The Lunar Geophysical Network Landing Sites Science Rationale
Heidi Fuqua Haviland, Renee C. Weber, Clive R. Neal, Philippe Lognonné, Raphaël F. Garcia, Nicholas Schmerr, Seiichi Nagihara, Robert Grimm, Douglas G. Currie, … 展开作者
Heidi Fuqua Haviland, Renee C. Weber, Clive R. Neal, Philippe Lognonné, Raphaël F. Garcia, Nicholas Schmerr, Seiichi Nagihara, Robert Grimm, Douglas G. Currie, Simone Dell'Agnello, Thomas R. Watters, Mark P. Panning, Catherine L. Johnson, Ryuhei Yamada, Martin Knapmeyer, Lillian R. Ostrach, Taichi Kawamura, Noah Petro, Paul M. Bremner
The Lunar Geophysical Network (LGN) mission is proposed to land on the Moon in 2030 and deploy packages at four locations to enable geophysical measurements for 6-10 years. Returning to the lunar surface with a long-lived geophysical network is a key next step to advance lunar and planetary science. LGN will greatly expand our primarily Apollo-based knowledge of the deep lunar interior by identifying and characterizing mantle melt layers, as well as core size and state. To meet the mission objectives, the instrument suite provides complementary seismic, geodetic, heat flow, and electromagnetic observations. We discuss the network landing site requirements and provide example sites that meet these requirements. Landing site selection will continue to be optimized throughout the formulation of this mission. Possible sites include the P-5 region within the Procellarum KREEP Terrane (PKT; (lat:$15^{\circ}$; long:$-35^{\circ}$), Schickard Basin (lat:$-44.3^{\circ}$; long:$-55.1^{\circ}$), Crisium Basin (lat:$18.5^{\circ}$; long:$61.8^{\circ}$), and the farside Korolev Basin (lat:$-2.4^{\circ}$; long:$-159.3^{\circ}$). Network optimization considers the best locations to observe seismic core phases, e.g., ScS and PKP. Ray path density and proximity to young fault scarps are also analyzed to provide increased opportunities for seismic observations. Geodetic constraints require the network to have at least three nearside stations at maximum limb distances. Heat flow and electromagnetic measurements should be obtained away from terrane boundaries and from magnetic anomalies at locations representative of global trends. An in-depth case study is provided for Crisium. In addition, we discuss the consequences for scientific return of less than optimal locations or number of stations.
Geophysical imaging of the lunar near-surface structure will be key for in situ resource utilization, identification of hazards for crews and infrastructure, and answering science questions on the formation and interior of the Moon. The goal of this white paper is to highlight the value of ground-based geophysical experiments by a crew and to outline a series of experiments to address key science questions. Specifically, we propose for the Artemis III crewed mission multidisciplinary investigations using geophysical methods such as seismic, seismological, ground penetrating radar, and electrom…
This study estimates the cost of building lunar landing pads and examines whether any construction methods are economically superior to others. Some proposed methods require large amounts of mass transported from the Earth, others require high energy consumption on the lunar surface, and others have a long construction time. Each of these factors contributes direct and indirect costs to lunar activities. The most important economic variables turn out to be the transportation cost to the lunar surface and the magnitude of the program delay cost imposed by a construction method. The cost of a la…
Crater size-frequency distribution (CSFDs) measurements allow the derivation of absolute model ages (AMAs) for geological units across various terrestrial bodies in the Solar System based on body-specific adjustments to the lunar chronology (e.g., Hartmann, 1970; Neukum et al., 1975, 1983, 2001; Stoeffler et al., 2001, 2006; Hiesinger et al., 2012; Robbins, 2014). Thus, it is important to revisit and test the accuracy of the lunar chronology using data from recent lunar missions (e.g., Hiesinger et al., 2000, 2012, 2015; Rajmon and Spudis, 2004; Stoeffler et al., 2006), as well as newer analys…
Small scale jet-induced erosion experiments are useful for identifying the scaling of erosion with respect to the various physical parameters (gravity, grain size, gas velocity, gas density, grain density, etc.), and because they provide a data set for benchmarking numerical flow codes. We have performed experiments varying the physical parameters listed above (e.g., gravity was varied in reduced gravity aircraft flights). In all these experiments, a subsonic jet of gas impinges vertically on a bed of sand or lunar soil simulant forming a localized scour hole beneath the jet. Videography captu…
Since the Apollo program or earlier it has been widely believed that the lunar regolith was compacted through vibrations including nearby impact events, thermal stress release in the regolith, deep moon quakes, and shallow moon quakes. Experiments have shown that vibrations both compact and re-loosen regolith as a function of depth in the lunar soil column and amplitude of the vibrational acceleration. Experiments have also identified another process that is extremely effective at compacting regolith: the expansion and contraction of individual regolith grains due to thermal cycling in the upp…
This article describes the characterization activities of the landing sites currently envisaged for the Lunar Lander mission of the European Space Agency. These sites have been identified in the South Pole Region (-85° to -90° latitude) based on favourable illumination conditions, which make it possible to have a long-duration mission with conventional power and thermal control subsystems, capable of enduring relatively short periods of darkness (in the order of tens of hours), instead of utilising Radioisotope Heating Units. The illumination conditions are simulated at the potential landing s…
Air radon concentration measurement is useful for research on geophysical effects, but it is strongly sensitive to site geology and many geophysical and microclimatic processes such as wind, ventilation, air humidity and so on that induce very big fluctuations on the concentration of radon in air. On the contrary, monitoring the radon concentration in soil by measuring the thermal neutron flux reduces environmental effects. In this paper we report some experimental results on the natural thermal neutron flux as well as the concentration of air radon and its variations at 4300 m a.s.l. These re…
Roberts' model of lunar soil erosion beneath a landing rocket has been updated in several ways to predict the effects of future lunar landings. The model predicts, among other things, the number of divots that would result on surrounding hardware due to the impact of high velocity particulates, the amount and depth of surface material removed, the volume of ejected soil, its velocity, and the distance the particles travel on the Moon. The results are compared against measured results from the Apollo program and predictions are made for mitigating the spray around a future lunar outpost.
