Digging deep for ice in Isidis Planitia—New constraints on subsurface volatile concentrations from thermal modeling

The Isidis Planitia region on Mars usually is regarded as a comparably attractive site for landing missions based on engineering constraints such as elevation and smooth regional topography. The Mars Express landed element Beagle 2 was deployed to this area, and the southern margin of the basin was selected as one of the backup landing sites for the NASA Mars Exploration Rovers.Especially in the context of the Beagle 2 mission, Isidis Planitia has been discussed as a place which might have experienced a volatile-rich history with associated potential for biological activity [e.g. Bridges et al., 2003. Selection of the landing site in Isidis Planitia of Mars Probe Beagle 2. J. Geophys. Res. 108(E1), 5001, doi: 10.1029/2001JE001820]. However the measurements of by the GRS instrument on Mars Odyssey indicate a maximum inferred water abundance of only 3 wt% in the upper few meters of the surface [Feldman et al., 2004. Global distribution of near-surface hydrogen on Mars. J. Geophys. Res. 109, E09006, doi: 10.1029/2003JE002160]. Based on these measurements this area seems to be one of the driest spots in the equatorial region of Mars.To support future landing site selections we took a more detailed look at the minimum burial depth of stable ice deposits in this area, focusing as an example on the planned Beagle 2 landing site. We are especially interested in the likelihood of ground ice deposits within the range of proposed subsurface sampling tools as drills or ‘mole’-like devices [Richter et al., 2002. Development and testing of subsurface sampling devices for the Beagle 2 Lander. Planet. Space Sci. 50, 903-913] given reasonable physical constraints for the surface and near surface material.For a mission like ExoMars [Kminek, G., Vago, J.L., 2005. The Aurora Exploration Program—The ExoMars Mission. In: Proceedings of the 35th Lunar and Planetary Science Conference, abstract no. 1111, 15-19 March 2004, League City, TX] with a focus on finding traces of fossil life the area might be of potential interest, because these traces would be better conserved in the dry soil. Modeling and measurement indicate that Isidis Planitia is indeed a dry place and any hypothetical ground ice deposits in this region are out of range of currently proposed sampling devices.     

Characterization of the particle radiation environment at three potential landing sites on Mars using ESA’s MEREM models

The ‘Mars Energetic Radiation Environment Models’ (dMEREM and eMEREM) recently developed for the European Space Agency are herein used to estimate, for the first time, background Galactic Cosmic Ray (GCR) radiation and flare related solar energetic particle (SEP) events at three candidate martian landing sites under conditions where particle arrival occurred at solar minimum (December, 2006) and solar maximum (April, 2002) during Solar Cycle 23. The three landing sites were selected on the basis that they are characterized by significantly different hydrological conditions and soil compositions. Energetic particle data sets recorded on orbit at Mars at the relevant times were incomplete because of gaps in the measurements due to operational constraints. Thus, in the present study, comprehensive near-Earth particle measurements made aboard the GOES spacecraft were used as proxies to estimate the overall particle doses at each perspective landing site, assuming in each case that the fluxes fell off as 1/r² (where r is the helio-radial distance) and that good magnetic connectivity always prevailed. The results indicate that the particle radiation environment on Mars can vary according to the epoch concerned and the landing site selected. Particle estimations obtained using MEREM are in reasonable agreement, given the inherent differences between the models, with the related NASA Heavy Ion–Nucleon Transport Code for Space Radiation/HZETRN. Both sets of results indicated that, for short (30 days) stays, the atmosphere of Mars, in the cases of the SEPs studied and the then prevailing background galactic cosmic radiation, provided sufficient shielding at the planetary surface to maintain annual skin and blood forming organ/BFO dose levels below currently accepted ionizing radiation exposure limits. The threat of occurrence of a hard spectrum SEP during Cruise-Phase transfers to/from Mars over 400 days, combined with the associated cumulative effect of prolonged GCR exposure, poses an as yet unsolved hazard to prospective onboard personnel.     

Landing Area Selection Based on Closed Environment Avoidance from a Single Image During Optical Coarse Hazard Detection

The success of a landed space exploration depends largely on the final landing site, and the most important factor of landing site selection is the safety of lander, so, hazard detection and avoidance are crucial during asteroid landing. Many approaches have been proposed at present, most of them just detect hazard and select an area that is free of hazard threaten, however, in some cases, the selected site should not be the places that located in closed environment, such as the inner of crater. To tackle the issue, an approach for selecting landing site with closed environment avoidance based on a single image during optical coarse hazard detection was proposed in this paper, the approach was designed under the scheme of Chang’e-3’s landing process. The approach begins with hazard detection based on a proposed binary method. And then, for searching the candidate circular landing areas, the skeletons of areas with no hazard are taken into account, and then, control constraints are considered to select the landing areas that are accessible by the lander. Finally, the final selected circular landing area are chosen by a proposed scoring method, this method combines the factors of circular areas, including radius, the connection among circular areas, circular area’s texture and the cluster relation between circular area’s center and all the hazard. At last, serious of experiments would be conducted to test the performance of the proposed approach.     

