Number of Near-Earth Objects and Formation of Lunar Craters Over the Last Billion Years
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
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. -
LCROSS (Lunar Crater Observation and Sensing Satellite) Observation Campaign: Strategies, Implementation, and Lessons Learned
Space Sci Rev DOI 10.1007/s11214-011-9759-y LCROSS (Lunar Crater Observation and Sensing Satellite) Observation Campaign: Strategies, Implementation, and Lessons Learned Jennifer L. Heldmann · Anthony Colaprete · Diane H. Wooden · Robert F. Ackermann · David D. Acton · Peter R. Backus · Vanessa Bailey · Jesse G. Ball · William C. Barott · Samantha K. Blair · Marc W. Buie · Shawn Callahan · Nancy J. Chanover · Young-Jun Choi · Al Conrad · Dolores M. Coulson · Kirk B. Crawford · Russell DeHart · Imke de Pater · Michael Disanti · James R. Forster · Reiko Furusho · Tetsuharu Fuse · Tom Geballe · J. Duane Gibson · David Goldstein · Stephen A. Gregory · David J. Gutierrez · Ryan T. Hamilton · Taiga Hamura · David E. Harker · Gerry R. Harp · Junichi Haruyama · Morag Hastie · Yutaka Hayano · Phillip Hinz · Peng K. Hong · Steven P. James · Toshihiko Kadono · Hideyo Kawakita · Michael S. Kelley · Daryl L. Kim · Kosuke Kurosawa · Duk-Hang Lee · Michael Long · Paul G. Lucey · Keith Marach · Anthony C. Matulonis · Richard M. McDermid · Russet McMillan · Charles Miller · Hong-Kyu Moon · Ryosuke Nakamura · Hirotomo Noda · Natsuko Okamura · Lawrence Ong · Dallan Porter · Jeffery J. Puschell · John T. Rayner · J. Jedadiah Rembold · Katherine C. Roth · Richard J. Rudy · Ray W. Russell · Eileen V. Ryan · William H. Ryan · Tomohiko Sekiguchi · Yasuhito Sekine · Mark A. Skinner · Mitsuru Sôma · Andrew W. Stephens · Alex Storrs · Robert M. Suggs · Seiji Sugita · Eon-Chang Sung · Naruhisa Takatoh · Jill C. Tarter · Scott M. Taylor · Hiroshi Terada · Chadwick J. Trujillo · Vidhya Vaitheeswaran · Faith Vilas · Brian D. Walls · Jun-ihi Watanabe · William J. Welch · Charles E. Woodward · Hong-Suh Yim · Eliot F. Young Received: 9 October 2010 / Accepted: 8 February 2011 © The Author(s) 2011. -
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. -
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. -
January 2019 Cardanus & Krafft
A PUBLICATION OF THE LUNAR SECTION OF THE A.L.P.O. EDITED BY: Wayne Bailey [email protected] 17 Autumn Lane, Sewell, NJ 08080 RECENT BACK ISSUES: http://moon.scopesandscapes.com/tlo_back.html FEATURE OF THE MONTH – JANUARY 2019 CARDANUS & KRAFFT Sketch and text by Robert H. Hays, Jr. - Worth, Illinois, USA September 24, 2018 04:40-05:04 UT, 15 cm refl, 170x, seeing 7/10, transparence 6/6. I drew these craters and vicinity on the night of Sept. 23/24, 2018. The moon was about 22 hours before full. This area is in far western Oceanus Procellarum, and was favorably placed for observation that night. Cardanus is the southern one of this pair and is of moderate depth. Krafft to the north is practically identical in size, and is perhaps slightly deeper. Neither crater has a central peak. Several small craters are near and within Krafft. The crater just outside the southeast rim of Krafft is Krafft E, and Krafft C is nearby within Krafft. The small pit to the west is Krafft K, and Krafft D is between Krafft and Cardanus. Krafft C, D and E are similar sized, but K is smaller than these. A triangular-shaped swelling protrudes from the north side of Krafft. The tiny pit, even smaller than Krafft K, east of Cardanus is Cardanus E. There is a dusky area along the southwest side of Cardanus. Two short dark strips in this area may be part of the broken ring Cardanus R as shown on the. Lunar Quadrant map. -
Planetary Surfaces
Chapter 4 PLANETARY SURFACES 4.1 The Absence of Bedrock A striking and obvious observation is that at full Moon, the lunar surface is bright from limb to limb, with only limited darkening toward the edges. Since this effect is not consistent with the intensity of light reflected from a smooth sphere, pre-Apollo observers concluded that the upper surface was porous on a centimeter scale and had the properties of dust. The thickness of the dust layer was a critical question for landing on the surface. The general view was that a layer a few meters thick of rubble and dust from the meteorite bombardment covered the surface. Alternative views called for kilometer thicknesses of fine dust, filling the maria. The unmanned missions, notably Surveyor, resolved questions about the nature and bearing strength of the surface. However, a somewhat surprising feature of the lunar