Several physical mechanisms are involved in excavating granular materials beneath a vertical jet of gas. These occur, for example, beneath the exhaust plume of a rocket landing on the soil of the Moon or Mars. A series of experiments and simulations have been performed to provide a detailed view of the complex gas/soil interactions. Measurements have also been taken from the Apollo lunar landing videos and from photographs of the resulting terrain, and these help to demonstrate how the interactions extrapolate into the lunar environment. It is important to understand these processes at a funda…
The Constellation Project's planned return to the moon requires numerous landings at the same site. Since the top few centimeters are loosely packed regolith, plume impingement from the Lander ejects the granular material at high velocities. Much work is needed to understand the physics of plume impingement during landing in order to protect hardware surrounding the landing sites. While mostly qualitative in nature, the Apollo Lunar Module landing videos can provide a wealth of quantitative information using modern photogrammetry techniques. The authors have used the digitized videos to quanti…
The lunar geological record has much to tell us about the earliest history of the Solar System, the origin and evolution of the Earth-Moon system, the geological evolution of rocky planets, and the near-Earth cosmic environment throughout Solar System history. In addition, the lunar surface offers outstanding opportunities for research in astronomy, astrobiology, fundamental physics, life sciences and human physiology and medicine. This paper provides an interdisciplinary review of outstanding lunar science objectives in all of these different areas. It is concluded that addressing them satisf…
The CosmoQuest virtual community science platform facilitates the creation and implementation of astronomical research projects performed by citizen scientists. One such project, called Moon Mappers, aids in determining the feasibility of producing crowd-sourced cratering statistics of the surface of the Moon. Lunar crater population statistics are an important metric used to understand the formation and evolutionary history of lunar surface features, to estimate relative and absolute model ages of regions on the Moon's surface, and to establish chronologies for other planetary surfaces via ex…
Moon Zoo is a citizen science project that utilises internet crowd-sourcing techniques. Moon Zoo users are asked to review high spatial resolution images from the Lunar Reconnaissance Orbiter Camera (LROC), onboard NASAs LRO spacecraft, and perform characterisation such as measuring impact crater sizes and identify morphological features of interest. The tasks are designed to address issues in lunar science and to aid future exploration of the Moon. We have tested various methodologies and parameters therein to interrogate and reduce the Moon Zoo crater location and size dataset against a vali…
Geodetically Anchored 0.30m Digital Elevation Model of the Chandrayaan-3 Vikram Landing Site from Chandrayaan-2 Orbital High Resolution Camera (OHRC) Stereo Imagery
Liquid water is one of the key elements in the search for possible life outside of the Earth and has a wide range of consequences on various chemical and geological processes. The InSight probe landed on Mars with a special equipment dedicated to examine geophysical characteristics and internal heat flow of the planet and some meteorological instruments also included in the payload. We examine the annual and daily variations of near-surface relative humidity and surface temperature calculated from the General Circulation Model (GCM) at Elysium Planitia, the landing site of InSight and search f…
Optimizing Earth-Moon Transfer and Cislunar Navigation: Integrating Low-Energy Trajectories, AI Techniques and GNSS-R Technologies
Beihang University（北京航空航天大学）；Regional Centre for Space Science and Technology Education in Asia & the Pacific (Affiliated to the United Nations) (RCSSTEAP), Hangzhou International Innovation Institute of Beihang University（联合国附属空间科技教育亚太区域中心，北京航空航天大学杭州国际创新研究院）
Impact cratering is likely a primary agent of regolith generation on airless bodies. Regolith production via impact cratering has long been a key topic of study since the Apollo era. The evolution of regolith due to impact cratering, however, is not well understood. A better formulation is needed to help quantify the formation mechanism and timescale of regolith evolution. Here, we propose an analytically derived stochastic model that describes the evolution of regolith generated by small, simple craters. We account for ejecta blanketing as well as regolith infilling of the transient crater ca…
Tod’Aers；Space Generation Advisory Council（太空世代咨询委员会）；Moscow Aviation Institute（莫斯科航空学院）；Univerité Sultan Moulay Slimane（苏丹穆莱·斯利曼大学）
In recent years, understanding asteroids has shifted from light worlds to geological worlds by exploring modern spacecraft and advanced radar and telescopic surveys. However, flyby in 2029 will be an opportunity to conduct an internal geophysical study and test the current hypothesis on the effects of tidal forces on asteroids. The Earth-Apophis mission is driven by additional factors and scientific goals beyond the unique opportunity for natural experimentation. However, the internal geophysical structures remain largely unknown. Understanding the strength and internal integrity of asteroids …