Determining the local abundance of Martian methane and its’ 13C/12C and D/H isotopic ratios for comparison with related gas and soil analysis on the 2011 Mars Science Laboratory (MSL) mission

Understanding the origin of Martian methane will require numerous complementary measurements from both in situ and remote sensing investigations and laboratory work to correlate planetary surface geophysics with atmospheric dynamics and chemistry. Three instruments (Quadrupole Mass Spectrometer (QMS), Gas Chromatograph (GC) and Tunable Laser Spectrometer (TLS)) with sophisticated sample handling and processing capability make up the Sample Analysis at Mars (SAM) analytical chemistry suite on NASA’s 2011 Mars Science Laboratory (MSL) Mission. Leveraging off the SAM sample and gas processing capability that includes methane enrichment, TLS has unprecedented sensitivity for measuring absolute methane (parts-per-trillion), water, and carbon dioxide abundances in both the Martian atmosphere and evolved from heated soil samples. In concert with a wide variety of associated trace gases (e.g. SO₂, H₂S, NH₃, higher hydrocarbons, organics, etc.) and other isotope ratios measured by SAM, TLS will focus on determining the absolute abundances of methane, water and carbon dioxide, and their isotope ratios: ¹³C/¹²C and D/H in methane; ¹³C/¹²C and ¹⁸O/¹⁷O/¹⁶O in carbon dioxide; and ¹⁸O/¹⁷O/¹⁶O and D/H in water. Measurements near the MSL landing site will be correlated with satellite (Mars Express, Mars 2016) and ground-based observations.     

The EURONEAR Lightcurve Survey of Near Earth Asteroids 2017–2020

Earth, Moon, and Planets - The Perseverance rover (Mars 2020) mission, the first step in NASA’s Mars Sample Return (MSR) program, will select samples for caching based on their potential to...     

Orbital identification of clays and carbonates in Gusev crater

Gusev crater was selected as the landing site of one of the two NASA Mars Exploration Rovers because water once could have ponded within the crater and partly filled it with sediments as suggested by the presence of a feeder channel and the fluvial-lacustrine morphology of the in-filling. However, the paucity of mineralogical evidence for fluvial-lacustrine activity revealed by the Spirit rover has remained a puzzle for years. Using orbital, near-infrared imaging spectroscopy, we report the detection of phyllosilicates and carbonates within and around the landing site of Spirit on the floor of Gusev crater. Placed in their geomorphological context, these minerals shed new light on the aqueous history of this crater, and offer a framework for the Spirit in situ measurements.     

Constraints on the origin and evolution of the layered mound in Gale Crater, Mars using Mars Reconnaissance Orbiter data

Gale Crater contains a 5.2 km-high central mound of layered material that is largely sedimentary in origin and has been considered as a potential landing site for both the MER (Mars Exploration Rover) and MSL (Mars Science Laboratory) missions. We have analyzed recent data from Mars Reconnaissance Orbiter to help unravel the complex geologic history evidenced by these layered deposits and other landforms in the crater. Results from imaging data from the High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) confirm geomorphic evidence for fluvial activity and may indicate an early lacustrine phase. Analysis of spectral data from the CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) instrument shows clay-bearing units interstratified with sulfate-bearing strata in the lower member of the layered mound, again indicative of aqueous activity. The formation age of the layered mound, derived from crater counts and superposition relationships, is ∼3.6-3.8 Ga and straddles the Noachian-Hesperian time-stratigraphic boundary. Thus Gale provides a unique opportunity to investigate global environmental change on Mars during a period of transition from an environment that favored phyllosilicate deposition to a later one that was dominated by sulfate formation.     

