Crater Populations on Lunar Rocks
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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. -
No. 40. the System of Lunar Craters, Quadrant Ii Alice P
NO. 40. THE SYSTEM OF LUNAR CRATERS, QUADRANT II by D. W. G. ARTHUR, ALICE P. AGNIERAY, RUTH A. HORVATH ,tl l C.A. WOOD AND C. R. CHAPMAN \_9 (_ /_) March 14, 1964 ABSTRACT The designation, diameter, position, central-peak information, and state of completeness arc listed for each discernible crater in the second lunar quadrant with a diameter exceeding 3.5 km. The catalog contains more than 2,000 items and is illustrated by a map in 11 sections. his Communication is the second part of The However, since we also have suppressed many Greek System of Lunar Craters, which is a catalog in letters used by these authorities, there was need for four parts of all craters recognizable with reasonable some care in the incorporation of new letters to certainty on photographs and having diameters avoid confusion. Accordingly, the Greek letters greater than 3.5 kilometers. Thus it is a continua- added by us are always different from those that tion of Comm. LPL No. 30 of September 1963. The have been suppressed. Observers who wish may use format is the same except for some minor changes the omitted symbols of Blagg and Miiller without to improve clarity and legibility. The information in fear of ambiguity. the text of Comm. LPL No. 30 therefore applies to The photographic coverage of the second quad- this Communication also. rant is by no means uniform in quality, and certain Some of the minor changes mentioned above phases are not well represented. Thus for small cra- have been introduced because of the particular ters in certain longitudes there are no good determi- nature of the second lunar quadrant, most of which nations of the diameters, and our values are little is covered by the dark areas Mare Imbrium and better than rough estimates. -
Secondary Craters on Europa and Implications for Cratered Surfaces
Vol 437|20 October 2005|doi:10.1038/nature04069 LETTERS Secondary craters on Europa and implications for cratered surfaces Edward B. Bierhaus1, Clark R. Chapman2 & William J. Merline2 For several decades, most planetary researchers have regarded the craters were typically not spatially random, but instead appeared in impact crater populations on solid-surfaced planets and smaller clumps and clusters16 even at distances far (several hundred kilo- bodies as predominantly reflecting the direct (‘primary’) impacts metres) from the nearest large primary crater. This clustered spatial of asteroids and comets1. Estimates of the relative and absolute distribution contrasts with primary impacts, which are spatially ages of geological units on these objects have been based on this random. The low spatial density and unusual non-random spatial assumption2. Here we present an analysis of the comparatively distribution of Europa’s small craters enabled us to achieve what has sparse crater population on Jupiter’s icy moon Europa and suggest been previously difficult, namely unambiguous identification and that this assumption is incorrect for small craters. We find that quantification of the contribution of distant secondary craters to the ‘secondaries’ (craters formed by material ejected from large total crater SFD. This, in turn, allows us to re-examine the overall primary impact craters) comprise about 95 per cent of the small crater age-dating methodology. We discuss the specifics of the craters (diameters less than 1 km) on Europa. We therefore con- Europa data first. clude that large primary impacts into a solid surface (for example, We measured more than 17,000 craters in 87 low-compression, ice or rock) produce far more secondaries than previously low-sun, high-resolution Europa images (scales ,60 m pixel21), believed, implying that the small crater populations on the which cover nine regions totalling 0.2% of Europa’s surface (a much Moon, Mars and other large bodies must be dominated by larger percentage of Europa has been imaged at lower resolutions), secondaries. -
WILKINSON COLLEGE of Arts, Humanities, and Social Sciences
2014 – 2015 WILKINSON COLLEGE of Arts, Humanities, and Social Sciences ANNUAL REPORT 2 Table of Contents Opening Statement ..........................................................................................................................................2-3 International Reach ........................................................................................................................................ 4-5 CRASsH and BURN .......................................................................................................................................6-7 Collections in Wilkinson ..................................................................................................................................8 Creative Industries .............................................................................................................................................9 Arts and Humanities................ ...................................................................................................................10-25 Art ....................................................................................................................................................10-11 English .............................................................................................................................................12-13 World Languages & Cultures .......................................................................................................14-15 Religious Studies ............................................................................................................................16-17 -
Board Certified Fellows
AMERICAN BOARD OF MEDICOLEGAL DEATH INVESTIGATORS Certificant Directory As of September 30, 2021 BOARD CERTIFIED FELLOWS Addison, Krysten Leigh (Inactive) BC2286 Allmon, James L. BC855 Travis County Medical Examiner's Office Sangamon County Coroner's Office 1213 Sabine Street 200 South 9th, Room 203 PO Box 1748 Springfield, IL 62701 Austin, TX 78767 Amini, Navid BC2281 Appleberry, Sherronda BC1721 Olmsted Medical Examiner's Office Adams and Broomfield County Office of the Coroner 200 1st Street Southwest 330 North 19th Avenue Rochester, MN 55905 Brighton, CO 80601 Applegate, MD, David T. BC1829 Archer, Meredith D. BC1036 Union County Coroner's Office Mohave County Medical Examiner 128 South Main Street 1145 Aviation Drive Unit A Marysville, OH 43040 Lake Havasu, AZ 86404 Bailey, Ted E. (Inactive) BC229 Bailey, Sanisha Renee BC1754 Gwinnett County Medical Examiner's Office Virginia Office of the Chief Medical Examiner 320 Hurricane Shoals Road, NE Central District Lawrenceville, GA 30046 400 East Jackson Street Richmond, VA 23219 Balacki, Alexander J BC1513 Banks, Elsie-Kay BC3039 Montgomery County Coroner's Office Maine Office of the Chief Medical Examiner 1430 Dekalb Street 30 Hospital Street PO Box 311 Augusta, ME 04333 Norristown, PA 19404 Bautista, Ian BC2185 Bayer, Lindsey A. BC875 New York City Office of Chief Medical Examiner District 5 and 24 Medical Examiner Office 421 East 26th Street 809 Pine Street New York, NY 10016 Leesburg, FL 34756 Beck, Shari L BC327 Beckham, Phinon Phillips BC2305 Sedgwick Co Reg. Forensic Science Center Virginia Office of the Chief Medical Examiner 1109 N. Minneapolis Northern District Wichita, KS 67214 10850 Pyramid Place, Suite 121 Manassas, VA 20110 Bednar Keefe, Gale M. -
Issue 112, November 2007
Return to the Moon: A New Perspective RETURN TO THE MOON: A NEW PERSPECTIVE Sometimes history does repeat itself. Just as 40 years ago as the United States prepared to land the fi rst humans on the Moon, several nations are now beginning their own precursor robotic exploration of the Moon with an eye to the future. Japan and China have both launched advanced orbital mapping missions to the Moon in the past three months, with India and the United States to follow in 2008. Both Asian missions are successfully in orbit and conducting instrument checkouts and calibrations before full-scale mapping begins. They bring a wide variety of scientifi c investigations across a broad reach of the electromagnetic spectrum to bear on our nearest neighbor, hoping to unlock its secrets. At stake are knowledge of lunar resources, including whether ice exists at the poles, and a clearer understanding of the origins and earliest history of the Moon. The United States has a strong interest in returning to the Moon with astronauts, and the fl eet of orbiting robots, including Lunar Reconaissance Orbiter to launch next summer, will aid in guiding those explorers to the right location. To further aid those who are planning those future expeditions, several groups are digging into the old Apollo records, including planning charts, reports, and images. Many of these resources are now Lonline, including at the Lunar and Planetary Institute, available for all lunar afi cionados. The next decade promises to be an exciting one for lunar research. With the new missions underway, we feature in this issue several related reports on these new initiatives and the restoration of the historic records and archives. -
Volcano Collapse Promoted by Hydrothermal Alteration and Edifice
