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By one estimate, the solar wind has deposited more than 1 million tons of helium-3 (3 He) on the Moon's surface. [62] Materials on the Moon's surface contain helium-3 at concentrations estimated between 1.4 and 15 parts per billion (ppb) in sunlit areas, [1] [63] [64] and may contain concentrations as much as 50 ppb in permanently shadowed ...
Argon-40, helium-4, oxygen and/or methane (CH 4), nitrogen (N 2) and/or carbon monoxide (CO), and carbon dioxide (CO 2)) were detected by in-situ detectors placed by the Apollo astronauts. [10] The average daytime abundances of the elements known to be present in the lunar atmosphere, in atoms per cubic centimeter, are as follows: Argon: 20,000 ...
Helium-4 nuclei are bosons, containing an even number of spin 1 ⁄ 2 particles. This is a direct result of the addition rules for quantized angular momentum. At low temperatures (about 2.17 K), helium-4 undergoes a phase transition: A fraction of it enters a superfluid phase that can be roughly understood as a type of Bose–Einstein ...
The same vehicle could deliver back to Earth, among other cargo, resources including helium 3 mined from the moon. Its 150-ton capacity could make it the perfect vehicle to create the first trade ...
The stability of helium-4 is the reason that hydrogen is converted to helium-4, and not deuterium (hydrogen-2) or helium-3 or other heavier elements during fusion reactions in the Sun. It is also partly responsible for the alpha particle being by far the most common type of baryonic particle to be ejected from an atomic nucleus; in other words ...
4 He, 20 Ne, and 40 Ar gases were determined to be the most abundant species in the lunar exosphere. [60] [61] The helium and neon were found to be supplied by the solar wind. [60] On August 17, 2015, based on studies with the LADEE spacecraft, NASA scientists reported the detection of neon in the exosphere of the Moon. [62]
Of the nuclei, about 90% are simple protons (i.e., hydrogen nuclei); 9% are alpha particles, identical to helium nuclei; and 1% are the nuclei of heavier elements, called HZE ions. [10] These fractions vary highly over the energy range of cosmic rays. [11] A very small fraction are stable particles of antimatter, such as positrons or ...
The most common isotope, helium-4, is produced on Earth by alpha decay of heavier radioactive elements; the alpha particles that emerge are fully ionized helium-4 nuclei. Helium-4 is an unusually stable nucleus because its nucleons are arranged into complete shells. It was also formed in enormous quantities during Big Bang nucleosynthesis. [113]