Slope morphology of hills at the Mars Pathfinder landing site

The study of hillslopes is a primary element of geomorphology and has successfully been used in many terrestrial arenas. In this study we take advantage of High Resolution Imaging Science Experiment (HiRISE) imagery as well as Mars Orbiter Camera (MOC) derived DEMs of the Pathfinder landing site to study regional hillslopes at resolutions many times greater than previously available and compare them with Mars Pathfinder lander images. This site was thought to be modified by massive flooding 1.8-3.5 byr ago and although evidence of flood activity was not obvious at the finer scale of this study, possible lee deposits and terracing were seen in some of the features. Evidence of post flood processes of ice related creep, aeolian and dry mass wasting were observed at the site and have likely obscured flood related morphology present in these features. Regional slopes were found to vary with aspect and suggest processes intensities operating at different orientations, possibly related to the prevailing wind direction, as well as the origin of the ancient flood event.     

Landing on Venus: Past and future

We briefly describe the history of landings on Venus, the acquired geochemical data and their potential petrologic interpretations. We suggest a new approach to Venus landing site selection that would avoid the potential contamination by ejecta from upwind impact craters. We also describe candidate units to be sampled in both in situ measurement and sample return missions. For the in situ measurements, the “true” tessera terrain (tt) material is considered as the highest priority goal with the second priority given to transitional tessera terrain (ttt), shield plains (psh) and lobate plains (pl) materials. For the sample return mission, the material of regional plains with wrinkle ridges (pwr) is considered as the highest priority goal with the second priority given to tessera terrain (tt) material. Combining the desire to study materials of specific geologic units with the problem of avoiding potential contamination by ejecta from upwind impact craters, we have suggested several candidate landing sites for each of the geologic units. Although spacecraft ballistics and other constraints of specific mission profiles (VEP or others) may lead to the selection of different candidate sites, we believe that the approaches outlined in this paper can be helpful approach in optimizing mission science return.     

Assessment of a 2016 mission concept: The search for trace gases in the atmosphere of Mars

The reported detection of methane in the atmosphere of Mars as well as its potentially large seasonal spatial variations challenge our understanding of both the sources and sinks of atmospheric trace gases. The presence of methane suggests ongoing exchange between the subsurface and the atmosphere of potentially biogenic trace gases, while the spatial and temporal variations cannot be accounted for with current knowledge of martian photochemistry. A Joint Instrument Definition Team (JIDT) was asked to assess concepts for a mission that might follow up on these discoveries within the framework of a series of joint missions being considered by ESA and NASA for possible future exploration of Mars. The following is based on the report of the JIDT to the space agencies (Zurek et al., 2009); a synopsis of the report was presented at the Workshop on Mars Methane held in Frascati, Italy, in November 2009. To summarize, the JIDT believed that a scientifically exciting and credible mission could be conducted within the evolving capabilities of the science/telecommunications orbiter being considered by ESA and NASA for possible launch in the 2016 opportunity for Mars.     

The selection and characterization of the <Emphasis Type="Italic">Phobos-Soil</Emphasis> landing sites

This paper shortly describes the selection technique for the landing sites of the Phobos-Soil spacecraft, the characteristics of the Phobos relief, the history of choosing the potential landing sites in the process of working on the project, and the suggestions to shift the landing sites to the region recently imaged by the Mars Express spacecraft with a high spatial resolution under favorable illumination conditions.     

Mars Exploration Rover candidate landing sites as viewed by THEMIS

The analysis of six landing sites that were candidates for the two NASA Mars Exploration Rovers (MER) benefited from recently available image data from the Thermal Emission Imaging Spectrometer (THEMIS) onboard the 2001 Mars Odyssey spacecraft. The combination of daytime and nighttime thermal infrared images from THEMIS supplemented by additional data sets has lead to new or expanded insights into the nature of each landing site. In Meridiani Planum, a layer of lighter-toned, higher thermal inertia material is observable just below the hematite-bearing layer. Gusev Crater displays a more complex stratigraphy than previously observed, including an upper layer with lobate margins. The highest inertia unit of southern Isidis Planitia is confined to topographic lows in the rim/basin margin and does not appear to be due to highland material transported onto the basin floor. The enigmatic, ovoid, blocky terrain on the floor of Melas Chasma displays higher thermal inertia than its surroundings, an indication that it contains coarser or more indurated material than the adjacent aeolian bedforms. The myriad channels of Athabasca Valles display distinctive thermal signatures despite the presence of a bright layer of dust covering the region. The presence of alluvial fans produced from spur-and-gulley erosion of the walls of Eos Chasma demonstrates that mass movements have occurred following the canyon scouring floods.     

