Comment on “Statistics for orbital neutron spectroscopy of the Moon and other planetary bodies” by R. S. Miller

Abstract White dwarfs that have accreted planetary bodies are a powerful probe of the bulk composition of exoplanetary material. In this paper, we present a Bayesian model to explain the abundances observed in the atmospheres of 202 DZ white dwarfs by considering the heating, geochemical differentiation, and collisional processes experienced by the planetary bodies accreted, as well as gravitational sinking. The majority (>60%) of systems are consistent with the accretion of primitive material. We attribute the small spread in refractory abundances observed to a similar spread in the initial planet-forming material, as seen in the compositions of nearby stars. A range in Na abundances in the pollutant material is attributed to a range in formation temperatures from below 1,000 K to higher than 1,400 K, suggesting that pollutant material arrives in white dwarf atmospheres from a variety of radial locations. We also find that Solar System-like differentiation is common place in exo-planetary systems. Extreme siderophile (Fe, Ni or Cr) abundances in 8 systems require the accretion of a core-rich fragment of a larger differentiated body to at least a 3σ significance, whilst one system shows evidence that it accreted a crust-rich fragment. In systems where the abundances suggest that accretion has finished (13/202), the total mass accreted can be calculated. The 13 systems are estimated to have accreted masses ranging from the mass of the Moon to half that of Vesta. Our analysis suggests that accretion continues for 11Myrs on average.

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Absence of a long-lived lunar paleomagnetosphere

Science Advances ◽

10.1126/sciadv.abi7647 ◽

2021 ◽

Vol 7 (32) ◽

pp. eabi7647

Author(s):

John A. Tarduno ◽

Rory D. Cottrell ◽

Kristin Lawrence ◽

Richard K. Bono ◽

Wentao Huang ◽

...

Keyword(s):

Magnetic Field ◽

Lunar Regolith ◽

The Moon ◽

Earth’S Magnetosphere ◽

Solar Winds ◽

Planetary Bodies ◽

Earth's Magnetosphere ◽

Impact Glass ◽

Magnetic Inclusions

Determining the presence or absence of a past long-lived lunar magnetic field is crucial for understanding how the Moon’s interior and surface evolved. Here, we show that Apollo impact glass associated with a young 2 million–year–old crater records a strong Earth-like magnetization, providing evidence that impacts can impart intense signals to samples recovered from the Moon and other planetary bodies. Moreover, we show that silicate crystals bearing magnetic inclusions from Apollo samples formed at ∼3.9, 3.6, 3.3, and 3.2 billion years ago are capable of recording strong core dynamo–like fields but do not. Together, these data indicate that the Moon did not have a long-lived core dynamo. As a result, the Moon was not sheltered by a sustained paleomagnetosphere, and the lunar regolith should hold buried 3He, water, and other volatile resources acquired from solar winds and Earth’s magnetosphere over some 4 billion years.

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Human Planetary Exploration

Advances in Public Policy and Administration - Promoting Productive Cooperation Between Space Lawyers and Engineers ◽

10.4018/978-1-5225-7256-5.ch014 ◽

2019 ◽

pp. 225-240

Author(s):

Sophie Gruber

Keyword(s):

Planetary Exploration ◽

Lessons Learned ◽

The Moon ◽

Hardware Development ◽

The Future ◽

Planetary Bodies ◽

New Challenges ◽

Human Exploration

The human exploration of planetary bodies started with the Apollo missions to the Moon, which provided valuable lessons learned and experience for the future human exploration. Based on that, the design of hardware and operations need to further be developed to also overcome the new challenges, which arise when planning crewed missions to Mars and beyond. This chapter provides an overview about the environment and structure of the Red Planet and discusses the challenges on operations and hardware correlated to it. It further provides insights into the considerations regarding the hardware development which need to be investigated and defined before launching a crewed mission to Mars.

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Advances in Cosmochemistry Enabled by Antarctic Meteorites

Annual Review of Earth and Planetary Sciences ◽

10.1146/annurev-earth-082719-055815 ◽

2020 ◽

Vol 48 (1) ◽

pp. 233-258

Author(s):

Meenakshi Wadhwa ◽

Timothy J. McCoy ◽

Devin L. Schrader

Keyword(s):

