Lunar Ice: Adsorbed Water on Subsurface Polar Dust

Cocks, F. H.; Klenk, Paul; Watkins, S.A; Simmons, W. Neal; Cocks, J.C; Cocks, E.E; Sussingham, J C

doi:10.1006/icar.2002.6972

Cited by 34 publications

(17 citation statements)

References 67 publications

(98 reference statements)

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“…A chemisorbed or physically strongly adsorbed layer of H 2 O molecules may exist on lunar grains that is stable indefinitely [ Hodges , 2002; Cocks et al , 2002]. Since the stability of this layer is so strong, it may preexist, and our calculations only consider the volatile water.…”

Section: Discussionmentioning

confidence: 99%

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Subsurface migration of H₂O at lunar cold traps

2007

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[1] Permanently shaded areas near the poles of the Moon and Mercury may harbor water ice. We develop a physical model for migration of water molecules in the regolith and discover two pathways that can lead to accumulation of H 2 O in the subsurface. A small fraction of water molecules delivered, either continuously or abruptly, to permanently cold areas diffuses into the regolith and can remain there longer than on the surface. Higher temperatures lead to deeper burial. At constant temperature, this diffusive migration produces less than one molecular layer of volatile H 2 O on grains, because it is driven by differences in surface concentrations. The water is therefore expected to be in adsorbed form, and the amount stored in this fashion could be at most a few hundred ppm of H 2 O. A second pathway is pumping by diurnal temperature oscillations from a transient ice cover that may have formed during a large comet impact. It can lead to high ground ice densities, but the ground ice layer lasts not long beyond the disappearance of the ice cover. Both types of subsurface charging mechanism work best for temperatures typical of permanently shaded areas with sunlit surfaces in their field of view.

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Section: Discussionmentioning

confidence: 99%

“…Transport and deposition of water molecules has been studied previously. To transport and trapping, we add subsurface migration caused by molecular diffusion in the porous regolith, taking a different approach than that used by Cocks et al [2002].…”

Section: Introductionmentioning

confidence: 99%

Subsurface migration of H₂O at lunar cold traps

2007

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“…However, lunar ice delivered to the poles, from various sources suggested by Arnold (1979), can migrate to the subsurface. Cocks et al (2002) details a mechanism whereby ice migrates to the subsurface due to temperature fluctuations and in the process is adsorbed on lunar dust. Salvail and Fanale (1994) simulated that the crater floor of Peary crater (at polar latitude of 88.6°L) has temperatures in the range 70-120 K in the shadowed region.…”

Section: Application To Manned Exploration Of the Moonmentioning

confidence: 99%

Instrumentation for Geological Field Work On the Moon

et al. 2004

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Abstract.A human return to the Moon will require that astronauts are well equipped with instrumentation to aid their investigations during geological field work. Two instruments are described in detail. The first is a portable X-ray Spectrometer, which can provide rapid geochemical analyses of rocks and soils, identify lunar resources and aid selection of samples for return to Earth. The second instrument is the Geological and Radiation environment package (GEORAD). This is an instrument package, mounted on a rover, to perform in-situ measurements on the lunar surface. It can be used for bulk geochemical measurements of rocks and soils (particularly identifying KREEP-enriched rocks), prospect for ice in shadowed areas of craters at the poles and characterise the lunar radiation environment.

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Section: Introductionmentioning

confidence: 99%

“…Despite the reducing environment, ferric iron–bearing minerals have been theorized to form on the lunar surface ( 4 – 6 ). The recognition that the lunar poles harbor water ice led to studies regarding the possibility of alteration due to minerals in contact with ice ( 4 ) or vapor from sublimating ice ( 5 ). In addition, a recent study shows that plasmas sourced from Earth’s upper atmosphere (so called “Earth wind”) may have delivered a substantial amount of oxygen to the lunar surface in the past 2.4 billion years during the passage of the Moon through Earth’s magnetotail ( 7 ).…”

Section: Introductionmentioning

confidence: 99%

Widespread hematite at high latitudes of the Moon

Lucey

Fraeman

et al. 2020

Sci. Adv.

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Hematite (Fe2O3) is a common oxidization product on Earth, Mars, and some asteroids. Although oxidizing processes have been speculated to operate on the lunar surface and form ferric iron–bearing minerals, unambiguous detections of ferric minerals forming under highly reducing conditions on the Moon have remained elusive. Our analyses of the Moon Mineralogy Mapper data show that hematite, a ferric mineral, is present at high latitudes on the Moon, mostly associated with east- and equator-facing sides of topographic highs, and is more prevalent on the nearside than the farside. Oxygen delivered from Earth’s upper atmosphere could be the major oxidant that forms lunar hematite. Hematite at craters of different ages may have preserved the oxygen isotopes of Earth’s atmosphere in the past billions of years. Future oxygen isotope measurements can test our hypothesis and may help reveal the evolution of Earth’s atmosphere.

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Lunar Ice: Adsorbed Water on Subsurface Polar Dust

Cited by 34 publications

References 67 publications

Subsurface migration of H₂O at lunar cold traps

Subsurface migration of H₂O at lunar cold traps

Instrumentation for Geological Field Work On the Moon

Widespread hematite at high latitudes of the Moon

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Lunar Ice: Adsorbed Water on Subsurface Polar Dust

Cited by 34 publications

References 67 publications

Subsurface migration of H2O at lunar cold traps

Subsurface migration of H2O at lunar cold traps

Instrumentation for Geological Field Work On the Moon

Widespread hematite at high latitudes of the Moon

Contact Info

Product

Resources

About

Subsurface migration of H₂O at lunar cold traps

Subsurface migration of H₂O at lunar cold traps