Shijie Wang

JMSS-1: a new Martian soil simulant

It is important to develop Martian soil simulants that can be used in Mars exploration programs and Mars research. A new Martian soil simulant, called Jining Martian Soil Simulant (JMSS-1), was developed at the Lunar and Planetary Science Research Center at the Institute of Geochemistry, Chinese Academy of Sciences. The raw materials of JMSS-1 are Jining basalt and Fe oxides (magnetite and hematite). JMSS-1 was produced by mechanically crushing Jining basalt with the addition of small amounts of magnetite and hematite. The properties of this simulant, including chemical composition, mineralogy, particle size, mechanical properties, reflectance spectra, dielectric properties, volatile content, and hygroscopicity, have been analyzed. On the basis of these test results, it was demonstrated that JMSS-1 is an ideal Martian soil simulant in terms of chemical composition, mineralogy, and physical properties. JMSS-1 would be an appropriate choice as a Martian soil simulant in scientific and engineering experiments in China’s Mars exploration in the future.

In-Situ Water Production by Reducing Ilmenite

Water is considered to be a fundamental condition of human’s colonization of the moon. The supply of oxygen is essential to the utilization of most lunar resources. According to the result of rough calculation, the cost for delivering oxygen from earth to moon for a ten-people lunar base will be nearly 5 to 9 billion dollars a year (Schrunk 1999; Taylor and Carrier 1993; Duke 2003). The cost is so high that water cannot be entirely supported by transportation from the Earth. Nevertheless, there are considerable mineral reserves in lunar soil. Compared to transporting water from earth directly, it is more economical to extract it from the lunar soil. The effects of meteorites, solar wind and cosmic ray make most of the lunar surface covered with a layer of lunar soil. The thickness of lunar soil is approximately 4~5 meters at the mare and >10 meters on the highland. The only practical source of water in the lunar soil is igneous minerals which contain typically 40 to 50% oxygen as oxides. The major minerals are ilmenite, anorthite, and olivine. All these oxides can provide oxygen and water to the lunar base even though some of them cannot be easily reduced. Compared with oxides of silicon, aluminum, titanium, calcium or magnesium, it is much more easily to extract oxygen from iron oxide such as ilmenite.

Difference of brightness temperatures between 19.35 GHz and 37.0 GHz in CHANG＇E-1 MRM： implications for the burial of shallow bedrock at lunar low latitude

Indications of buried lunar bedrock may help us to understand the tectonic evolution of the Moon and provide some clues for formation of lunar regolith. So far, the information on distribution and burial depth of lunar bedrock is far from sufficient. Due to good penetration ability, microwave radiation can be a potential tool to ameliorate this problem. Here, a novel method to estimate the burial depth of lunar bedrock is presented using microwave data from Chang’E-1 (CE-1) lunar satellite. The method is based on the spatial variation of differences in brightness temperatures between 19.35 GHz and 37.0 GHz (ΔTB). Large differences are found in some regions, such as the southwest edge of Oceanus Procellarum, the area between Mare Tranquillitatis and Mare Nectaris, and the highland east of Mare Smythii. Interestingly, a large change of elevation is found in the corresponding region, which might imply a shallow burial depth of lunar bedrock. To verify this deduction, a theoretical model is derived to calculate the ΔTB. Results show that ΔTB varies from 12.7 K to 15 K when the burial depth of bedrock changes from 1 m to 0.5 m in the equatorial region. Based on the available data at low lunar latitude (30°N-30°S), it is thus inferred that the southwest edge of Oceanus Procellarum, the area between Mare Tranquillitatis and Mare Nectaris, the highland located east of Mare Smythii, the edge of Pasteur and Chaplygin are the areas with shallow bedrock, the burial depth is estimated between 0.5 m and 1 m.

Condition of Solar Radiation on the Moon

Solar radiation is an exterior heat source of the Moon and represents a key resource with respect to returning to the Moon. It controls the variation of lunar-surface temperature during the lunation, and changes the thermal radiation properties of the lunar surface. In lunar Earth-based exploration, orbital exploration, and manned and unmanned lunar surface activities, solar radiation is an important factor which should be considered.