Lunar Sourcebook : a User's Guide to the Moon
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Lunar Impact Crater Identification and Age Estimation with Chang’E
ARTICLE https://doi.org/10.1038/s41467-020-20215-y OPEN Lunar impact crater identification and age estimation with Chang’E data by deep and transfer learning ✉ Chen Yang 1,2 , Haishi Zhao 3, Lorenzo Bruzzone4, Jon Atli Benediktsson 5, Yanchun Liang3, Bin Liu 2, ✉ ✉ Xingguo Zeng 2, Renchu Guan 3 , Chunlai Li 2 & Ziyuan Ouyang1,2 1234567890():,; Impact craters, which can be considered the lunar equivalent of fossils, are the most dominant lunar surface features and record the history of the Solar System. We address the problem of automatic crater detection and age estimation. From initially small numbers of recognized craters and dated craters, i.e., 7895 and 1411, respectively, we progressively identify new craters and estimate their ages with Chang’E data and stratigraphic information by transfer learning using deep neural networks. This results in the identification of 109,956 new craters, which is more than a dozen times greater than the initial number of recognized craters. The formation systems of 18,996 newly detected craters larger than 8 km are esti- mated. Here, a new lunar crater database for the mid- and low-latitude regions of the Moon is derived and distributed to the planetary community together with the related data analysis. 1 College of Earth Sciences, Jilin University, 130061 Changchun, China. 2 Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, 100101 Beijing, China. 3 Key Laboratory of Symbol Computation and Knowledge Engineering of Ministry of Education, College of Computer Science and Technology, Jilin University, 130012 Changchun, China. 4 Department of Information Engineering and Computer ✉ Science, University of Trento, I-38122 Trento, Italy. -
Bombardment History of the Moon: What We Think We Know and What We Don’T Know Donald Bogard, ARES-KR, NASA-JSC, Houston, TX 77058 ([email protected])
Planetary Chronology Workshop 2006 6001.pdf Bombardment History of the Moon: What We Think We Know and What We Don’t Know Donald Bogard, ARES-KR, NASA-JSC, Houston, TX 77058 ([email protected]) Summary. The absolute impact history of and 14 soils show a decrease in the number of the moon and inner solar system can in principle beads with age from ~4 Gyr ago to ~0.4 Gyr ago, be derived from the statistics of radiometric ages followed by a significant increase in beads with of shock-heated planetary samples (lunar or age <0.4 Gyr (2). These authors concluded that meteoritic), from the formation ages of specific the projectile flux had decreased over time, impact craters on the moon or Earth; and from followed by a significant flux increase more age-dating samples representing geologic surface recently. However, this data set has also been units on the moon (or Mars) for which crater interpreted to represent variable rates of impact densities have been determined. This impact melt production as a function of regolith maturity history, however, is still poorly defined. (3). In another study, measured ages of 21 small The heavily cratered surface of the moon is a impact melt clasts in four lunar meteorites from testimony to the importance of impact events in the lunar highlands suggested four to six impact the evolution of terrestrial planets and satellites. events over the period ~2.5-4.0 Gyr ago (4). Lunar impacts range in scale from an early Clearly considerable uncertainty exists in the intense flux of large objects that defined the projectile flux over the past ~3.5 Gyr and whether surface geology of the moon, down to recent, this flux has been approximately constant or smaller impacts that continually generate and exhibited appreciable shorter-term variations. -
Exploring the Bombardment History of the Moon
