Lunar soil
From Wikipedia, the free encyclopedia
Lunar soil is defined as that found on the surface of the Moon. Its properties can differ significantly from those of terrestrial soil. It is essentially devoid of moisture and air, two important components found in soil on Earth.
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[edit] Solar Weathering processes
The major Solar Weathering processes involved in the formation of lunar soil are Comminution, Agglutination, Solar Wind Spallatation and Implantation, and Fire Fountaning. A brief description of each follows:
Comminution: breaking of rocks and minerals into smaller particles;
Agglutination: welding of mineral and rock fragments together by micrometeorite-impact-produced glass;
Solar Wind Spallatation and Implantation: sputtering caused by impacts of high energy particles;
Fire Fountaining: deposition of Dark-Mantled (DM) deposits, such as the shorty crater orange soil.
[edit] Soil properties
Many questions arise relative to the exact soil properties found on the Moon. The significance of acquiring appropriate knowledge of lunar soil properties is great - all future structures, ground transportation networks, and waste disposal systems to name a few examples, depend on real-world experimental data obtained from testing of lunar soil samples. The load-carrying capability of the soil is an important parameter in the design of such structures on Earth. Due to a myriad of meteorite impacts (with velocities greater than 100,000 mph), the lunar surface is covered with a thin layer of 'lunar dust', commonly referred to as lunar regolith. The dust is electrically charged and 'sticks' to any surface it comes in contact with. Soil is commonly said to become very dense beneath the top layer of regolith. Other factors which may affect the properties of lunar soil include large temperature differentials (-380°F<T<+380°F), the presence of a hard vacuum, and the absence of a significant lunar magnetic field (thereby allowing charged solar wind particles to continuously hit the surface of the moon). A weaker gravitational force and the absence of an atmospheric pressure are additional factors which will affect the design of structures on the surface of the Moon. All these factors constitute Space Weathering, largely responsible for the formation of the lunar soil.
Lunar dust poses significant challenges to the implementation of terrestrial technology on the surface of the Moon. Research must be conducted on the following effects of lunar dust:
- Abrasiveness, with regard to friction-bearing surfaces
- Potential effect on coatings, seals, gaskets, optical lenses, windows, electrical components, etc
- Potential for settling on all thermal and optical surfaces, such as solar cells and mirrors
- Physiological effects on humans - particularly the lung, lymph, and cardiovascular systems
[edit] Gallery
 Relative Concentration Of Various Elements On The Lunar Surface |
 Relative Concentration (in weight ppm) of Various Elements on Lunar Highlands, Lunar Lowlands, and Earth |
[edit] References
- Park, J.S.; Y. Liu, K. D. Kihm, and L. A. Taylor. Micro-Morphology And Toxicological Effects Of Lunar Dust. Lunar and Planetary Science XXXVII (2006)-. Retrieved on March 8, 2007. “The particle size distribution of the lunar dust from Apollo 17 sample 77051 has been determined using SEM imaging analysis. The size-distribution data features an approximate Gaussian distribution with a single mode at around 300-nm. The reactivation surface area of highly porous “Swiss-cheese” particles is about 26% higher than a sphere. The morphologies of dust grains have been classified based upon their four types: 1) spherical; 2) angular blocks; 3) glass shards; and 4) irregular (ropey or Swiss-cheese). These data will assist the medical researchers in their studies of the toxicological effects of inhalation of lunar dust by humans.”
- Young, Kelly. "Lint rollers may collect dangerous Moon dust", New Scientist, 06 March 2007. Retrieved on March 7, 2007. “While hailed as a potential source of oxygen and metals, Moon dust is a concern because doctors fear the smallest grains could lodge in astronauts' lungs, possibly causing long-term health effects.”