surface was the completeness of the mantle or blanket of debris. Bedrock exposures are extremely rare, the occurrence in the wall of Hadley Rille (Fig. 6.6) being the only one which was observed closely during the Apollo missions. Fragments of rock excavated during meteorite impact are, of course, common, and provided both samples and evidence of co,mpetent rock layers at shallow levels in the mare basins. Freshly exposed surface material (e.g., bright rays from craters such as Tycho) darken with time due mainly to the production of glass during micro- meteorite impacts. Since some magnetic anomalies correlate with unusually bright regions, the solar wind bombardment (which is strongly deflected by the magnetic anomalies) may also be responsible for darkening the surface [I]. -
Feature of the Month – January 2016 Galilaei
A PUBLICATION OF THE LUNAR SECTION OF THE A.L.P.O. EDITED BY: Wayne Bailey [email protected] 17 Autumn Lane, Sewell, NJ 08080 RECENT BACK ISSUES: http://moon.scopesandscapes.com/tlo_back.html FEATURE OF THE MONTH – JANUARY 2016 GALILAEI Sketch and text by Robert H. Hays, Jr. - Worth, Illinois, USA October 26, 2015 03:32-03:58 UT, 15 cm refl, 170x, seeing 8-9/10 I sketched this crater and vicinity on the evening of Oct. 25/26, 2015 after the moon hid ZC 109. This was about 32 hours before full. Galilaei is a modest but very crisp crater in far western Oceanus Procellarum. It appears very symmetrical, but there is a faint strip of shadow protruding from its southern end. Galilaei A is the very similar but smaller crater north of Galilaei. The bright spot to the south is labeled Galilaei D on the Lunar Quadrant map. A tiny bit of shadow was glimpsed in this spot indicating a craterlet. Two more moderately bright spots are east of Galilaei. The western one of this pair showed a bit of shadow, much like Galilaei D, but the other one did not. Galilaei B is the shadow-filled crater to the west. This shadowing gave this crater a ring shape. This ring was thicker on its west side. Galilaei H is the small pit just west of B. A wide, low ridge extends to the southwest from Galilaei B, and a crisper peak is south of H. Galilaei B must be more recent than its attendant ridge since the crater's exterior shadow falls upon the ridge. -
37845R CS3 Book Hatfield's Diaries.Indd
“H.M.A.S. PERTH” 1939 -1941 From the diaries of P.O. George Hatfield Published in Sydney Australia in 2009 Publishing layout and Cover Design by George Hatfield Jnr. Printed by Springwood Printing Co. Faulconbridge NSW 2776 1 2 Foreword Of all the ships that have flown the ensign of the Royal Australian Navy, there has never been one quite like the first HMAS Perth, a cruiser of the Second World War. In her short life of just less than three years as an Australian warship she sailed all the world’s great oceans, from the icy wastes of the North Atlantic to the steamy heat of the Indian Ocean and the far blue horizons of the Pacific. She survived a hurricane in the Caribbean and months of Italian and German bombing in the Mediterranean. One bomb hit her and nearly sank her. She fought the Italians at the Battle of Matapan in March, 1941, which was the last great fleet action of the British Royal Navy, and she was present in June that year off Syria when the three Australian services - Army, RAN and RAAF - fought together for the first time. Eventually, she was sunk in a heroic battle against an overwhelming Japanese force in the Java Sea off Indonesia in 1942. Fast and powerful and modern for her times, Perth was a light cruiser of some 7,000 tonnes, with a main armament of eight 6- inch guns, and a top speed of about 34 knots. She had a crew of about 650 men, give or take, most of them young men in their twenties. -
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. -
Martian Crater Morphology
ANALYSIS OF THE DEPTH-DIAMETER RELATIONSHIP OF MARTIAN CRATERS A Capstone Experience Thesis Presented by Jared Howenstine Completion Date: May 2006 Approved By: Professor M. Darby Dyar, Astronomy Professor Christopher Condit, Geology Professor Judith Young, Astronomy Abstract Title: Analysis of the Depth-Diameter Relationship of Martian Craters Author: Jared Howenstine, Astronomy Approved By: Judith Young, Astronomy Approved By: M. Darby Dyar, Astronomy Approved By: Christopher Condit, Geology CE Type: Departmental Honors Project Using a gridded version of maritan topography with the computer program Gridview, this project studied the depth-diameter relationship of martian impact craters. The work encompasses 361 profiles of