EXPLORING THE BOMBARDMENT HISTORY OF THE MOON Community White Paper to the Planetary Decadal Survey, 2011-2020 September 15, 2009 Primary Author: William F. Bottke Center for Lunar Origin and Evolution (CLOE) NASA Lunar Science Institute at the Southwest Research Institute 1050 Walnut St., Suite 300 Boulder, CO 80302 Tel: (303) 546-6066 [email protected] Co-Authors/Endorsers: Carlton Allen (NASA JSC) Mahesh Anand (Open U., UK) Nadine Barlow (NAU) Donald Bogard (NASA JSC) Gwen Barnes (U. Idaho) Clark Chapman (SwRI) Barbara A. Cohen (NASA MSFC) Ian A. Crawford (Birkbeck College London, UK) Andrew Daga (U. North Dakota) Luke Dones (SwRI) Dean Eppler (NASA JSC) Vera Assis Fernandes (Berkeley Geochronlogy Center and U. Manchester) Bernard H. Foing (SMART-1, ESA RSSD; Dir., Int. Lunar Expl. Work. Group) Lisa R. Gaddis (US Geological Survey) 1 Jim N. Head (Raytheon) Fredrick P. Horz (LZ Technology/ESCG) Brad Jolliff (Washington U., St Louis) Christian Koeberl (U. Vienna, Austria) Michelle Kirchoff (SwRI) David Kring (LPI) Harold F. (Hal) Levison (SwRI) Simone Marchi (U. Padova, Italy) Charles Meyer (NASA JSC) David A. Minton (U. Arizona) Stephen J. Mojzsis (U. Colorado) Clive Neal (U. Notre Dame) Laurence E. Nyquist (NASA JSC) David Nesvorny (SWRI) Anne Peslier (NASA JSC) Noah Petro (GSFC) Carle Pieters (Brown U.) Jeff Plescia (Johns Hopkins U.) Mark Robinson (Arizona State U.) Greg Schmidt (NASA Lunar Science Institute, NASA Ames) Sen. Harrison H. Schmitt (Apollo 17 Astronaut; U. Wisconsin-Madison) John Spray (U. New Brunswick, Canada) Sarah Stewart-Mukhopadhyay (Harvard U.) Timothy Swindle (U. Arizona) Lawrence Taylor (U. Tennessee-Knoxville) Ross Taylor (Australian National U., Australia) Mark Wieczorek (Institut de Physique du Globe de Paris, France) Nicolle Zellner (Albion College) Maria Zuber (MIT) 2 The Moon is unique. -
Glossary Glossary
Glossary Glossary Albedo A measure of an object’s reflectivity. A pure white reflecting surface has an albedo of 1.0 (100%). A pitch-black, nonreflecting surface has an albedo of 0.0. The Moon is a fairly dark object with a combined albedo of 0.07 (reflecting 7% of the sunlight that falls upon it). The albedo range of the lunar maria is between 0.05 and 0.08. The brighter highlands have an albedo range from 0.09 to 0.15. Anorthosite Rocks rich in the mineral feldspar, making up much of the Moon’s bright highland regions. Aperture The diameter of a telescope’s objective lens or primary mirror. Apogee The point in the Moon’s orbit where it is furthest from the Earth. At apogee, the Moon can reach a maximum distance of 406,700 km from the Earth. Apollo The manned lunar program of the United States. Between July 1969 and December 1972, six Apollo missions landed on the Moon, allowing a total of 12 astronauts to explore its surface. Asteroid A minor planet. A large solid body of rock in orbit around the Sun. Banded crater A crater that displays dusky linear tracts on its inner walls and/or floor. 250 Basalt A dark, fine-grained volcanic rock, low in silicon, with a low viscosity. Basaltic material fills many of the Moon’s major basins, especially on the near side. Glossary Basin A very large circular impact structure (usually comprising multiple concentric rings) that usually displays some degree of flooding with lava. The largest and most conspicuous lava- flooded basins on the Moon are found on the near side, and most are filled to their outer edges with mare basalts. -
TRANSIENT LUNAR PHENOMENA: REGULARITY and REALITY Arlin P
The Astrophysical Journal, 697:1–15, 2009 May 20 doi:10.1088/0004-637X/697/1/1 C 2009. The American Astronomical Society. All rights reserved. Printed in the U.S.A. TRANSIENT LUNAR PHENOMENA: REGULARITY AND REALITY Arlin P. S. Crotts Department of Astronomy, Columbia University, Columbia Astrophysics Laboratory, 550 West 120th Street, New York, NY 10027, USA Received 2007 June 27; accepted 2009 February 20; published 2009 April 30 ABSTRACT Transient lunar phenomena (TLPs) have been reported for centuries, but their nature is largely unsettled, and even their existence as a coherent phenomenon is controversial. Nonetheless, TLP data show regularities in the observations; a key question is whether this structure is imposed by processes tied to the lunar surface, or by terrestrial atmospheric or human observer effects. I interrogate an extensive catalog of TLPs to gauge how human factors determine the distribution of TLP reports. The sample is grouped according to variables which should produce differing results if determining factors involve humans, and not reflecting