Volcano collapse promoted by hydrothermal alteration and edifice shape, Mount Rainier, Washington Mark E. Reid* Thomas W. Sisson U.S. Geological Survey, 345 Middlefield Road, MS 910, Menlo Park, California 94025, USA Dianne L. Brien ABSTRACT FLANK COLLAPSES AT MOUNT RAINIER Catastrophic collapses of steep volcano flanks threaten many At Mount Rainier, some volcanic debris flows or lahars began as populated regions, and understanding factors that promote collapse fluid-saturated flank collapses (large landslides), whereas others were could save lives and property. Large collapses of hydrothermally al- likely triggered by pyroclastic flows entraining snow and ice, glacial tered parts of Mount Rainier have generated far-traveled debris flows; outburst floods, or torrential rains. Hydrothermally derived clay min- future flows would threaten densely populated parts of the Puget erals are abundant in some of the most widespread lahar deposits, in- Sound region. We evaluate edifice collapse hazards at Mount Rainier cluding the massive ;3.8 km3 Osceola Mudflow of 5600 yr ago (Cran- using a new three-dimensional slope stability method incorporating dell and Waldron, 1956; Vallance and Scott, 1997), the ;0.2 km3 detailed geologic mapping and subsurface geophysical imaging to de- Round Pass mudflow of ;2600 yr ago, and the ;0.26 km3 Electron termine distributions of strong (fresh) and weak (altered) rock. Quan- mudflow of ;500 yr ago (Scott et al., 1995). This association is evi- titative three-dimensional slope stability calculations reveal that size- dence that weakening of edifice rocks by acid sulfate-argillic hydro- able flank collapse (.0.1 km3)ispromotedbyvoluminous,weak, thermal alteration promoted flank collapse (Crandell, 1971; Scott et al., hydrothermally altered rock situated high on steep slopes. -
Ages of Large Lunar Impact Craters and Implications for Bombardment During the Moon’S Middle Age ⇑ Michelle R
Icarus 225 (2013) 325–341 Contents lists available at SciVerse ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Ages of large lunar impact craters and implications for bombardment during the Moon’s middle age ⇑ Michelle R. Kirchoff , Clark R. Chapman, Simone Marchi, Kristen M. Curtis, Brian Enke, William F. Bottke Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302, United States article info abstract Article history: Standard lunar chronologies, based on combining lunar sample radiometric ages with impact crater den- Received 20 October 2012 sities of inferred associated units, have lately been questioned about the robustness of their interpreta- Revised 28 February 2013 tions of the temporal dependance of the lunar impact flux. In particular, there has been increasing focus Accepted 10 March 2013 on the ‘‘middle age’’ of lunar bombardment, from the end of the Late Heavy Bombardment (3.8 Ga) until Available online 1 April 2013 comparatively recent times (1 Ga). To gain a better understanding of impact flux in this time period, we determined and analyzed the cratering ages of selected terrains on the Moon. We required distinct ter- Keywords: rains with random locations and areas large enough to achieve good statistics for the small, superposed Moon, Surface crater size–frequency distributions to be compiled. Therefore, we selected 40 lunar craters with diameter Cratering Impact processes 90 km and determined the model ages of their floors by measuring the density of superposed craters using the Lunar Reconnaissance Orbiter Wide Angle Camera mosaic. Absolute model ages were computed using the Model Production Function of Marchi et al. -
Detection of Small Lunar Secondary Craters in Circular Polarization Ratio Radar Images Kassandra S
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 115, E06008, doi:10.1029/2009JE003491, 2010 Click Here for Full Article Detection of small lunar secondary craters in circular polarization ratio radar images Kassandra S. Wells,1 Donald B. Campbell,1 Bruce A. Campbell,2 and Lynn M. Carter2 Received 20 August 2009; revised 4 February 2010; accepted 22 February 2010; published 17 June 2010. [1] The identification of small (D < a few kilometers) secondary craters and their global distributions are of critical importance to improving our knowledge of surface ages in the solar system. We investigate a technique by which small, distal secondary craters can be discerned from the surrounding primary population of equivalent size based on asymmetries in their ejecta blankets. The asymmetric ejecta blankets are visible in radar circular polarization ratio (CPR) but not as optical albedo features. Measurements with our new technique reveal 94 secondary craters on the Newton and Newton‐A crater floors near the lunar south pole. These regions are not in an obvious optical ray, but the orientation of asymmetric secondary ejecta blankets suggests that they represent an extension of the Tycho crater ray that crosses Clavius crater. Including the secondary craters at Newton and Newton‐A skews the terrain age inferred by crater counts. It is reduced by few percentages by their removal, from 3.8 to 3.75 Gyr at Newton‐A. Because “hidden rays” like that identified here may also occur beyond the edges of other optically bright lunar crater rays, we assess the effect that similar but hypothetical populations would have on lunar terrains of various ages. -
Chapman University Choir & Women's Choir in Concert
