scholarly journals Do Impulsive Solar-Energetic-Electron (SEE) Events Drive High-Voltage Charging Events on the Nightside of the Moon?

2021 ◽  
Vol 8 ◽  
Author(s):  
Joseph E. Borovsky ◽  
Gian Luca Delzanno
Keyword(s):  
Solar Wind ◽  
Relativistic Electron ◽  
Lunar Surface ◽  
Energetic Electron ◽  
Relativistic Electrons ◽  
Time Varying ◽  
The Sun ◽  
The Moon ◽  
Lunar Wake ◽  
Electrical Potentials

When the Earth’s moon is in the supersonic solar wind, the darkside of the Moon and the lunar plasma wake can be very dangerous charging environments. In the absence of photoelectron emission (dark) and in the absence of cool plasma (wake), the emission or collection of charge to reduce electrical potentials is difficult. Unique extreme charging events may occur during impulsive solar-energetic-electron (SEE) events when the lunar wake is dominated by relativistic electrons, with the potential to charge and differentially charge objects on and above the lunar surface to very-high negative electrical potentials. In this report the geometry of the magnetic connections from the Sun to the lunar nightside are explored; these magnetic connections are the pathways for SEEs from the Sun. Rudimentary charging calculations for objects in the relativistic-electron environment of the lunar wake are performed. To enable these charging calculations, secondary-electron yields for impacts by relativistic electrons are derived. Needed lunar electrical-grounding precautions for SEE events are discussed. Calls are made 1) for future dynamic simulations of the plasma wake in the presence of time-varying SEE-event relativistic electrons and time-varying solar-wind magnetic-field orientations and 2) for future charging calculations in the relativistic-electron wake environment and on the darkside lunar surface.

Microrelief of the Lunar Surface and the Probable Ways of its Formation

1962 ◽  
Vol 14 ◽  
pp. 385-390 ◽  
Author(s):  
V. V. Sharonov
Keyword(s):  
Seventeenth Century ◽  
Lunar Surface ◽  
Full Moon ◽  
The Sun ◽  
The Moon ◽  
Laboratory Measurements ◽  
Galileo Galilei ◽  
Photometric Observations ◽  
Reflection Of Light

Already in the Seventeenth century Galileo Galilei [1] had turned his attention to the peculiarity of the reflection of light from the lunar surface, which consisted of the fact that the disk of the full Moon exhibits no darkening towards the limb. Galilei explained this by assuming that, besides the mountainous macrorelief on the Moon, which could be observed in the telescope, there existed an ubiquitous microrelief pointing to a very rough structure of the lunar surface. Modern photometric observations have fully confirmed this conclusion and have enabled us to unravel many peculiarities of this microrelief—in particular, the rather unique law of reflection from the lunar surface, expressed by a reflection diagram very elongated in the direction of the Sun. The comparison with the laboratory measurements carried out by Orlova [2] showed that the elements of this relief should possess vertical, or very steep, walls and sharp broken-off edges reminding one by their structure of laced volcanic slags and lapilli. At the same time the dimensions of these irregularities are found to be small—of the order of limilmetres or centimetres [3].

scholarly journals KAGUYA observation of global emissions of indigenous carbon ions from the Moon

2020 ◽  
Vol 6 (19) ◽  
pp. eaba1050 ◽  
Author(s):  
Shoichiro Yokota ◽  
Kentaro Terada ◽  
Yoshifumi Saito ◽  
Daiba Kato ◽  
Kazushi Asamura ◽  
...  
Keyword(s):  
Solar Wind ◽  
Lunar Surface ◽  
Carbon Ions ◽  
The Moon ◽  
Considerable Influence ◽  
Lunar Orbiter ◽  
Volatile Element ◽  
Emission Fluxes ◽  
Formation And Evolution ◽  
Global Emissions

Carbon is a volatile element that has a considerable influence on the formation and evolution of planetary bodies, although it was previously believed to be depleted in the Moon. We present observations by the lunar orbiter KAGUYA of carbon ions emitted from the Moon. These emissions were distributed over almost the total lunar surface, but amounts were differed with respect to lunar geographical areas. The estimated emission fluxes to space were ~5.0 × 104 per square centimeter per second, which is greater than possible ongoing supplies from the solar wind and micrometeoroids. Our estimates demonstrate that indigenous carbon exists over the entire Moon, supporting the hypothesis of a carbon-containing Moon, where the carbon was embedded at its formation and/or was transported billions of years ago.