phenomena tied to the lunar surface. Features dependent on human factors can then be excluded. Regardless of how the sample is split, the results are similar: ∼50% of reports originate from near Aristarchus, ∼16% from Plato, ∼6% from recent, major impacts (Copernicus, Kepler, Tycho, and Aristarchus), plus several at Grimaldi. Mare Crisium produces a robust signal in some cases (however, Crisium is too large for a “feature” as defined). TLP count consistency for these features indicates that ∼80% of these may be real. Some commonly reported sites disappear from the robust averages, including Alphonsus, Ross D, and Gassendi. -
A Zircon U-Pb Study of the Evolution of Lunar KREEP
A zircon U-Pb study of the evolution of lunar KREEP By A.A. Nemchin, R.T. Pidgeon, M.J. Whitehouse, J.P. Vaughan and C. Meyer Abstract SIMS U-Pb analyses show that zircons from breccias from Apollo 14 and Apollo 17 have essentially identical age distributions in the range 4350 to 4200 Ma but, whereas Apollo 14 zircons additionally show ages from 4200 to 3900 Ma, the Apollo 17 samples have no zircons with ages <4200 Ma. The zircon results also show an uneven distribution with distinct peaks of magmatic activity. In explaining these observations we propose that periodic episodes of KREEP magmatism were generated from a primary reservoir of KREEP magma, which contracted over time towards the centre of Procellarum KREEP terrane. Introduction One of the most enigmatic features of the geology of the Moon is the presence of high concentrations of large ion lithophile elements in clasts from breccias from non mare regions. This material, referred to as KREEP (1) from its high levels of K, REE and P, also contains relatively high concentrations of other incompatible elements including Th, U and Zr. Fragments of rocks with KREEP trace element signatures have been identified in samples from all Apollo landing sites (2). The presence of phosphate minerals, such as apatite and merrillite (3); zirconium minerals, such as zircon (4), zirconolite (5) and badelleyite (6), and rare earth minerals such as yttrobetafite (7), are direct expressions of the presence of KREEP. Dickinson and Hess (8) concluded that about 9000 ppm of Zr in basaltic melt is required to saturate it with zircon at about 1100oC (the saturation concentration increases exponentially with increasing temperature). -
Assessment of Spectral Properties of Apollo 12 Landing Site Yann Chemin1, Ian Crawford2, Peter Grindrod2, and Louise Alexander2
Assessment of spectral properties of Apollo 12 landing site Yann Chemin1, Ian Crawford2, Peter Grindrod2, and Louise Alexander2 1Student, Birkbeck Colllege, University of London 2Birkbeck Colllege, University of London Corresponding author: Yann Chemin1 Email address: [email protected] ABSTRACT The geology and mineralogy of the Apollo 12 landing site has been the subject of recent studies that this research attempts to complement from a remote sensing point of view using the Moon Mineralogy Mapper (M3) sensor data, onboard the Chandrayaan-1 lunar orbiter. It is a higher spatial-spectral resolution sensor than the Clementine UVVis sensor and gives the opportunity to study the lunar surface with a comparatively more detailed spectral resolution. We used ISIS and GRASS GIS to study the M3 data. The M3 signatures are showing a monotonic featureless increment, with very low reflectance, suggesting a mature regolith. The regolith maturity is splitting the landing site in a younger Northwest and older Southeast. The mineral identification using the lunar sample spectra from within the Relab database found some similarity to a basaltic rock/glass mix. The spectrum features of clinopyroxene have been found in the Copernican rays and at the landing site. Lateral mixing increases FeO content away from the central part of the ray. The presence of clinopyroxene in the pigeonite basalt in the stratigraphy of the landing site brings forth some complexity in differentiating the Copernican ray’s clinopyroxene from the local source, as the spectra are twins but for their vertical shift in reflectance, reducing away from the central part of the ray. Spatial variations in mineralogy were not found mostly because of the pixel size compared to the landing site area. -
