scholarly journals Constraints on olivine-rich rock types on the Moon as observed by Diviner and M3 : Implications for the formation of the lunar crust

2016 ◽  
Vol 121 (7) ◽  
pp. 1342-1361 ◽  
Author(s):  
J. A. Arnold ◽  
T. D. Glotch ◽  
P. G. Lucey ◽  
E. Song ◽  
I. R. Thomas ◽  
...  
Keyword(s):  
The Moon ◽  
Lunar Crust ◽  
Rock Types

Structure in the upper lunar crust

1977 ◽  
Vol 285 (1327) ◽  
pp. 469-473 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Elastic Moduli ◽  
Velocity Profiles ◽  
Depth Range ◽  
The Moon ◽  
Rock Layer ◽  
Lunar Crust ◽  
Seismic Profiles ◽  
Lunar Samples

Estimates are made of the degree of lithification and of structure densities which are compatible with lunar in situ seismic profiles in the top 30 km of the Moon. Estimates are based on comparison of results of passive and active lunar seismic experiments with the pressure dependence of elastic moduli for various classes of lunar samples. Competent rock, such as igneous rock or recrystallized breccias with crack porosity of not more than about 0.5 % are required to satisfy velocity profiles in the depth range 1-30 km. Velocity profiles in the upper 1 km are best satisfied by comminuted material to highly fractured lithic units. These estimates constrain those thermal and shock histories which are compatible with lunar seismic results. After crystallization, or recrystallization, rock below 1 km cannot have been exposed to more than moderate shock levels. In the uppermost 1 km, an unannealed and broken rock layer would imply low thermal conductivity resulting in possible temperatures at 1 km depth of several hundred kelvins.

Chemical composition of the Moon's 'primary' crust – a clue at a terrestrial origin

2020 ◽  
Author(s):  
Audrey Vorburger ◽  
Peter Wurz ◽  
Manuel Scherf ◽  
Helmut Lammer ◽  
André Galli ◽  
...  
Keyword(s):  
Lunar Surface ◽  
Major Elements ◽  
The Moon ◽  
Lunar Crust ◽  
Near Surface ◽  
Origin And Evolution ◽  
The Past ◽  
The Earth ◽  
Terrestrial Origin ◽  
In The Beginning

<p>The Moon is one of the best characterized objects in space science, yet its origin still actively researched. Available orbital, geophysical, and geochemical information imposes clear restrictions on the origin and evolution of the Earth-Moon system (e.g., Canup 2008, 2012; Ćuk and Stewart 2012; Young et al. 2016). In regard to geochemical constraints, one of the most puzzling conundrums is posed by the similar isotopic fingerprints of the Earth and the Moon (e.g., Wiechert et al. 2001; Armytage et al. 2012; Zhang et al. 2012; Young et al. 2016; Schiller et al. 2018), together with the apparent lunar depletion in volatile elements (e.g., Ringwood and Kesson 1977; Wanke et al. 1977; Albarède et al. 2015; Taylor 2014). This apparent lunar volatile depletion is most notable in the low K content in comparison to U, a finding based on chemical analyses of samples collected from the lunar surface and lunar meteorites, and on spectroscopic observations of the lunar near-surface, despite both having been heavily processed in the past ~ 4.4 billion years.</p><p>In the past 4.4 billion years, space has been a harsh environment for our Moon, especially in the beginning, when the young Sun was still very active and the young Moon was continuously bombarded by meteorites of varying sizes. Solar wind and micro-meteoritic interactions with the lunar surface led to rapid and intensive processing of the lunar crust. Hence, the K/U depletion trend observable on today's lunar surface does not necessarily reflect a K/U ratio valid for the Moon in its entirety. We model the evolution of the abundances of the major elements over the past 4.3 to 4.4 billion years to derive the composition of the original lunar crust. Accounting for this processing, our model results show that the original crust is much less depleted in volatiles than the surface observable today, exhibiting a K/U ratio compatible with Earth and the other terrestrial planets, which strengthens the theory of a terrestrial origin for the Moon.</p>

scholarly journals Contraction or expansion of the Moon's crust during magma ocean freezing?

2014 ◽  
Vol 372 (2024) ◽  
pp. 20130240 ◽  
Author(s):  
Linda T. Elkins-Tanton ◽  
David Bercovici
Keyword(s):  
Lower Crust ◽  
The Moon ◽  
Magma Ocean ◽  
Lunar Crust ◽  
Initial State ◽  
Early State ◽  
Gravity Measurements ◽  
Viscous Relaxation ◽  
Tectonic Features

The lack of contraction features on the Moon has been used to argue that the Moon underwent limited secular cooling, and thus had a relatively cool initial state. A cool early state in turn limits the depth of the lunar magma ocean. Recent GRAIL gravity measurements, however, suggest that dikes were emplaced in the lower crust, requiring global lunar expansion. Starting from the magma ocean state, we show that solidification of the lunar magma ocean would most likely result in expansion of the young lunar crust, and that viscous relaxation of the crust would prevent early tectonic features of contraction or expansion from being recorded permanently. The most likely process for creating the expansion recorded by the dikes is melting during cumulate overturn of the newly solidified lunar mantle.