An Impacting Descent Probe for Europa and the Other Galilean Moons of Jupiter

We present a study of an impacting descent probe that increases the science return of spacecraft orbiting or passing an atmosphere-less planetary bodies of the solar system, such as the Galilean moons of Jupiter. The descent probe is a carry-on small spacecraft (<100 kg), to be deployed by the mother spacecraft, that brings itself onto a collisional trajectory with the targeted planetary body in a simple manner. A possible science payload includes instruments for surface imaging, characterisation of the neutral exosphere, and magnetic field and plasma measurement near the target body down to very low-altitudes (~1 km), during the probe’s fast (~km/s) descent to the surface until impact. The science goals and the concept of operation are discussed with particular reference to Europa, including options for flying through water plumes and after-impact retrieval of very-low altitude science data. All in all, it is demonstrated how the descent probe has the potential to provide a high science return to a mission at a low extra level of complexity, engineering effort, and risk. This study builds upon earlier studies for a Callisto Descent Probe for the former Europa-Jupiter System Mission of ESA and NASA, and extends them with a detailed assessment of a descent probe designed to be an additional science payload for the NASA Europa Mission.     

Laser-induced breakdown spectroscopy with artificial neural network processing for material identification

Laser-induced breakdown spectroscopy (LIBS) has demonstrated its high potential in measurement of material composition in many areas including space exploration. LIBS instruments will be parts of payloads for the 2011 Mars Science Laboratory NASA-led mission and the ExoMars mission planned by ESA. This paper considers application of artificial neural networks (ANN) for material identification based on LIBS spectra that may be obtained with a portable instrument in ambient conditions. The several classes of materials used in this study included those selected to represent the sites analogues to Mars. In addition, metals and aluminum alloys were used to demonstrate ANN capabilities. Excellent material classification is achieved with single-shot measurements in real time.     

The High Resolution Imaging Science Experiment (HiRISE) during MRO’s Primary Science Phase (PSP)

The High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter (MRO) acquired 8 terapixels of data in 9137 images of Mars between October 2006 and December 2008, covering ∼0.55% of the surface. Images are typically 5-6 km wide with 3-color coverage over the central 20% of the swath, and their scales usually range from 25 to 60 cm/pixel. Nine hundred and sixty stereo pairs were acquired and more than 50 digital terrain models (DTMs) completed; these data have led to some of the most significant science results. New methods to measure and correct distortions due to pointing jitter facilitate topographic and change-detection studies at sub-meter scales. Recent results address Noachian bedrock stratigraphy, fluvially deposited fans in craters and in or near Valles Marineris, groundwater flow in fractures and porous media, quasi-periodic layering in polar and non-polar deposits, tectonic history of west Candor Chasma, geometry of clay-rich deposits near and within Mawrth Vallis, dynamics of flood lavas in the Cerberus Palus region, evidence for pyroclastic deposits, columnar jointing in lava flows, recent collapse pits, evidence for water in well-preserved impact craters, newly discovered large rayed craters, and glacial and periglacial processes. Of particular interest are ongoing processes such as those driven by the wind, impact cratering, avalanches of dust and/or frost, relatively bright deposits on steep gullied slopes, and the dynamic seasonal processes over polar regions. HiRISE has acquired hundreds of large images of past, present and potential future landing sites and has contributed to scientific and engineering studies of those sites. Warming the focal-plane electronics prior to imaging has mitigated an instrument anomaly that produces bad data under cold operating conditions.     

On the first panorama of the surface of Mars

The conditions for video transmission from the panoramic camera of the Mars-3 lander are analyzed. The latter is known to have made the first soft landing on Mars in 1973 during a severe dust storm resulting in damage to the lander. This damage is believed to have reduced the lander’s operation time to 20 s and, apparently, prevented it from achieving the necessary orientation on the surface. If we assume that the lander is lying on its side, then the camera’s panoramic axis would be not vertical, but nearly horizontal. In such a case, we can reproduce, by removing the noise and interferences from the video signal by modern methods, a panoramic fragment, which can help assess the structure of the surface near the landing site of Mars-3.     

Results from the Huygens probe on Titan

The Cassini–Huygens mission, comprising the NASA Saturn Orbiter and the ESA Huygens Probe, arrived at Saturn in late June 2004. The Huygens probe descended under parachute in Titan’s atmosphere on 14 January 2005, 3 weeks after separation from the Orbiter. We discuss here the breakthroughs that the Huygens probe, in conjunction with the Cassini spacecraft, brought to Titan science. We review the achievements ESA’s Huygens probe put forward and the context in which it operated. The findings include new localized information on several aspects of Titan science: the atmospheric structure and chemical composition; the aerosols distribution and content; the surface morphology and composition at the probe’s landing site; the winds, the electrical properties, and the implications on the origin and evolution of the satellite.