Radar Remote Sensing of Pyroclastic Deposits in the Southern Mare Serenitatis and Mare Vaporum Regions of the Moon Lynn M
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 114, E11004, doi:10.1029/2009JE003406, 2009 Click Here for Full Article Radar remote sensing of pyroclastic deposits in the southern Mare Serenitatis and Mare Vaporum regions of the Moon Lynn M. Carter,1 Bruce A. Campbell,1 B. Ray Hawke,2 Donald B. Campbell,3 and Michael C. Nolan4 Received 21 April 2009; revised 12 July 2009; accepted 3 August 2009; published 5 November 2009. [1] We use polarimetric radar observations to study the distribution, depth, and embedded rock abundance of nearside lunar pyroclastic deposits. Radar images were obtained for Mare Vaporum and the southern half of Mare Serenitatis; the imaged areas contain the large Rima Bode, Mare Vaporum, Sulpicius Gallus, and Taurus-Littrow pyroclastic deposits. Potential pyroclastic deposits at Rima Hyginus crater, the Tacquet Formation, and a dome in Mare Vaporum are also included. Data were acquired at S band (12.6 cm wavelength) using Arecibo Observatory and the Green Bank Telescope in a bistatic configuration. The S band images have resolutions between 20 and 100 m/pixel. The pyroclastic deposits appear dark to the radar and have low circular polarization ratios at S band wavelengths because they are smooth, easily penetrable by radar waves, and generally contain few embedded blocks. Changes in circular polarization ratio (CPR) across some of the pyroclastic deposits show areas with increased rock abundance as well as deposits that are shallower. Radar backscatter and CPR maps are used to identify fine-grained mantling deposits in cases where optical and near-infrared data are ambiguous about the presence of pyroclastics. -
Highresolution Local Gravity Model of the South Pole of the Moon From
GeophysicalResearchLetters RESEARCH LETTER High-resolution local gravity model of the south pole 10.1002/2014GL060178 of the Moon from GRAIL extended mission data 1,2 2 2,3 2 Key Points: Sander Goossens , Terence J. Sabaka , Joseph B. Nicholas , Frank G. Lemoine , • We present a high-resolution gravity David D. Rowlands2, Erwan Mazarico2,4, Gregory A. Neumann2, model of the south pole of the Moon David E. Smith4, and Maria T. Zuber4 • Improved correlations with topography to higher degrees than 1CRESST, University of Maryland Baltimore County, Baltimore, Maryland, USA, 2NASA Goddard Space Flight Center, global models 3 4 • Improved fits to the data and Greenbelt, Maryland, USA, Emergent Space Technologies, Greenbelt, Maryland, USA, Department of Earth, Atmospheric reduced striping that is present in and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA global models Abstract We estimated a high-resolution local gravity field model over the south pole of the Moon Supporting Information: using data from the Gravity Recovery and Interior Laboratory’s extended mission. Our solution consists of • Readme • Figures S1 adjustments with respect to a global model expressed in spherical harmonics. The adjustments are • Figures S2 expressed as gridded gravity anomalies with a resolution of 1/6◦ by 1/6◦ (equivalent to that of a degree • Figures S3 and order 1080 model in spherical harmonics), covering a cap over the south pole with a radius of 40◦.The • Figures S4 • Figures S5 gravity anomalies have been estimated from a short-arc analysis using only Ka-band range-rate (KBRR) • Figures S6 data over the area of interest. -
Science Concept 5: Lunar Volcanism Provides a Window Into the Thermal and Compositional Evolution of the Moon
