Mini-Rf Radar Observations of Polar Craters: Are They Rough, Smooth, Or Icy?
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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. -
October 2006
OCTOBER 2 0 0 6 �������������� http://www.universetoday.com �������������� TAMMY PLOTNER WITH JEFF BARBOUR 283 SUNDAY, OCTOBER 1 In 1897, the world’s largest refractor (40”) debuted at the University of Chica- go’s Yerkes Observatory. Also today in 1958, NASA was established by an act of Congress. More? In 1962, the 300-foot radio telescope of the National Ra- dio Astronomy Observatory (NRAO) went live at Green Bank, West Virginia. It held place as the world’s second largest radio scope until it collapsed in 1988. Tonight let’s visit with an old lunar favorite. Easily seen in binoculars, the hexagonal walled plain of Albategnius ap- pears near the terminator about one-third the way north of the south limb. Look north of Albategnius for even larger and more ancient Hipparchus giving an almost “figure 8” view in binoculars. Between Hipparchus and Albategnius to the east are mid-sized craters Halley and Hind. Note the curious ALBATEGNIUS AND HIPPARCHUS ON THE relationship between impact crater Klein on Albategnius’ southwestern wall and TERMINATOR CREDIT: ROGER WARNER that of crater Horrocks on the northeastern wall of Hipparchus. Now let’s power up and “crater hop”... Just northwest of Hipparchus’ wall are the beginnings of the Sinus Medii area. Look for the deep imprint of Seeliger - named for a Dutch astronomer. Due north of Hipparchus is Rhaeticus, and here’s where things really get interesting. If the terminator has progressed far enough, you might spot tiny Blagg and Bruce to its west, the rough location of the Surveyor 4 and Surveyor 6 landing area. -
Glossary of Lunar Terminology
Glossary of Lunar Terminology albedo A measure of the reflectivity of the Moon's gabbro A coarse crystalline rock, often found in the visible surface. The Moon's albedo averages 0.07, which lunar highlands, containing plagioclase and pyroxene. means that its surface reflects, on average, 7% of the Anorthositic gabbros contain 65-78% calcium feldspar. light falling on it. gardening The process by which the Moon's surface is anorthosite A coarse-grained rock, largely composed of mixed with deeper layers, mainly as a result of meteor calcium feldspar, common on the Moon. itic bombardment. basalt A type of fine-grained volcanic rock containing ghost crater (ruined crater) The faint outline that remains the minerals pyroxene and plagioclase (calcium of a lunar crater that has been largely erased by some feldspar). Mare basalts are rich in iron and titanium, later action, usually lava flooding. while highland basalts are high in aluminum. glacis A gently sloping bank; an old term for the outer breccia A rock composed of a matrix oflarger, angular slope of a crater's walls. stony fragments and a finer, binding component. graben A sunken area between faults. caldera A type of volcanic crater formed primarily by a highlands The Moon's lighter-colored regions, which sinking of its floor rather than by the ejection of lava. are higher than their surroundings and thus not central peak A mountainous landform at or near the covered by dark lavas. Most highland features are the center of certain lunar craters, possibly formed by an rims or central peaks of impact sites. -
IWLOP Logbook
Isabel Williamson Lunar Observing Logbook The certificate applicant must use this logbook (or an equivant means) to qualify. Enter the date, time, and other details for each observation as indicated. The R (required) objectives are mandatory; the C (challenge) objectives are optional. Sketch drawings are also optional, but encouraged. Use the small template provided, or the larger one found on p. 84 of this logbook. PART 1 – Introducing the Moon A – Lunar Phases and Orbital Motion R 1 – Enter in the notes section the date and time for each phase observed. R 2 – Date _________________ Time__________________ R 3 – Date _________________ Time__________________ Date _________________ Time__________________ Notes _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ B – Major Basins (Maria) & Pickering Unaided Eye Scale R 1 – Date __________________ Time__________________ C 1 – Date __________________ Time__________________ C 2 – Date __________________ Time__________________ Notes (see p. 81 of this logbook for optional Pickering Unaided Eye Scale) __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ C – Ray System Extent R 1 – Date ___________________ Time_________________ C 1 – Date ___________________ Time_________________ Notes (see p. 82 of this -
