environments. Astrobiology 17(4), 363-400. DOI: 10.1089/ast.2016.1627

Horgan, B. H.  N., Anderson, R. A., Dromart, G., Amador, E. S., Rice, M. S., 2020. The mineral diversity of Jezero crater: Evidence for possible lacustrine carbonates on Mars. Icarus 339, 113526. DOI: 10.1016/j.icarus.2019.113526

Malin, M. C., Bell III, J. F., Cantor, B. A., Caplinger, M. A., Calvin, W. M., Clancy, R. T., et al., 2007. Context camera investigation on board the Mars Reconnaissance Orbiter. Journal of Geophysical Research 112. DOI: 10.1029/2006JE002808

Mangold, N., Dromart, G., Ansan, V., Salese, F., Kleinhas, M. G., Massé, M., et al., 2020. Fluvial régimes, morphometry, and age of Jezero crater paleolake inlet valleys and their exobiological significance for the 2020 rover mission landing site. Astrobiology 20(8). DOI: 10.1089/ast.2019.2132

Mat, R. C., Shariff, A. R. M., Zulkifli, A. N., Rahim, M. S. M., Mahayudin, M. H., 2014. Using game engine for 3D terrain visualisation of GIS data: A review. In IOP Conference Series: Earth and Environmental Science 20, 012037. URL: https://iopscience.iop.org/article/10.1088/1755-1315/20/1/012037/pdf

McEwen, A. S., Eliason, E. M., Bergstrom, J. W., Bridges, N. T., Hansen, C. J., Delamere, W. A., et al., 2007. Mars reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE). Journal of Geophysical Research: Planets 112(E05S02). DOI: 10.1029/2005JE002605.

Murchie, S., Arvidson, R., Bedini, P., Beisser, K., Bibring, J.-P., Bishop, J., et al., 2007. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on Mars Reconnaissance Orbiter (MRO). Journal of Geophysical Research 112(E05S03). DOI: 10.1029/2006JE002682.

Neukum, G. & Jaumann, R., 2004. HRSC: The high resolution stereo camera of Mars Express. In Mars Express: The Scientific Payload 1240, 17-35.

Noblet, A., Caravaca, G., Le Mouélic, S., Massé, M., Mangold, N., 2020. Morpho-stratigraphic map of Jezero crater landing area. Dataset, Zenodo. DOI: 10.5281/zenodo.3762957

Quantin-Nataf, C., Carter, J., Mandon, L., Thollot, P., Balme, M., Volat, M., et al., 2021. Oxia Planum : the landing site for the ExoMars « Rosaling Franklin” rover mission: Geological context and prelanding interpretation. Astrobiology 21(3). DOI: 10.1089/ast.2019.2191

Sefton-Nash, E., Balme, M., Quantin-Nataf, C., Fawdon, P., Volat, M., Hauber, H., et al., 2020. HiRISE-scale characterization of the Oxia Planum landing site for the ExoMars 2022 mission. EPSC Abstracts 14, EPSC2020-978. DOI: 10.5194/epsc2020-978

Seidelmann, P. K., Abalakin, V. K., Bursa, M., Davies, M. .E, de Bergh, C., Lieske, J. H., et al., 2002. Report of the IAU/IAG working group on cartographic coordinates and rotational elements of the planets and satellites: 2000. Celest Mech Dyn Astron 82(1):83–111. DOI: 10.1023/A:1013939327465

Smith, D. E., Zuber, M. T., Frey, H. V., Garvin, J. B., Head, J. W., Muhleman, D. O., et al., 2001. Mars Orbiter Laser Altimeter: Experiment summary after the first year of global mapping of Mars. Journal of Geophysical Research 106(E10), 23,689-23,722. DOI: 10.1029/2000JE001364

Stack, K. M., Williams, N. R., Callef III, F., Sun, V. Z., Williford, K. H., Farley, K. A., et al., 2020. Photogeological maps of the Perseverance rover field site in Jezero crater constructed by the Mars 2020  Science Team. Space Science Reviews 216(127). DOI: 10.1007/s11214-020-00739-x

Summons, R.E ., Amend, J. P., Bish, D., Buick, R., Coby, G. D., DesMarais, D. J., et al., 2011. Preservation of Martian organic and environmental records: final report of the Mars Biosignature Working Group. Astrobiology 11(2), 157-181. DOI: 10.1089/ast.2010.0506

Viviano-Beck, C. E., Seelos, F. P., Murchie, S. L., Kahn, E. G., Seelos, K. D., Taylor, H. W.,et al., 2014. Revised CRISM spectral parameters and summary products based on the currently detected mineral diversity on Mars. Journal of Geophysical Research Planets 119 (6), 1403–1431.DOI: 10.1002/2014JE004627

Annex A: List of source data and layers of the provided GIS projects

Table A1 lists all files provided by this deliverable for the Oxia Planum landing site GIS project (“5-4_GIS_project_Oxia-Planum – Geopackage.mxd”). The table also stipulates their address relative to the “Home” folder of the GIS project and which layer (.lyr file) they are called under to load them with their specific and correct symbology when needed (e.g., colours for maps, or coloured scale for stretched graphics).

Table A1: List of files provided with this deliverable and embedded into the Oxia Planum landing site GIS project, with the layers they are associated with.

Table A2 lists all files provided by this deliverable for the Jezero crater landing site GIS project (“5-4_GIS_project_Jezero_delta – Geopackage.mxd”). The table also stipulates their address relative to the “Home” folder of the GIS project and which layer (.lyr file) they are called under to load them with their specific and correct symbology when needed (e.g., colours for maps, or coloured scale for stretched graphics).

Table A2: List of files provided with this deliverable and embedded into the Jezero crater landing site GIS project, with the layers they are associated with.

Annex B: List of VR application files provided by this deliverable

Table B1 lists all application files provided by this deliverable:

Table B1: List of the files provided with this deliverable for the VR application.