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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. -
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. -
Sky and Telescope
SkyandTelescope.com The Lunar 100 By Charles A. Wood Just about every telescope user is familiar with French comet hunter Charles Messier's catalog of fuzzy objects. Messier's 18th-century listing of 109 galaxies, clusters, and nebulae contains some of the largest, brightest, and most visually interesting deep-sky treasures visible from the Northern Hemisphere. Little wonder that observing all the M objects is regarded as a virtual rite of passage for amateur astronomers. But the night sky offers an object that is larger, brighter, and more visually captivating than anything on Messier's list: the Moon. Yet many backyard astronomers never go beyond the astro-tourist stage to acquire the knowledge and understanding necessary to really appreciate what they're looking at, and how magnificent and amazing it truly is. Perhaps this is because after they identify a few of the Moon's most conspicuous features, many amateurs don't know where Many Lunar 100 selections are plainly visible in this image of the full Moon, while others require to look next. a more detailed view, different illumination, or favorable libration. North is up. S&T: Gary The Lunar 100 list is an attempt to provide Moon lovers with Seronik something akin to what deep-sky observers enjoy with the Messier catalog: a selection of telescopic sights to ignite interest and enhance understanding. Presented here is a selection of the Moon's 100 most interesting regions, craters, basins, mountains, rilles, and domes. I challenge observers to find and observe them all and, more important, to consider what each feature tells us about lunar and Earth history. -
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. -
List of Targets for the Lunar II Observing Program (PDF File)
Task or Task Description or Target Name Wood's Rükl Target LUNAR # 100 Atlas Catalog (chart) Create a sketch/map of the visible lunar surface: 1 Observe a Full Moon and sketch a large-scale (prominent features) L-1 map depicting the nearside; disk of visible surface should be drawn 2 at L-1 3 least 5-inches in diameter. Sketch itself should be created only by L-1 observing the Moon, but maps or guidebooks may be used when labeling sketched features. Label all maria, prominent craters, and major rays by the crater name they originated from. (Counts as 3 observations (OBSV): #1, #2 & #3) Observe these targets; provide brief descriptions: 4 Alpetragius 55 5 Arago 35 6 Arago Alpha & Arago Beta L-32 35 7 Aristarchus Plateau L-18 18 8 Baco L-55 74 9 Bailly L-37 71 10 Beer, Beer Catena & Feuillée 21 11 Bullialdus, Bullialdus A & Bullialdus B 53 12 Cassini, Cassini A & Cassini B 12 13 Cauchy, Cauchy Omega & Cauchy Tau L-48 36 14 Censorinus 47 15 Crüger 50 16 Dorsae Lister & Smirnov (A.K.A. Serpentine Ridge) L-33 24 17 Grimaldi Basin outer and inner rings L-36 39, etc. 18 Hainzel, Hainzel A & Hainzel C 63 19 Hercules, Hercules G, Hercules E 14 20 Hesiodus A L-81 54, 64 21 Hortensius dome field L-65 30 22 Julius Caesar 34 23 Kies 53 24 Kies Pi L-60 53 25 Lacus Mortis 14 26 Linne 23 27 Lamont L-53 35 28 Mairan 9 29 Mare Australe L-56 76 30 Mare Cognitum 42, etc. -
0 Lunar and Planetary Institute Provided by the NASA Astrophysics Data System the ROLE of RIM SLUMPING in the MODIFICATION of LUNAR CRATER MORPHOMETRY
THE ROLE OF RIM SLUMPING 3N THE MODIFICATION OF LUNAR CRATER MOWHOMETRY Mark settlely2, and J. W. Head , (1) AF Cambridge Res. Labs (LWW) , Hanscom AFB, MA, (2) Dept. Geol. Sci., Brown Univ., Providence, RI 02912 The manner in which the depth of excavation of large scale lunar impacts increases with increasing crater diameter is unknown. Laboratory impact cra- tering experiments show that the depth/diameter ratio of an impact crater is at a maximum near the conclusion of the excavation stage of crater formation (5). This intermediate stage crater geometry is termed the initial crater cavity in this report. Subsequently, fallback will decrease crater depth, while dilation or "rebound" of basement materials and rim slumping will simul- taneously decrease crater depth and increase crater diameter. The net effect of these modification processes is to decrease the depthldiameter ratio of the initial crater cavity. Estimates of the depth of excavation of the initial cavities of large lunar craters are complicated by the pervasiveness of these modification pro- cesses. Several investigators have estimated the excavation depth of basin- sized impacts by extrapolating the nearly constant depthldiameter relationships observed for small fresh lunar craters (D <15 km) which do not appear to have experienced extensive modification (e. g. 4, 10). Such estimates assume that the depth of the initial cavity increases proportionally with increasing ca- vity diameter in such a manner that the depthldiameter ratio of the initial cavity is approximately the same for craters of all size. In this theory of proportional cavity growth the marked discontinuity in crater depthldiameter ratios observed at D=15 km is interpreted to be the result of an increase in the ability of modification processes to reshape the geometry of the initial crater cavity (e.g. -