Newton novel magnetic instrument. Potential application to unveil key questions as the origin of the Moon

2020 ◽  
Author(s):  
José Luis Mesa Uña ◽  
Marina Díaz Michelena ◽  
Francisco Javier de Frutos Hernánsanz ◽  
Claudio Aroca Hernández-Ros ◽  
Marina Pérez Jiménez ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Temporal Variations ◽  
Magnetic Characteristics ◽  
Potential Contribution ◽  
The European Union ◽  
The Moon ◽  
Lunar Crust ◽  
Sensors And Actuators ◽  
Earth Planet

<p>The main objective of this contribution is to present the evolution of NEWTON novel magnetic susceptometer for planetary exploration, a state of the art sensor for the measurement of the complex magnetic susceptibility developed in the frame of an EU H2020 funded project [1].</p><p>The magnetic susceptibility is a complex parameter dependent on the external magnetic field amplitude, direction and frequency. NEWTON susceptometer has been developed to determine the magnetic susceptibility of rocks and soils, with the capability to determine not only the real part but also the imaginary part of the susceptibility.</p><p>The calibration and validation process for the susceptometer prototype casted very good results in comparison with other commercial and high resolution laboratory devices, reaching a resolution in the order of χ = 10<sup>−4</sup> (I.S. Vol. Susceptibility), representative of Earth, Moon and Mars rocks. The critical parts of the prototype have been subjected to different tests, i.e. vibration and TVT, to verify the capability to withstand the hard environmental conditions of interplanetary missions.</p><p>In this work we discuss the potential contribution of NEWTON instrument on the technical and scientific objectives achievement in future investigations on the Moon, either as payload during in-situ exploration with rovers or in sample return missions, providing a useful tool for fast in place sample analysis.</p><p>There are still open questions regarding Moon’s magnetic field and geological characteristics of the satellite. Most hypotheses to explain the magnetic characteristics and anomalies on the lunar surface invoke a thermally driven core dynamo during its Pre-Nectarian and Nectarian history [2]. However, this theory is problematical given the small size of the core and the required strong magnetic field strength of an ancient dynamo. Further investigations on the lunar samples from missions [3] indicate ancient magnetic fields with intensities of <1 to 120 μT for the period between 4.2 to 4.0 Ga. This huge range of intensities may indicate that the Moon’s magnetic field experienced extreme high temporal variations [2]. Even if considering large uncertainties, dynamo models should consider paleointensities of at least ~35 μT for this high-field period.</p><p>The use of scientific instruments like NEWTON susceptometer in rover exploration missions could shed some light on the ancient dynamo magnetic field, the magnetic and mineral composition of the lunar crust and other unanswered questions from the Moon.</p><p>Acknowledgements:</p><p>This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 730041 and the Spanish Programme of Research, Development and Innovation oriented to the challenges of the society under grant ESP2017-88930-R.</p><p> </p><p><strong>References:</strong></p><p>[1] M.Diaz Michelena, J.L Mesa Uña, M. Perez Jimenez, M. Maicas Ramos, P. Cobos Arribas, C. Aroca Hernandez-Ros, Sensors and Actuators, A: Physical, volume 263, pages 471-479 (2017)</p><p>[2] Tikoo, S.M., Weiss, B.P., Cassata, W.S., Shuser, D.L., Gattacceca, J., Lima, E.A., Suavet, C., Nimmo, F. & Fuller, M.D. Earth Planet. Sci. Lett., 404: 89-97 (2014)</p><p>[3] Tsunakawa, H., Takahashi, F., Shimizu, H., Shibuya, H., & Matsushima, M. Icarus 228: 35-53 (2014).</p><p>[3] Fuller, M. (1974). Reviews of Geophysics, 12 – 1, 101-103 (1974)</p>

Topographic-Compositional Units on the Moon and the Early Evolution of the Lunar Crust

Science ◽  
1994 ◽  
Vol 266 (5192) ◽  
pp. 1855-1858 ◽  
Author(s):  
P. G. Lucey ◽  
P. D. Spudis ◽  
M. Zuber ◽  
D. Smith ◽  
E. Malaret
Keyword(s):  
Early Evolution ◽  
The Moon ◽  
Lunar Crust

scholarly journals P-bearing olivines of lunar rocks: sources and localization in the lunar crust