Solar System ◽

Planetary Science ◽

The Moon ◽

Origin And Evolution ◽

Lunar Meteorite ◽

Planetary Bodies ◽

The Antarctic ◽

Melt Pockets ◽

Scientific Advances

At present, meteorites collected in Antarctica dominate the total number of the world's known meteorites. We focus here on the scientific advances in cosmochemistry and planetary science that have been enabled by access to, and investigations of, these Antarctic meteorites. A meteorite recovered during one of the earliest field seasons of systematic searches, Elephant Moraine (EET) A79001, was identified as having originated on Mars based on the composition of gases released from shock melt pockets in this rock. Subsequently, the first lunar meteorite, Allan Hills (ALH) 81005, was also recovered from the Antarctic. Since then, many more meteorites belonging to these two classes of planetary meteorites, as well as other previously rare or unknown classes of meteorites (particularly primitive chondrites and achondrites), have been recovered from Antarctica. Studies of these samples are providing unique insights into the origin and evolution of the Solar System and planetary bodies. ▪ Antarctic meteorites dominate the inventory of the world's known meteorites and provide access to new types of planetary and asteroidal materials. ▪ The first meteorites recognized to be of lunar and martian origin were collected from Antarctica and provided unique constraints on the evolution of the Moon and Mars. ▪ Previously rare or unknown classes of meteorites have been recovered from Antarctica and provide new insights into the origin and evolution of the Solar System.

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A Small Surface-Based Infrared Spectrometer for the Exploration of the Moon and Other Planetary Bodies

Advances in Imaging ◽

10.1364/fts.2009.fmc3 ◽

2009 ◽

Author(s):

Louis Moreau ◽

John Spray ◽

Philippe Giaccari ◽

Suporn Boonsue ◽

Lucy Thompson

Keyword(s):

The Moon ◽

Small Surface ◽

Planetary Bodies ◽

Infrared Spectrometer

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Ethical and Social Aspects of a Return to the Moon—A Geological Perspective

Geosciences ◽

10.3390/geosciences9010012 ◽

2018 ◽

Vol 9 (1) ◽

pp. 12 ◽

Cited By ~ 2

Author(s):

Vera Assis Fernandes

Keyword(s):

Solar System ◽

Lunar Surface ◽

Surface Current ◽

Social Impacts ◽

Social Aspects ◽

The Moon ◽

International Treaties ◽

Self Reflection ◽

Planetary Bodies ◽

Collaborative Space

The forward planning of the return of Humans to the lunar surface as envisioned by different national and collaborative space agencies requires consideration of the fragility and pristine nature of the lunar surface. Current international treaties are outdated and require immediate action for their update and amendment. This should be taken as an opportunity for self-reflection and potential censoring, enabling a mature, responsible, and iterated sequence of decisions prior to returning. The protocols developed for assessing the ethical and social impacts of Humans on the lunar surface will provide a blueprint for planning future exploration activities on other planetary bodies in the Solar System and beyond.

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Intergrating morpho-stratigraphic and spectral units on Mercury and the Moon: Updates from the PLANMAP project

10.5194/egusphere-egu2020-19741 ◽

2020 ◽

Author(s):

Cristian Carli ◽

Francesca Zambon ◽

Francesca Altieri ◽

Carlos Brandt ◽

Angelo Pio Rossi ◽

...

Keyword(s):