Improved Method for Estimating Lunar Volcanic Dome Volumes
Improved Method for Estimating Lunar Volcanic Dome Volumes Using GIS Tools 1Washington University in St Louis and the McDonnell Center for the 2University of Western Ontario and the Centre for Planetary Space Sciences, 1 Brookings Drive, St Louis, MO 63130 1 2 1 Science and Exploration, 1151 Richmond St., London, Canada ([email protected]) Francis Baum , Michael Zanetti , Brad Jolliff N6A5B7 ([email protected]) Introduction: Volume estimates of lunar volcanic domes usually approximate their topography Gruithuisen Gamma LRO-NAC DTM on Shaded Relief Methodology Steps Gruithuisen Gamma LRO-NAC Image with basic three dimensional shapes, such as paraboloids or cones, so that a simple volume with azimuth lines & bounding rectangle equation can be used. For example, volume estimates of the Gruithuisen and Mairan domes Create contour lines: calculated in 2003 [1] treated each dome as a simple paraboloid. More recent volume estimates [2] To find the approximate base height and outline of a used a circular truncated cone approximation. However, more robust volume estimates and other volcanic dome, first contour lines were generated dimensional measurements can be calculated using Digital Terrain Models (DTMs) and various using LROC NAC/WAC DTM rasters [7] that covered Geographical Information System (GIS) tools. Here we discuss the tools and methods for the dome and surrounding area. Image and determining volumes of volcanic constructs on the Moon using DTMs, common ArcGIS [3] tools, topography interpretation at the discretion of the and the GeoEVE (Geologic Event Volume Estimator) tool [4]. We present the results from case geologist were also used. studies of these tools with respect to putative lunar silicic volcanic constructs [5]. -
What's Hot on the Moon Tonight?: the Ultimate Guide to Lunar Observing
What’s Hot on the Moon Tonight: The Ultimate Guide to Lunar Observing Copyright © 2015 Andrew Planck All rights reserved. No part of this book may be reproduced in any written, electronic, recording, or photocopying without written permission of the publisher or author. The exception would be in the case of brief quotations embodied in the critical articles or reviews and pages where permission is specifically granted by the publisher or author. Although every precaution has been taken to verify the accuracy of the information contained herein, the publisher and author assume no responsibility for any errors or omissions. No liability is assumed for damages that may result from the use of information contained within. Books may be purchased by contacting the publisher or author through the website below: AndrewPlanck.com Cover and Interior Design: Nick Zelinger (NZ Graphics) Publisher: MoonScape Publishing, LLC Editor: John Maling (Editing By John) Manuscript Consultant: Judith Briles (The Book Shepherd) ISBN: 978-0-9908769-0-8 Library of Congress Catalog Number: 2014918951 1) Science 2) Astronomy 3) Moon Dedicated to my wife, Susan and to my two daughters, Sarah and Stefanie Contents Foreword Acknowledgments How to Use this Guide Map of Major Seas Nightly Guide to Lunar Features DAYS 1 & 2 (T=79°-68° E) DAY 3 (T=59° E) Day 4 (T=45° E) Day 5 (T=24° E.) Day 6 (T=10° E) Day 7 (T=0°) Day 8 (T=12° W) Day 9 (T=21° W) Day 10 (T= 28° W) Day 11 (T=39° W) Day 12 (T=54° W) Day 13 (T=67° W) Day 14 (T=81° W) Day 15 and beyond Day 16 (T=72°) Day 17 (T=60°) FINAL THOUGHTS GLOSSARY Appendix A: Historical Notes Appendix B: Pronunciation Guide About the Author Foreword Andrew Planck first came to my attention when he submitted to Lunar Photo of the Day an image of the lunar crater Pitatus and a photo of a pie he had made. -
Upper Darby High School, 601 N Lansdowne Ave, Drexel Hill, PA
Basalt Thickness of Mare Tranquillitatis using Two Methods Upper Darby High School, 601 N Lansdowne Ave, Drexel Hill, PA Gutama Biru, Chris DeMott, Galen Farmer, Daniel Gordon, Isabel Hunt, Kenneth Lin, Thomas Nguyen, Zach Thornton, Vince Tran, Most Yeasmin PROBLEM ISOPACH MAPS The purpose of this experiment is to evaluate two methods of calculating basalt thickness in Mare Tranquillitatis. Figure 1 is the original isopach map used for reference. Figures 2 and 3 are isopach maps made using 3DField software. INTRODUCTION Lunar maria are large impact craters or basins that have been filled with basalt. While the Moon was still cooling, lava seeped into these basins through cracks, cooling to form the maria. This study compares two methods of determining the thickness of basalt in Mare Tranquillitatis: the Pre-Mare Crater Method and the Post- Figure 2. Pre-Mare Crater Isopach Mare Crater Method. The first method uses craters from before the mare was formed and the latter uses craters from after the mare was formed, as the names imply. Previous work ( De HONs map reference) has been conducted using these methods to Figure 1. Reference Map (DeHon 1974) calculate mare thickness; however the tools used to collect that data are outdated. The current study, conducted using data from the Lunar Reconnaissance Orbiter and Clementine camera, compares the two methods for determining mare thickness. The Pre-Mare Crater Method used craters that were formed inside the large impact basins before they filled with lava. By measuring the diameter of these craters, the original rim height can be estimated using a relationship defined by Pike (1974, 1977). -