scholarly journals Пылевые звуковые солитоны в плазме запыленной экзосферы Луны

2021 ◽  
Vol 47 (9) ◽  
pp. 29
Author(s):  
С.И. Копнин ◽  
С.И. Попель
Keyword(s):  
Solar Wind ◽  
Lunar Surface ◽  
Soliton Solutions ◽  
Dust Particles ◽  
Charged Dust ◽  
The Moon ◽  
Electrons And Ions ◽  
Dust Acoustic

This paper shows a possibility of the existence and propagation of dust acoustic solitons in plasmas of dusty exosphere of the Moon, which contains, in addition to electrons and ions of the solar wind and photoelectrons from the lunar surface, also charged dust particles, as well as photoelectrons emitted from the surfaces of these particles. Soliton solutions are found and the ranges of possible velocities and amplitudes of such solitons are determined depending on the height above the lunar surface for different subsolar angles.

scholarly journals An event study on broadband electric field noises and electron distributions in the lunar wake boundary

2022 ◽  
Vol 74 (1) ◽  
Author(s):  
Masaki N. Nishino ◽  
Yoshiya Kasahara ◽  
Yuki Harada ◽  
Yoshifumi Saito ◽  
Hideo Tsunakawa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Electric Field ◽  
Interplanetary Magnetic Field ◽  
Electric Fields ◽  
Lunar Surface ◽  
Electron Beams ◽  
The Moon ◽  
Link Type ◽  
Electron Distributions

AbstractWave–particle interactions are fundamental processes in space plasma, and some plasma waves, including electrostatic solitary waves (ESWs), are recognised as broadband noises (BBNs) in the electric field spectral data. Spacecraft observations in recent decades have detected BBNs around the Moon, but the generation mechanism of the BBNs is not fully understood. Here, we study a wake boundary traversal with BBNs observed by Kaguya, which includes an ESW event previously reported by Hashimoto et al. Geophys Res Lett 37:L19204 10.1029/2010GL044529 (2010). Focusing on the relation between BBNs and electron pitch-angle distribution functions, we show that upward electron beams from the nightside lunar surface are effective for the generation of BBNs, in contrast to the original interpretation by Hashimoto et al. Geophys Res Lett 37:L19204 10.1029/2010GL044529 (2010) that high-energy electrons accelerated by strong ambipolar electric fields excite ESWs in the region far from the Moon. When the BBNs were observed by the Kaguya spacecraft in the wake boundary, the spacecraft’s location was magnetically connected to the nightside lunar surface, and bi-streaming electron distributions of downward-going solar wind strahl component and upward-going field-aligned beams (at $$\sim$$ ∼ 124 eV) were detected. The interplanetary magnetic field was dominated by a positive $$B_Z$$ B Z (i.e. the northward component), and strahl electrons travelled in the antiparallel direction to the interplanetary magnetic field (i.e. southward), which enabled the strahl electrons to precipitate onto the nightside lunar surface directly. The incident solar wind electrons cause negative charging of the nightside lunar surface, which generates downward electric fields that accelerate electrons from the nightside surface toward higher altitudes along the magnetic field. The bidirectional electron distribution is not a sufficient condition for the BBN generation, and the distribution of upward electron beams seems to be correlated with the BBNs. Ambipolar electric fields in the wake boundary should also contribute to the electron acceleration toward higher altitudes and further intrusion of the solar wind ions into the deeper wake. We suggest that solar wind ion intrusion into the wake boundary is also an important factor that controls the BBN generation by facilitating the influx of solar wind electrons there. Graphical Abstract

A mission proposal for understanding the origin of the lunar water: Scientific concept of the SELPHIE Mission

2020 ◽  
Author(s):  
Yoshifumi Futaana ◽  
Stas Barabash ◽  
Keyword(s):  
Solar Wind ◽  
Surface Water ◽  
Mass Spectrometer ◽  
Lunar Surface ◽  
Cold Trap ◽  
Scientific Concept ◽  
Human Beings ◽  
The Moon ◽  
Baseline Design ◽  
Impact Experiments