Science Concept 5: Lunar Volcanism Provides a Window into the Thermal and Compositional Evolution of the Moon Science Concept 5: Lunar volcanism provides a window into the thermal and compositional evolution of the Moon Science Goals: a. Determine the origin and variability of lunar basalts. b. Determine the age of the youngest and oldest mare basalts. c. Determine the compositional range and extent of lunar pyroclastic deposits. d. Determine the flux of lunar volcanism and its evolution through space and time. INTRODUCTION Features of Lunar Volcanism The most prominent volcanic features on the lunar surface are the low albedo mare regions, which cover approximately 17% of the lunar surface (Fig. 5.1). Mare regions are generally considered to be made up of flood basalts, which are the product of highly voluminous basaltic volcanism. On the Moon, such flood basalts typically fill topographically-low impact basins up to 2000 m below the global mean elevation (Wilhelms, 1987). The mare regions are asymmetrically distributed on the lunar surface and cover about 33% of the nearside and only ~3% of the far-side (Wilhelms, 1987). Other volcanic surface features include pyroclastic deposits, domes, and rilles. These features occur on a much smaller scale than the mare flood basalts, but are no less important in understanding lunar volcanism and the internal evolution of the Moon. Table 5.1 outlines different types of volcanic features and their interpreted formational processes. TABLE 5.1 Lunar Volcanic Features Volcanic Feature Interpreted Process -
10Great Features for Moon Watchers
Sinus Aestuum is a lava pond hemming the Imbrium debris. Mare Orientale is another of the Moon’s large impact basins, Beginning observing On its eastern edge, dark volcanic material erupted explosively and possibly the youngest. Lunar scientists think it formed 170 along a rille. Although this region at first appears featureless, million years after Mare Imbrium. And although “Mare Orien- observe it at several different lunar phases and you’ll see the tale” translates to “Eastern Sea,” in 1961, the International dark area grow more apparent as the Sun climbs higher. Astronomical Union changed the way astronomers denote great features for Occupying a region below and a bit left of the Moon’s dead lunar directions. The result is that Mare Orientale now sits on center, Mare Nubium lies far from many lunar showpiece sites. the Moon’s western limb. From Earth we never see most of it. Look for it as the dark region above magnificent Tycho Crater. When you observe the Cauchy Domes, you’ll be looking at Yet this small region, where lava plains meet highlands, con- shield volcanoes that erupted from lunar vents. The lava cooled Moon watchers tains a variety of interesting geologic features — impact craters, slowly, so it had a chance to spread and form gentle slopes. 10Our natural satellite offers plenty of targets you can spot through any size telescope. lava-flooded plains, tectonic faulting, and debris from distant In a geologic sense, our Moon is now quiet. The only events by Michael E. Bakich impacts — that are great for telescopic exploring. -
Mini-RF: Imaging Radars for Exploring the Lunar Poles
Mini-RF: Imaging Radars for Exploring the Lunar Poles Ben Bussey, Paul Spudis, Keith Raney, Helene Winters JHU/APL Stu Nozette, Chris Lichtenberg, Bill Marinelli NAWC 1 Mini-RF Organization, Science and Resource Evaluation Objectives • Mini-RF is a suite of radar instruments funded by NASA (SOMD & ESMD) and DoD. • Search for areas near the lunar poles that have the anomalous radar reflectivity signatures (high radar albedo and Circular Polarization Ratios) that differentiate volumetric water-ice deposits from more typical lunar surfaces • Map the morphology of permanently dark regions near the poles 2 Search for Ice • The case for water-ice can be resolved only if robust and repeatable data of the lunar polar regions support that conclusion. This rigorous standard can be met only by a dedicated polar-orbiting radar. • Mini-RF will use a unique hybrid polarity architecture to look for ice deposits • Transmit circular polarization (e.g. right-circular polarization RCP) • Receive coherent orthogonal polarizations • Derive Stokes parameters of the received signal • Use Stokes parameters to reconstruct and investigate the nature of the backscatter field. Distinguish between surface (roughness) and volume (ice) scattering 3 Top-level Radar Overview Parameter Chandrayaan-1 LRO • Frequency S-band S-band and X-band • Polarization Tx RCP Rx H & V • Scatterometry S-band (none) • Imager Regional maps Site-specific selections • Resolution (m/pixel) 75 75, 7.5 azimuth x 15 range • Looks 16 16 or 8 • Swath (km) 8 6 or 4 • Altitude (km) 100 50 • Incidence