impacts with diameters larger than 15 kilometers and is a continuation of work that was started at the Lunar and Planetary Institute in Houston, Texas under the guidance of Dr. Walter S. Keifer. Using the most ‘pristine,’ or deepest craters in the data a depth-diameter relationship was determined: d = 0.610D 0.327 , where d is the depth of the crater and D is the diameter of the crater, both in kilometers. This relationship can then be used to estimate the theoretical depth of any impact radius, and therefore can be used to estimate the pristine shape of the crater. With a depth-diameter ratio for a particular crater, the measured depth can then be compared to this theoretical value and an estimate of the amount of material within the crater, or fill, can then be calculated. The data includes 140 named impact craters, 3 basins, and 218 other impacts. The named data encompasses all named impact structures of greater than 100 kilometers in diameter. -
General Disclaimer One Or More of the Following Statements May Affect
https://ntrs.nasa.gov/search.jsp?R=19710025504 2020-03-11T22:36:49+00:00Z View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by NASA Technical Reports Server General Disclaimer One or more of the Following Statements may affect this Document This document has been reproduced from the best copy furnished by the organizational source. It is being released in the interest of making available as much information as possible. This document may contain data, which exceeds the sheet parameters. It was furnished in this condition by the organizational source and is the best copy available. This document may contain tone-on-tone or color graphs, charts and/or pictures, which have been reproduced in black and white. This document is paginated as submitted by the original source. Portions of this document are not fully legible due to the historical nature of some of the material. However, it is the best reproduction available from the original submission. Produced by the NASA Center for Aerospace Information (CASI) 6 X t B ICC"m date: July 16, 1971 955 L'Enfant Plaza North, S. W Washington, D. C. 20024 to Distribution B71 07023 from. J. W. Head suhiecf Derivation of Topographic Feature Names in the Apollo 15 Landing Region - Case 340 ABSTRACT The topographic features in the region of the Apollo 15 landing site (Figure 1) are named for a number of philosophers, explorers and scientists (astronomers in particular) representing periods throughout recorded history. It is of particular interest that several of the individuals were responsible for specific discoveries, observations, or inventions which considerably advanced the study and under- standing of the moon (for instance, Hadley designed the first large reflecting telescope; Beer published classic maps and explanations of the moon's surface). -
DMAAC – February 1973
LUNAR TOPOGRAPHIC ORTHOPHOTOMAP (LTO) AND LUNAR ORTHOPHOTMAP (LO) SERIES (Published by DMATC) Lunar Topographic Orthophotmaps and Lunar Orthophotomaps Scale: 1:250,000 Projection: Transverse Mercator Sheet Size: 25.5”x 26.5” The Lunar Topographic Orthophotmaps and Lunar Orthophotomaps Series are the first comprehensive and continuous mapping to be accomplished from Apollo Mission 15-17 mapping photographs. This series is also the first major effort to apply recent advances in orthophotography to lunar mapping. Presently developed maps of this series were designed to support initial lunar scientific investigations primarily employing results of Apollo Mission 15-17 data. Individual maps of this series cover 4 degrees of lunar latitude and 5 degrees of lunar longitude consisting of 1/16 of the area of a 1:1,000,000 scale Lunar Astronautical Chart (LAC) (Section 4.2.1). Their apha-numeric identification (example – LTO38B1) consists of the designator LTO for topographic orthophoto editions or LO for orthophoto editions followed by the LAC number in which they fall, followed by an A, B, C or D designator defining the pertinent LAC quadrant and a 1, 2, 3, or 4 designator defining the specific sub-quadrant actually covered. The following designation (250) identifies the sheets as being at 1:250,000 scale. The LTO editions display 100-meter contours, 50-meter supplemental contours and spot elevations in a red overprint to the base, which is lithographed in black and white. LO editions are identical except that all relief information is omitted and selenographic graticule is restricted to border ticks, presenting an umencumbered view of lunar features imaged by the photographic base.