The atmosphere of the Moon is very tenuous and insignificant in comparison to that of the Earth. One source of the lunar atmosphere is outgassing—the release of gases such as radon that originate by radioactive decay processes within the crust and mantle. Another important source is generated through the process of sputtering, which involves the bombardment of micrometeorites, solar wind ions, electrons, and sunlight.^[1] Gasses that are released by sputtering can either reimplant into the regolith as a cause of the Moon's gravity, or can be lost to space either by solar radiation pressure or by being swept away by the solar wind magnetic field if they are ionized. The elements sodium (Na) and potassium (K) have been detected using earth-based spectroscopic methods, whereas the element radon-222 and polonium-210 have been inferred from data obtained from the Lunar Prospector alpha particle spectrometer.^[2] Argon-40, He-4, O and/or CH₄, N₂ and/or CO, and CO₂ were detected by in-situ detectors placed by the Apollo astronauts.^[3] Apparent magnitude: up to -12. ... Earth (IPA: , often referred to as the Earth, Terra, the World or Planet Earth) is the third planet in the solar system in terms of distance from the Sun, and the fifth largest. ... General Name, Symbol, Number radon, Rn, 86 Chemical series noble gases Group, Period, Block 18, 6, p Appearance colorless Atomic mass (222) g/mol Electron configuration [Xe] 4f14 5d10 6s2 6p6 Electrons per shell 2, 8, 18, 32, 18, 8 Physical properties Phase gas Density (0 °C, 101. ... Sputtering is a physical process whereby atoms in a solid target material are ejected into the gas phase due to bombardment of the material by energetic ions. ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Atomic mass 22. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Atomic mass 39. ... General Name, Symbol, Number radon, Rn, 86 Chemical series noble gases Group, Period, Block 18, 6, p Appearance colorless Atomic mass (222) g/mol Electron configuration [Xe] 4f14 5d10 6s2 6p6 Electrons per shell 2, 8, 18, 32, 18, 8 Physical properties Phase gas Density (0 °C, 101. ... General Name, Symbol, Number polonium, Po, 84 Chemical series metalloids Group, Period, Block 16, 6, p Appearance silvery Atomic mass (209) g/mol Electron configuration [Xe] 4f14 5d10 6s2 6p4 Electrons per shell 2, 8, 18, 32, 18, 6 Physical properties Phase solid Density (near r. ... NASAs Lunar Prospector The Lunar Prospector mission was the third selected by NASA for full development and construction as part of the Discovery Program. ... An alpha particle is deflected by a magnetic field Alpha particles (named after the first letter in the Greek alphabet, α) are a highly ionizing form of particle radiation which have low penetration. ...

References

1. ^ P. Lucey and 12 coauthors (2006). "Understanding the lunar surface and space-Moon interactions". Reviews in Mineralogy and Geochemistry 60: 83-219.
2. ^ S. Lawson, W. Feldman, D. Lawrence, K. Moore, R. Elphic, and R. Belian (2005). "Recent outgassing from the lunar surface: the Lunar Prospector alpha particle spectrometer". J. Geophys. Res. 110: doi:10.1029/2005JE002433.
3. ^ S. Alan Stern (1999). "The Lunar atmosphere: History, status, current problems, and context". Rev. Geophys. 37: 453-491.