2019 ◽  
Vol 64 (8) ◽  
pp. 803-825
Author(s):  
S. I. Demidovaa ◽  
M. O. Anosova ◽  
N. N. Kononkova ◽  
T. Ntaflos ◽  
F. Brandstätter
Keyword(s):  
Late Stage ◽  
The Moon ◽  
Local Distribution ◽  
Lunar Crust ◽  
Lunar Material ◽  
Incompatible Elements ◽  
Lunar Samples ◽  
Lunar Rocks ◽  
Mare Basalts

Fragments of P-bearing olivine have been studied in lunar highland, mare and mingled meteorites and in «Apollo-14», «Luna-16, -20, -24» lunar samples. Olivine contains up to 0.5 wt.% P2O5 and has variable MG# number. It is associated with anorthite, pyroxene and accessory spinel group minerals, Ti and Zr oxides, phosphates, troilite and Fe-Ni metal. Three possible sources of P-bearing olivine were found in lunar material: 1) highland anorthositic-noritic-troctolitic rocks enriched in incompatible elements and thought to be related to high-Mg suite rocks: 2) late-stage products of mare basalts crystallization; 3) unusual olivine-orthopyroxene intergrowths either of meteoritic or lunar origin. Enrichment in incompatible elements may be resulted from both crystallization processes (source 2) and KREEP assimilation (sources 1 and 3). However following metasomatic processes can lead to some addition of phosphorus and other elements. The rarity of P-bearing olivines points either to the low abundance or local distribution of their sources in the lunar crust. Association with mare basalts specifies the highland-mare boundary. The presence of the evolved rocks in the studied breccias suggests possible connection of some sources with recently discovered granitic domes in Procellarum Ocean. That means the P-bearing sources are mainly localized on the visible side of the Moon.

The Lunar Environment Monitoring Station (LEMS)

2020 ◽  
Author(s):  
Mehdi Benna ◽  
Nicholas Schmerr ◽  
Menelaos Sarantos ◽  
Hop Bailey ◽  
Daniel Gershman ◽  
...  
Keyword(s):  
Interplanetary Dust ◽  
Dust Particles ◽  
Monitoring Station ◽  
Environment Monitoring ◽  
The Moon ◽  
Lunar Crust ◽  
Interplanetary Dust Particles ◽  
Surface Activities ◽  
Lunar Environment ◽  
Lunar Exosphere

<p>The Lunar Environment Monitoring Station (LEMS) is an instrument concept funded by NASA’s Development of Advanced Lunar Instrumentation (DALI) Program, and undergoing maturation at NASA's Goddard Space Flight Center. LEMS has been proposed to the NASA's recent call for Payloads and Research Investigations on the Surface of the Moon (PRISM).</p><p>LEMS is a compact, autonomous, self-sustaining and long-lasting instrument suite that enables in situ, continuous, long-term monitoring of the lunar exosphere and of the most relevant natural and manmade controlling processes (infall of interplanetary dust particles (IDP), influx of solar wind and magnetospheric particles, EUV irradiation, interior outgassing, disturbances by landers and human surface activities). LEMS can be delivered to the surface of the Moon by crewed or robotic missions. Once deployed (on a deck or directly on the surface), LEMS will operate day and night for a nominal duration of 2 years without requiring any additional support or resources from the carrying asset.</p><p>LEMS integrates a Mass Spectrometer, a Laser Retro-reflector Array, a Lunar Micrometeoroid Monitor, a Lunar Energetic Ion Analyzer, and a 3-axis Seismometer. These sensors will collect concurrent observations that will lead to a comprehensive, time-resolved, and geographically-localized characterization of the composition and dynamics of volatiles gases in the lunar exosphere as a response to variations in solar forcing, IDP flux, seismicity, and known manmade events. Furthermore, owing to its expected longevity, LEMS will also improve upon the success of the Apollo Passive Seismic Experiment (PSE) by providing a new generation of seismological measurements that will address unanswered questions by the PSEs. These questions include the size and state of the lunar core, homogeneity of the mantle, variation in crustal thickness, the mechanism for deep moonquakes, and the relationship between shallow seismicity and the current tectonic state of the lunar crust.</p><p>With its complementary and integrated multi-sensors and its autonomous concept of operation, LEMS is a science-enabling investigation that combines capabilities, in a single duplicable instrument package. The duplicative nature of the LEMS design enables a network of stations that focuses on exospheric and geophysical measurements at the Moon to become viable options. Finally, the self-sustaining architecture of LEMS provides a model design of future payloads that can take advantage of more commercial or scientific flight opportunities to the Moon while requiring no further support for operation from their carrying assets.</p>

