Regolith
Regolith is the layer of rocky or icy debris, sand, and dust made by meteoritic impact that forms the uppermost surface of planets, satellites and asteroids. It is a possible construction material in the form of bricks. Loose regolith may also be used as a radiation shield.
Landscapes with regolith formation have been found that look like they were shaped by the flow of water. Those formations were probably created by "gas-supported density flows". [1]
Composition
The below table gives estimates of mineral composition based on the soil sample measurements performed by two Mars probes. Only the 6 most abundant minerals are listed.
| SiO2 | Fe2O3 | Al2O3 | MgO | CaO | SO3 | |
|---|---|---|---|---|---|---|
| Viking | 46.3 | 19.4 | 7.7 | 6.4 | 6.2 | 7.9 |
| Pathfinder | 48.6 | 17.5 | 8.3 | 7.5 | 6.3 | 5.4 |
The following table shows the results of an analysis of 11 igneous meteorites of Martian origin, which were divided into 5 standard geological categories based on their composition.
| Element | Atoms/gram | ||||
|---|---|---|---|---|---|
| Basalt | Lherzolite | Clinopyroxenite | Orthopyroxenite | Dunite | |
| O | 1.60 X 1022 | 1.58 X 1022 | 1.54 X 1022 | 1.65 X 1022 | 1.51 X 1022 |
| Na | 2.35 X 1020 | 9.15 X 1019 | 1.13 X 1020 | 2.66 X 1019 | 2.51 X 1019 |
| Mg | 1.61 X 1021 | 4.07 X 1021 | 1.79 X 1021 | 3.77 X 1021 | 4.81 X 1021 |
| Al | 8.50 X 1020 | 3.34 X 1020 | 1.94 X 1020 | 1.45 X 1020 | 8.23 X 1019 |
| Si | 5.01 X 1021 | 4.50 X 1021 | 4.88 X 1021 | 5.38 X 1021 | 3.87 X 1021 |
| P | 5.60 X 1019 | 2.00 X 1019 | 3.76 X 1018 | 0 | 6.41 X 1018 |
| K | 1.23 X 1019 | 3.31 X 1018 | 2.93 X 1019 | 1.95 X 1018 | 5.31 X 1018 |
| Ca | 1.06 X 1021 | 4.04 X 1020 | 1.56 X 1021 | 1.98 X 1020 | 6.52 X 1019 |
| Ti | 8.21 X 1019 | 3.28 X 1019 | 2.59 X 1019 | 1.53 X 1019 | 7.60 X 1018 |
| Mn | 4.42 X 1019 | 3.91 X 1019 | 5.69 X 1019 | 4.04 X 1019 | 4.51 X 1019 |
| Fe | 1.58 X 1021 | 1.67 X 1021 | 1.79 X 1021 | 1.46 X 1021 | 2.29 X 1021 |
Open Issues
- How radioactive is regolith?
- What are the compositions of the regolith near possible settlement sites?
References
- ↑ How the landscape is formed to the shape of floods: THE COLLAPSE ORIGIN OF DENSITY FLOWS ON MARS
- ↑ Bell JF, McSween HY, Crisp JA, Morris RV, Murchie SL, Bridges NT,...Soderblom L. (2000). Mineralogic and compositional properties of Martian soil and dust: Results from Mars Pathfinder. Journal of Geophysical Research, 105(E1), 1721-1755. https://doi.org/10.1029/1999JE001060
- ↑ Kim MY, Thibeault SA, Simonsen LC, Wilson JW. (1998). Comparison of Martian Meteorites and Martian Regolith as Shield Materials for Galactic Cosmic Rays. NASA TP-1998-208724. http://hdl.handle.net/2060/19980237030