Imaging System ◽

Planetary Science ◽

Hyperspectral Data ◽

Regions Of Interest ◽

The European Union ◽

The Moon ◽

Geophysical Research ◽

Horizon 2020 ◽

Geological Maps ◽

Planetary Bodies

The numerous past and present space missions dedicated to the Solar System planetary bodies exploration, provided a huge amount of data so far. In particular, data acquired by cameras and spectrometers allowed for producing morpho-stratigraphic and mineralogical maps for many planets, satellites and minor bodies. Despite the considerable progresses, the integration of these products is still poorly addressed. To date, no geological maps of planetary bodies other than the Earth, containing both the information, are available yet. In this context, one of the main goals the &#8220;European Union's Horizon 2020 - PLANetary MAPping (PLANMAP)&#8221; project [1] is to provide, for the first time, highly informative geological maps of specific regions of interest on the Moon, Mercury and Mars, taking into account datasets publicly available in the Planetary Data System (PDS) database [2].Here, we show the results achieved during the first two years of the project by the PLANMAP &#8220;Compositional unit definition Work Package&#8221;. In particular, we focused on specific areas, such as Hokusai quadrangle (22&#176;-60&#176; N, 0&#176;-90&#176;W) and Beethoven (13.24&#176;S- 28.39&#176; S; 116.1&#176;- 132.32&#176;W, 630 km diameter) and Rembrandt (24.58&#176;S- 41.19&#176;S, 261.72&#176;- 282.73&#176;W, 716 km diameter) basins on Mercury, and the Apollo basin (10 &#176; &#8211;60 &#176; S, 125 &#176; &#8211;175 &#176; W, 492 km diameter) within the northeastern edge of the ~ 2500 km South Pole-Aitken (SPA) basin on the Moon [3]. For this work, we considered the multi-color images acquired by the Mercury Dual Imaging System - Wide Angle Camera (MDIS-WAC) [3] onboard the MESSENGER mission and hyperspectral data provided by the Moon Mineralogy Mapper (M3) [4] onboard the Chandrayaan-1 mission. After data calibration and the instrumental artifacts removal, we have photometrically corrected the data to derive multi- and hyper-spectral reflectance maps, afterwards we defined appropriate spectral indices to eventually obtain the spectral unit maps of these regions of interest. In next step, we will integrate the spectral unit maps obtained with the morpho-stratigraphic ones provided by other PLANMAP work packages [5, 6, 7] to merge the information and finally retrieve geological units.&#160;This work is funded by the European Union&#8217;s Horizon 2020 research grant agreement No 776276- PLANMAP and by the Italian Space Agency (ASI) within the SIMBIO-SYS project (ASI-INAF agreement 2017-47-H).&#160;References &#160;[1] https://planmap.eu/[2] https://pds.nasa.gov/[3] S. Edward Hawkins III et al., 2007, Space Science Reviews, 131, 247&#8211;338.[4] Pieters, C. E. et al., 2009, CURRENT SCIENCE, 96 (4).[5] Brandt, C. et al., 2020 EGU General Assembly 2020.[6] Ivanov, M.A., et al., 2018, Journal of Geophysical Research, 123 (10), 2585-2612.[7] Wright, J., et al., 2019, 50th Lunar and Planetary Science Conference.

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Open questions in lunar science (invited talk)

10.5194/epsc2021-851 ◽

2021 ◽

Author(s):

James Head

Keyword(s):

Solar System ◽

Planetary Science ◽

Lunar Exploration ◽

The Moon ◽

Origin And Evolution ◽

Lunar Science ◽

The Earth ◽

Planetary Bodies ◽

Over Time

The Earth&#8217;s Moon is a cornerstone and keystone in the understanding of the origin and evolution of the terrestrial, Earth-like planets.&#160; It is a cornerstone in that most of the other paradigms for the origin, modes of crustal formation (primary, secondary and tertiary), bombardment history, role of impact craters and basins in shaping early planetary surfaces and fracturing and modifying the crust and upper mantle, volcanism and the formation of different types of secondary crust, and petrogenetic models where no samples are available, all have a fundamental foundation in lunar science.&#160; The Moon is a keystone in that knowledge of the Moon holds upright the arch of our understand of the terrestrial planets. It is thus imperative to dedicate significant resources to the continued robotic and human exploration of this most accessible of other terrestrial planetary bodies, and to use this cornerstone and keystone as a way to frame critical questions about the Solar System as a whole, and to explore other planetary bodies to modify and strengthen the lunar paradigm.&#160;&#160;&#160; What is the legacy, the long-term impact of our efforts? The Apollo Lunar Exploration Program revealed the Earth as a planet, showed the inextricable links of the Earth-Moon system, and made the Solar System our neighborhood. We now ask: What are our origins and where are we heading?: We seek to understand the origin and evolution of the Moon, the Moon&#8217;s links to the earliest history of Earth, and its lessons for exploration and understanding of Mars and other terrestrial planets. A basis for our motivation is the innate human qualities of curiosity and exploration, and the societal/species-level need to heed Apollo 16 Commander John Young&#8217;s warning that &#8220;Single-planet species don&#8217;t survive!&#8221;. These perspectives impel us to learn the lessons of off-Earth, long-term, long-distance resupply and self-sustaining presence, in order to prepare for the exploration of Mars and other Solar System destinations.&#160; Key questions in this lunar exploration endeavor based on a variety of studies and analyses (1-3) include: -How do planetary systems form and evolve over time and when did major events in our Solar System occur? How did planetary interiors differentiate and evolve through time, and how are interior processes expressed through surface-atmosphere interactions? -What processes shape planetary surfaces and how do these surfaces record Solar System history? -How do worlds become habitable and how is habitability sustained over time? -Why are the atmospheres and climates of planetary bodies so diverse, and how did they evolve over time? -Is there life elsewhere in the Solar System? Specific lunar goals and objectives will be outlined in this broad planetary science context. &#160; References: 1. Carle Pieters et al. (2018) http://www.planetary.brown.edu/pdfs/5480.pdf, 2. Lunar Exploration Analysis Group, https://www.lpi.usra.edu/leag/. 3) Erica Jawin et al. Planetary Science Priorities for the Moon in the Decade 2023-2033: Lunar Science is Planetary Science.

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