RESEARCH Topographic Expressions of Lunar Graben
RESEARCH Topographic expressions of lunar graben Melanie B. Callihan* and Christian Klimczak STRUCTURAL GEOLOGY AND GEOMECHANICS GROUP, DEPARTMENT OF GEOLOGY, UNIVERSITY OF GEORGIA, ATHENS, GEORGIA 30602, USA ABSTRACT Graben, defined as landforms produced by normal faulting, have long been recognized on the Moon, but their map patterns, as well as topographic expressions, have not been studied systematically. The topography across graben and its along-strike variations reveal details about the growth of the normal faults forming the graben. Individual normal faults grow in length by the propagation of fault tips during slip events, which can also enlarge the displacement along the fault plane. Displacement and length accumulate and grow larger over time with more slip events, fault interaction, and linkage. We measured fault lengths and vertical offsets and then calculated the displacement for lunar graben using data from the camera and laser altimeter onboard the Lunar Reconnaissance Orbiter. Our study systematically investigated 14 graben systems across the lunar surface. Graben lengths were found to range from ~43 to 453 km, and displacements ranged from ~127 to 1115 m. These displacements were plotted against graben fault length to produce slip distributions, which revealed growth patterns involving mechanical interaction and fault linkage. Displacement-to-length scaling was used to further study the evolu- tion of graben-bounding normal faults. We observed a sublinear growth pattern for lunar graben-bounding normal faults, consistent with growth of faults via segment linkage, where different stages of linkage are present on the lunar surface. Lunar graben-bounding faults show higher scaling ratios than previously estimated, likely due to variations in host-rock properties and mechanical stratigraphy. -
Thumbnail Index
Thumbnail Index The following five pages depict each plate in the book and provide the following information about it: • Longitude and latitude of the main feature shown. • Sun’s angle (SE), ranging from 1°, with grazing illumination and long shadows, up to 72° for nearly full Moon conditions with the Sun almost overhead. • The elevation or height (H) in kilometers of the spacecraft above the surface when the image was acquired, from 21 to 116 km. • The time of acquisition in this sequence: year, month, day, hour, and minute in Universal Time. 1. Gauss 2. Cleomedes 3. Yerkes 4. Proclus 5. Mare Marginis 79°E, 36°N SE=30° H=65km 2009.05.29. 05:15 56°E, 24°N SE=28° H=100km 2008.12.03. 09:02 52°E, 15°N SE=34° H=72km 2009.05.31. 06:07 48°E, 17°N SE=59° H=45km 2009.05.04. 06:40 87°E, 14°N SE=7° H=60km 2009.01.10. 22:29 6. Mare Smythii 7. Taruntius 8. Mare Fecunditatis 9. Langrenus 10. Petavius 86°E, 3°S SE=19° H=58km 2009.01.11. 00:28 47°E, 6°N SE=33° H=72km 2009.05.31. 15:27 50°E, 7°S SE=10° H=64km 2009.01.13. 19:40 60°E, 11°S SE=24° H=95km 2008.06.08. 08:10 61°E, 23°S SE=9° H=65km 2009.01.12. 22:42 11.Humboldt 12. Furnerius 13. Stevinus 14. Rheita Valley 15. Kaguya impact point 80°E, 27°S SE=42° H=105km 2008.05.10. -
LECTURES on GRAVITATION and RELATIVITY Goddard Institute For
LECTURES ON GRAVITATION AND RELATIVITY Goddard Institute for Space Studies New York, New York Volume II w THE SIGNIFICANCE FOR THE SOLAR SYSTEM OF TIME VARYING GRAVITATION N88- 14305 Lecture VIII R. H. Dicke Princeton University Seminar on Gravitation and Relativity, NASA Goddard Space \Ylight Center, Institute for Space Studies, New York, N.Y.; \edited by H. Y. Chiu and W. F. Hoffmann. I ! l Preface These notes were taken from a series of seminars on Gravitation and Relativity presented at the Institute for Space Studies, NASA Goddard Space Flight Center during the academic year 1961-1962. Professor R. H. Dicke of Princeton University organized the series as an introduction to the subject for non-experts, emphasizing the observable implications of the theory and the potential contribution the space sciences may make towards a better understanding of general relativity. The approach has been conceptual rather than formal. For this reason, this record does not include a complete mathematical development of the subject, but, we hope, does contain sufficient mathematics to elaborate on the conceptual discussions. The notes were prepared with a minimum amount of editing from a transcript made from recordings of the lectures. The speakers have not had the opportunity to read and correct the final manuscript. Hence, we accept responsi- bility for errors and omissions. H. Y. Chiu W. F. Hoffmann I In my last lecture, I discussed a number of general features of gravitation theory. Two of these features furnish the starting point for this lecture. i) The requirements that a theory of gravitation be expressed in generally covariant equations and that inertial and gravitational forces both be obtained from a single invariant lead us naturally to represent gravitational effects by a tensor field.