A young Moon-forming giant impact at 70–110 million years accompanied by late-stage mixing, core formation and degassing of the Earth

2008 ◽  
Vol 366 (1883) ◽  
pp. 4163-4181 ◽  
Author(s):  
Alex N Halliday
Keyword(s):  
Isotopic Composition ◽  
The Moon ◽  
Lunar Crust ◽  
Core Formation ◽  
Volatile Elements ◽  
Giant Impact ◽  
Isotope Data ◽  
The Earth ◽  
Isotopic Effects ◽  
Late Veneer

New W isotope data for lunar metals demonstrate that the Moon formed late in isotopic equilibrium with the bulk silicate Earth (BSE). On this basis, lunar Sr isotope data are used to define the former composition of the Earth and hence the Rb–Sr age of the Moon, which is 4.48±0.02 Ga, or 70–110 Ma (million years) after the start of the Solar System. This age is significantly later than had been deduced from W isotopes based on model assumptions or isotopic effects now known to be cosmogenic. The Sr age is in excellent agreement with earlier estimates based on the time of lunar Pb loss and the age of the early lunar crust (4.46±0.04 Ga). Similar ages for the BSE are recorded by xenon and lead–lead, providing evidence of catastrophic terrestrial degassing, atmospheric blow-off and significant late core formation accompanying the ca 100 Ma giant impact. Agreement between the age of the Moon based on the Earth's Rb/Sr and the lead–lead age of the Moon is consistent with no major losses of moderately volatile elements from the Earth during the giant impact. The W isotopic composition of the BSE can be explained by end member models of (i) gradual accretion with a mean life of roughly 35 Ma or (ii) rapid growth with a mean life of roughly 10 Ma, followed by a significant hiatus prior to the giant impact. The former assumes that approximately 60 per cent of the incoming metal from impactors is added directly to the core during accretion. The latter includes complete mixing of all the impactor material into the BSE during accretion. The identical W isotopic composition of the Moon and the BSE limits the amount of material that can be added as a late veneer to the Earth after the giant impact to less than 0.3±0.3 per cent of ordinary chondrite or less than 0.5±0.6 per cent CI carbonaceous chondrite based on their known W isotopic compositions. Neither of these on their own is sufficient to explain the inventories of both refractory siderophiles such as platinum group elements and rhenium, and volatiles such as sulphur, carbon and water.

scholarly journals A long-lived magma ocean on a young Moon

2020 ◽  
Vol 6 (28) ◽  
pp. eaba8949 ◽  
Author(s):  
M. Maurice ◽  
N. Tosi ◽  
S. Schwinger ◽  
D. Breuer ◽  
T. Kleine
Keyword(s):  
Thermal Conductivity ◽  
Partial Melting ◽  
Time Scale ◽  
Solidification Time ◽  
Heat Extraction ◽  
The Moon ◽  
Magma Ocean ◽  
Lunar Crust ◽  
Lunar Samples ◽  
Remarkable Agreement

A giant impact onto Earth led to the formation of the Moon, resulted in a lunar magma ocean (LMO), and initiated the last event of core segregation on Earth. However, the timing and temporal link of these events remain uncertain. Here, we demonstrate that the low thermal conductivity of the lunar crust combined with heat extraction by partial melting of deep cumulates undergoing convection results in an LMO solidification time scale of 150 to 200 million years. Combining this result with a crystallization model of the LMO and with the ages and isotopic compositions of lunar samples indicates that the Moon formed 4.425 ± 0.025 billion years ago. This age is in remarkable agreement with the U-Pb age of Earth, demonstrating that the U-Pb age dates the final segregation of Earth’s core.

Nickel for Your Thoughts: Urey and the Origin of the Moon

Science ◽  
1982 ◽  
Vol 217 (4563) ◽  
pp. 891-898 ◽  
Author(s):  
Stephen G. Brush
Keyword(s):  
Solar System ◽  
The Moon ◽  
Lunar Crust ◽  
Lunar Landing ◽  
The Earth ◽  
History Of ◽  
Siderophile Elements ◽  
Origin Of The Moon ◽  
Manned Lunar Landing

The theories of Harold C. Urey (1893-1981) on the origin of the moon are discussed in relation to earlier ideas, especially George Howard Darwin's fission hypothesis. Urey's espousal of the idea that the moon had been captured by the earth and has preserved information about the earliest history of the solar system led him to advocate a manned lunar landing. Results from the Apollo missions, in particular the deficiency of siderophile elements in the lunar crust, led him to abandon the capture selenogony and tentatively adopt the fission hypothesis.

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