Chapman University Chapman University Digital Commons Printed Performance Programs (PDF Format) Music Performances 10-26-2012 Chapman University Choir & Women's Choir in Concert Chapman University Choir Chapman University Women's Choir Follow this and additional works at: http://digitalcommons.chapman.edu/music_programs Recommended Citation Chapman University Choir and Chapman University Women's Choir, "Chapman University Choir & Women's Choir in Concert" (2012). Printed Performance Programs (PDF Format). Paper 752. http://digitalcommons.chapman.edu/music_programs/752 This Choral Performance is brought to you for free and open access by the Music Performances at Chapman University Digital Commons. It has been accepted for inclusion in Printed Performance Programs (PDF Format) by an authorized administrator of Chapman University Digital Commons. For more information, please contact [email protected]. Chapman University Choir & Women's Choir in Concert October 26, 2012 I faU 2012 · •mCHAPMAN --UNIVERSITY COLLEGE OF PERFORMING ARTS CHAPMAN UNIVERSITY FALL 2012 calendar highlights september Conservatory Music September 27-29, October 4-6 of Company, Book by George Furth, Music and Lyrics by Stephen Sondheim presents Directed by Todd Nielsen, Music Direction by Bill Brown october October 19-21 Opera Chapman presents "2012: An Opera Odyssey - The Journey Continues" Peter Atherton, Artistic Director, Carol Neblett, Associate Director, David Alt, Assistant Director October 26 Chapman University Choir and Women's Choir in Concert Stephen Coker -
Appendix A. Reference List
Ice Age Floods Study of Alternatives Appendix A—Reference List appendix a REFERENCE LIST Alexander, David. Natural Disasters. NY: Chapman and Hall, 1993. Allen, John Eliot. Magnificent Gateway. Forest Grove, Oregon, 1979. —. Burns, Marjorie, and Samuel C. Sargent. Cataclysms on the Columbia. Portland, OR: Timber Press, 1986. Allison, I. S. “New Version of the Spokane Flood,” in Fryxell, Roald and Cook, Earl F. eds., A Field Guide to the Loess Deposits and Channeled Scablands of the Palouse Area, Eastern Washington: Pullman, WA: Washington State University, Division Archaeology Geochronology, Lab Anthropology, 1964. —. “Flint’s Fill Hypothesis for Channeled Scabland.” Journal of Geology, v.49, 1941. Alt, David, and Donald W. Hyndman. Roadside Geology of Oregon. Missoula, MT: Mountain Press Publishing Company, 1978. —. and Donald W. Hyndman. Roadside Geology of Washington. Missoula, MT: Mountain Press Publishing Company, 1984. —. and Donald W. Hyndman. Roadside Geology of Montana. Missoula, MT: Mountain Press Publishing Company, 1986. —. and Donald W. Hyndman. Roadside Geology of Idaho. Missoula, MT: Mountain Press Publishing Company, 1989. —. and Donald W. Hyndman. Northwest Exposures: A Geologic Story of the Northwest. Missoula, MT: Mountain Press Publishing Company, 1995. Bacon, Charles R. “Mount Mazama and Crater Lake Caldera, Oregon,” in Hill, M. L., (ed.), Cordilleran Section of the Geological Society of America, Centennial Field Guide Volume 1. The Geological Society of America, 1987. A-1 F LO E OD G S A E C I Appendix A—Reference List Bailey, R. A., C. D. Miller, and K. Sieh. “Quaternary Volcanism of Long —. “Quaternary Geology of the Channeled Scabland and Adjacent Valley Caldera and Mono-Inyo Craters, Eastern California.” Areas,” in V. -
Meteorite Impacts, Earth, and the Solar System
Traces of Catastrophe A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures Bevan M. French Research Collaborator Department of Mineral Sciences, MRC-119 Smithsonian Institution Washington DC 20560 LPI Contribution No. 954 i Copyright © 1998 by LUNAR AND PLANETARY INSTITUTE The Institute is operated by the Universities Space Research Association under Contract No. NASW-4574 with the National Aeronautics and Space Administration. Material in this volume may be copied without restraint for library, abstract service, education, or personal research purposes; however, republication of any portion thereof requires the written permission of the Insti- tute as well as the appropriate acknowledgment of this publication. Figures 3.1, 3.2, and 3.5 used by permission of the publisher, Oxford University Press, Inc. Figures 3.13, 4.16, 4.28, 4.32, and 4.33 used by permission of the publisher, Springer-Verlag. Figure 4.25 used by permission of the publisher, Yale University. Figure 5.1 used by permission of the publisher, Geological Society of America. See individual captions for reference citations. This volume may be cited as French B. M. (1998) Traces of Catastrophe:A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures. LPI Contribution No. 954, Lunar and Planetary Institute, Houston. 120 pp. This volume is distributed by ORDER DEPARTMENT Lunar and Planetary Institute 3600 Bay Area Boulevard Houston TX 77058-1113, USA Phone:281-486-2172 Fax:281-486-2186 E-mail:[email protected] Mail order requestors will be invoiced for the cost of shipping and handling. Cover Art.“One Minute After the End of the Cretaceous.” This artist’s view shows the ancestral Gulf of Mexico near the present Yucatán peninsula as it was 65 m.y.