<p>We are approaching a new era of space exploration: Utilization of our Moon for Human Beings. Intensive international efforts targeting human activities on the Moon have been initiated, and developed drastically in this decade. The revolution enabling the activities was the discovery of water at the Moon. We envisage utilizing the water for Lunar surface activities, as well as for explorations to farther Deep Space destinations.</p><p>Although multiple datasets have revealed the existence of Lunar water, fundamental scientific questions remain unanswered: Where has the surface and cold trap waters come from? What are the relative roles between solar wind protons and delivery from space for the Lunar surface water? What is the role of transportation of surface water to cold traps? This is the problem area that the SELPHIE (Surface, Exosphere, and Lunar Polar Hydration with Impact Experiments) mission is to reveal. The top-level science question of SELPHIE is "How is the lunar surface water delivered or produced, transported, and accumulated in cold traps?"</p><p>The baseline design of the SELPHIE mission is composed of six scientific sensors (three remote sensing and three in situ sensors) together with two impact experiments: An infrared spectrometer, visible camera, energetic neutral atom telescope, neutral mass spectrometer, solar wind monitor, and dust detector.  These sensors are operated from a 3-axis stabilized SELPHIE orbiter to reveal the comprehensive picture of the lunar water cycle. Two impact experiments (two identical systems, enabling two independent experiments) will be executed to reveal the source of water under cold traps. Each impact experiment contains a 6U cubesat and a small impactor (4 kg). The impactor will impact to a permanently shadowed crater to make ejecta. The cubesat will sound the plume by mass spectrometer and camera.</p><p>The norminal mission period is for 8-12 months, under the quasi-stationary polar orbit of the Moon (30-200 km altitudes). The pericenter is above the South Pole. The total mass of 600 kg (dry mass) with 61 kg payload mass is the baseline, while a further mass reduction could also be foreseen. The total cost, without payload developement, is within the ESA's F-class mission cost cap (150 MEuro).</p>

The remanent magnetic field of the moon

1977 ◽  
Vol 285 (1327) ◽  
pp. 489-506 ◽  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Lunar Surface ◽  
Empirical Data ◽  
Energetic Particles ◽  
The Moon ◽  
Indirect Measurements ◽  
Apollo Program ◽  
Direct Measurements ◽  
Series Of Experiments

This paper is intended as a review of the empirical data on the remanent magnetic field of the Moon. These data are from direct measurements of the remanent field with magnetometers on the lunar surface and on board the Apollo subsatellites, and indirect measurements derived from studies of the interactions of the solar wind and energetic particles with the Moon. This paper is intended as a review of the empirical data on the remanent magnetic field of the Moon. These data are from direct measurements of the remanent field with magnetometers on the lunar surface and on board the Apollo subsatellites, and indirect measurements derived from studies of the interactions of the solar wind and energetic particles with the Moon. Measurements on the surface of the M oon In a series of experiments performed during the Apollo program, Sonett, Dyal, and coworkers obtained measurements of the Moon’s remanent magnetic field at the sites of Apollos 12, 14, 15 and 16. (Dyal et al. (1974) have recently reviewed this work.) Two types of vector magnetometers were used in these experiments: a fixed, or station instrument; and a portable, or traverse, unit.

Lunar Dust

2020 ◽  
Author(s):  
Alexander V. Zakharov
Keyword(s):  
Solar Wind ◽  
Solar Radiation ◽  
Lunar Surface ◽  
Lunar Regolith ◽  
Dust Particles ◽  
The Moon ◽  
Near Surface ◽  
Lunar Dust ◽  
Research Programs ◽  
The Impact

The surface of the Moon, as well as the surface of an airless body of the solar system, is subject to constant bombardment of micrometeorites, the effects of solar radiation, solar wind, and other space factors. As a result of the impact of high-speed micrometeorites for billions of years, the silicate base of the lunar surface is crushed, turning into particles with an approximately power-law-sized distribution. Given the explosive nature of the occurrence, these particles are characterized by an extremely irregular shape with pointed edges, either droplets close to spheres or conglomerates sintered at high temperatures. The plasma of the solar wind and the solar radiation, especially its ultraviolet part of the spectrum, when interacting with the upper layer of regolith causes a charge of the regolith upper layer and creates a near-surface double layer and an electric field. In this field, regolith particles of micron and submicron sizes can break away from the surface and levitate above the surface. Such dynamic processes lead to the transfer of dust particles over the surface of the Moon, as well as to the scattering of sunlight on these particles. Glows above the lunar surface of this nature were observed by television systems of American and Soviet landers in the early stages of lunar exploration. The American astronauts who landed on the lunar surface during the Apollo program experienced the aggressive properties of lunar dust. The results of the Apollo missions showed that dust particles are one of the main causes of danger to humans, spacecraft systems, and activities on the lunar surface. Based on the results of late 20th- and early 21st-century lunar research, as well as the proposed models, the article discusses the formation of the lunar regolith and the near-surface exosphere of the Moon under the influence of external factors in outer space. Relevant considerations include the causes and conditions of dust particle dynamics, the consequences of these processes as well as possible threats to humans, engineering systems during the implementation of planned research programs, and the exploration of the Moon. Also of relevance are models of the formation of a plasma-dust exosphere, the dynamics of dust particles in the near-surface region, and dust clouds at a distance of several tens of kilometers from the Moon’s surface, based on the available experimental data. The main unresolved problems associated with the dynamics of the dust component of lunar regolith are given, and methods for solving problematic issues are discussed. The Moon research programs of leading space agencies and their role in the study of Moon dust, its dynamics, human impact, and its activities in the implementation of promising programs for the study and exploration of the Moon are examined.

