A Simple Way of Simulating Insolation on a Rotating Body with a Commercial Solar Simulator

The surfaces of all solid bodies in the solar system, planets, moons, comets and asteroids, experience short-term temporal variations of solar irradiation which depend on their respective spin rates. These so-called insolation cycles affect temperature variations, climate, photosynthesis in plants, etc. Hence, experimental reproduction of these cycles is important for space analogue simulations. In this short note we describe a simple, low-cost method to simulate diurnal cycles in the laboratory using a type of commercial solar simulator commonly used for experimental investigation in planetary science

A review of volatiles in the Martian interior

Multiple observations from missions to Mars have revealed compelling evidence for a volatile-rich Martian crust. A leading theory contends that eruption of basaltic magmas was the ultimate mechanism of transfer of volatiles from the mantle toward the surface after an initial outgassing related to the crystallization of a magma ocean. However, the concentrations of volatile species in ascending magmas and in their mantle source regions are highly uncertain. This work and this special issue of Meteoritics & Planetary Science summarize the key findings of the workshop on Volatiles in the Martian Interior (Nov. 3–4, 2014), the primary open questions related to volatiles in Martian magmas and their source regions, and the suggestions of the community at the workshop to address these open questions

The Specific Heat of Astro-materials: Review of Theoretical Concepts, Materials, and Techniques

We provide detailed background, theoretical and practical, on the specific heat of minerals and mixtures thereof, ‘astro-materials,’ as well as background information on common minerals and other relevant solid substances found on the surfaces of solar system bodies. Furthermore, we demonstrate how to use specific heat and composition data for lunar samples and meteorites as well as a new database of endmember mineral heat capacities (the result of an extensive literature review) to construct reference models for the isobaric specific heat cP as a function of temperature for common solar system materials. Using a (generally linear) mixing model for the specific heat of minerals allows extrapolation of the available data to very low and very high temperatures, such that models cover the temperature range between 10 K and 1000 K at least (and pressures from zero up to several kbars). We describe a procedure to estimate cP(T) for virtually any solid solar system material with a known mineral composition, e.g., model specific heat as a function of temperature for a number of typical meteorite classes with known mineralogical compositions. We present, as examples, the cP(T) curves of a number of well-described laboratory regolith analogs, as well as for planetary ices and ‘tholins’ in the outer solar system. Part II will review and present the heat capacity database for minerals and compounds and part III is going to cover applications, standard reference compositions, cP(T) curves, and a comparison with new and literature experimental dat

MASCOT’s in situ analysis of asteroid Ryugu in the context of regolith samples and remote sensing data returned by Hayabusa2

The Hayabusa2 mission provided a unique data set of asteroid Ryugu that covers a wide range of spatial scale from the orbiter remote sensing instruments to the returned samples. The MASCOT lander that was delivered onto the surface of Ryugu aimed to provide context for these data sets by producing in situ data collected by a camera (MasCam), a radiometer (MARA), a magnetometer (MasMag) and a spectrometer (MicrOmega). In this work, we evaluate the success of MASCOT as an integrated lander to bridge the gap between orbiter and returned sample analysis. We find that MASCOT’s measurements and derivatives thereof, including the rock morphology, colour in the visible wavelengths, possible meteorite analogue, density, and porosity of the rock at the landing site are in good agreement with those of the orbiter and the returned samples. However, it also provides information on the spatial scale (sub-millimetres to centimetres) at which some physical properties such as the thermal inertia and reflectance undergo scale-dependent changes. Some of the in situ observations such as the presence of clast/inclusions in rocks and the absence of fine particles at the landing site was uniquely identified by MASCOT. Thus, we conclude that the delivery of an in situ instrument like MASCOT provides a valuable data set that complements and provides context for remote sensing and returned sample analyses

LRAD – A Radiometer for the Lunar South Ppole Hopper µNOVA

The Lunar Prospector discovery of areas of neutron suppression and the subsequent interpretation of hydrogen enrichment near the lunar poles brought the possibility of volatile resources sequestered at the poles to the forefront of the lunar science community. Subsequently the LCROSS experiment showed that water ice is present within at least one permanently shadowed region (PSR) near the south pole and that it can be stable over geological timescales inside permanently shadowed regions (PSRs). Analysis of UV observations gathered by the Lunar Reconnaissance Orbiter Diviner instrument are consistent with the presence of surface frost in some PSRs with temperatures below 110 K. Further, the depth-to-diameter ratios of simple craters as determined from Lunar Orbiter Laser Altimeter (LOLA) altimetric measurements indicate that deposits of water ice in these cold traps may be up to 50 m thick. Moreover, water ice may be present in small PSRs at scales down to, and below 10 meters [5]. Such small-scale cold traps could significantly increase water inventory estimates and eventually simplify extraction

Results from a Comparison of Approximate Analytical Solutions with a Detailed Numerical Inversion Analysis to Determine the Thermal Conductivity of the Regolith at the Mars InSight Landing Site Using Data from HP3 Heating Experiments

A direct measurement of the regolith thermal conductivity at the Mars InSight landing site (4.50°, 132.62°E) was made by heating experiments using the physical properties package (HP3) of the Mars InSight mission. Temperature and time data from these heating experiments, after removal of background temperature variations, were analyzed using a finite element model for which Monte Carlo simulations were run varying regolith thermal conductivity, density, thermal contact conductance between the probe and the regolith to determine parameter combinations that best fit the heating curve. In terms of simulating details of heating experiment this data reduction and numerical inversion is as complete as possible within the current constraints of the experiment. However, no information was included in the model concerning regolith thermal conductivity variations radial to the probe caused during penetration of the probe

Thermal Modeling of Raman Spectra of Forsterite in the Framework of Phobos Surface Mineralogy: Supporting Science of RAX on the JAXA MMX Mission

Thermal modeling of Raman spectra of forsterite in the framework of Phobos environment supporting the synergetic work between RAX and MiniRAD in JAXA MMX mission

In-Situ Radiometric Investigation of Phobos using the MMX Rover’s miniRAD Instrument.

The JAXA MMX sample return mission to the martian moons will deliver a rover to the surface of Phobos that will investigate the landing area using its navigation cameras (NavCams), its regolith facing cameras (WheelCams), its Raman spectrometer (RAX), as well as its mid infrared radiometer (miniRAD). The distance that can be travelled by the Rover depends on the yet unknown terrain properties, but is estimated to range from a few meters to hundreds of meters. The rover and its instruments will operate on the surface of Phobos for at least 100 days