SP4GATEWAY: a Space Plasma Physics Payload Package conceptual design for the Deep Space Gateway Lunar Orbital Platform

2020 ◽  
Author(s):  
Iannis Dandouras ◽  
Pierre Devoto ◽  
Johan De Keyser ◽  
Yoshifumi Futaana ◽  
Ruth Bamford ◽  
...  
Keyword(s):  
Solar Wind ◽  
Plasma Physics ◽  
Conceptual Design ◽  
Lunar Surface ◽  
Space Plasma ◽  
The Moon ◽  
Deep Space ◽  
Space Plasma Physics ◽  
Plasma Environment ◽  
Technical Requirements

<p>The Deep Space Gateway is a crewed platform that will be assembled and operated in the vicinity of the Moon by ESA and its international partners in the early 2020s and will offer new opportunities for fundamental and applied scientific research. The Moon is a unique location to study the deep space plasma environment, due to the absence of a substantial intrinsic magnetic field and the direct exposure to the solar wind, galactic cosmic rays (GCRs) and solar energetic particles (SEPs). However, 5-6 days each orbit, the Moon crosses the tail of the terrestrial magnetosphere facilitating the in-situ study of the terrestrial magnetotail plasma environment as well as atmospheric escape from the ionosphere. When back outside of the magnetosphere, a variety of these and other phenomena, e.g. those driving solar-terrestrial relationships, can be investigated through remote sensing using a variety of imaging techniques. Most importantly, the lunar environment offers a unique opportunity to study the interaction of the solar wind and the magnetosphere with the lunar surface and the lunar surface-bounded exosphere. In preparation of the scientific payload of the Deep Space Gateway, we have undertaken a conceptual design study for a Space Plasma Physics Payload Package onboard the Gateway (SP4GATEWAY). The main goal is first to provide a science rationale for hosting space plasma physics instrumentation on the Gateway and to translate that into a set of technical requirements. A conceptual payload design, that identifies a strawman payload and is compatible with the technical requirements, is then put forward. The final outcome of this project, which is undertaken following an ESA AO, is an implementation plan for this space plasma physics payload package.</p>

Electron drift echoes induced by negative solar wind dynamic pressure pulses

2020 ◽  
Author(s):  
Xiaohan Ma ◽  
Qiugang Zong ◽  
Yixin Hao ◽  
Seth Claudepierre ◽  
Ying Liu
Keyword(s):  
Solar Wind ◽  
Electric Field ◽  
Relativistic Electron ◽  
Pressure Pulse ◽  
Dynamic Pressure ◽  
Energetic Electron ◽  
Interplanetary Shock ◽  
Solar Wind Dynamic Pressure ◽  
Electron Drift ◽  
Field Variation

<div> <div> <div> <p>Sudden dropouts of the relativistic electron fluxes with drift echoes are closely related to a positive solar wind dynamic pressure pulse, such as an interplanetary shock impact on the magnetosphere. In this study, we further examine how magnetospheric energetic particles response to a negative solar wind dynamic pressure pulse on the 11th May 2017. During this event, sudden dropouts of energetic electron fluxes with an energy of 200 keV∼750 keV and enhancements of the relativistic electron fluxes of 0.85 MeV∼2.7 MeV were observed simultaneously by both Van Allen Probes. The periodic electron flux dropout-recovery or enhancement-decay signatures, which are attributed to electron drift behaviors, exhibited energy dependence. Based on the electron phase space density profile and the induced electric field variation, we interpreted this phenomenon as the consequence of radially outward transportationss of electrons caused by the electric field impulse induced by the negative dynamic pressure pulse.</p> </div> </div> </div>

A Photographic Map of the Moon

1962 ◽  
Vol 14 ◽  
pp. 113-115
Author(s):  
D. W. G. Arthur ◽  
E. A. Whitaker
Keyword(s):  
Lunar Surface ◽  
The Moon ◽  
Map Projection

The cartography of the lunar surface can be split into two operations which can be carried on quite independently. The first, which is also the most laborious, is the interpretation of the lunar photographs into the symbolism of the map, with the addition of fine details from telescopic sketches. An example of this kind of work is contained in Johann Krieger'sMond Atlaswhich consists of photographic enlargements in which Krieger has sharpened up the detail to accord with his telescopic impressions. Krieger did not go on either to convert the photographic picture into the line symbolism of a map, or to place this picture on any definite map projection.

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