GRAIL Gravity Observations of the Transition from Complex Crater to Peak-Ring Basin on the Moon: Implications for Crustal Structure and Impact Basin Formation
Icarus 292 (2017) 54–73 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus GRAIL gravity observations of the transition from complex crater to peak-ring basin on the Moon: Implications for crustal structure and impact basin formation ∗ David M.H. Baker a,b, , James W. Head a, Roger J. Phillips c, Gregory A. Neumann b, Carver J. Bierson d, David E. Smith e, Maria T. Zuber e a Department of Geological Sciences, Brown University, Providence, RI 02912, USA b NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA c Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130, USA d Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064, USA e Department of Earth, Atmospheric and Planetary Sciences, MIT, Cambridge, MA 02139, USA a r t i c l e i n f o a b s t r a c t Article history: High-resolution gravity data from the Gravity Recovery and Interior Laboratory (GRAIL) mission provide Received 14 September 2016 the opportunity to analyze the detailed gravity and crustal structure of impact features in the morpho- Revised 1 March 2017 logical transition from complex craters to peak-ring basins on the Moon. We calculate average radial Accepted 21 March 2017 profiles of free-air anomalies and Bouguer anomalies for peak-ring basins, protobasins, and the largest Available online 22 March 2017 complex craters. Complex craters and protobasins have free-air anomalies that are positively correlated with surface topography, unlike the prominent lunar mascons (positive free-air anomalies in areas of low elevation) associated with large basins. -
Lunar Club Observations
Guys & Gals, Here, belatedly, is my Christmas present to you. I couldn’t buy each of you a lunar map, so I did the next best thing. Below this letter you’ll find a guide for observing each of the 100 lunar features on the A. L.’s Lunar Club observing list. My guide tells you what the features are, where they are located, what instrument (naked eyes, binoculars or telescope) will give you the best view of them and what you can expect to see when you find them. It may or may not look like it, but this project involved a massive amount of work. In preparing it, I relied heavily on three resources: *The lunar map I used to determine which quadrant of the Moon each feature resides in is the laminated Sky & Telescope Lunar Map – specifically, the one that shows the Moon as we see it naked-eye or in binoculars. (S&T also sells one with the features reversed to match the view in a refracting telescope for the same price.); and *The text consists of information from (a) my own observing notes and (b) material in Ernest Cherrington’s Exploring the Moon Through Binoculars and Small Telescopes. Both the map and Cherrington’s book were door prizes at our Dec. Christmas party. My goal, of course, is to get you interested in learning more about our nearest neighbor in space. The Moon is a fascinating and lovely place, and one that all too often is overlooked by amateur astronomers. But of all the objects in the night sky, the Moon is the most accessible and easiest to observe. -
Guide to Observing the Moon
Your guide to The Moonby Robert Burnham A supplement to 618128 Astronomy magazine 4 days after New Moon south is up to match the view in a the crescent moon telescope, and east lies to the left. f you look into the western sky a few evenings after New Moon, you’ll spot a bright crescent I glowing in the twilight. The Moon is nearly everyone’s first sight with a telescope, and there’s no better time to start watching it than early in the lunar cycle, which begins every month when the Moon passes between the Sun and Earth. Langrenus Each evening thereafter, as the Moon makes its orbit around Earth, the part of it that’s lit by the Sun grows larger. If you look closely at the crescent Mare Fecunditatis zona I Moon, you can see the unlit part of it glows with a r a ghostly, soft radiance. This is “the old Moon in the L/U. p New Moon’s arms,” and the light comes from sun- /L tlas Messier Messier A a light reflecting off the land, clouds, and oceans of unar Earth. Just as we experience moonlight, the Moon l experiences earthlight. (Earthlight is much brighter, however.) At this point in the lunar cycle, the illuminated Consolidated portion of the Moon is fairly small. Nonetheless, “COMET TAILS” EXTENDING from Messier and Messier A resulted from a two lunar “seas” are visible: Mare Crisium and nearly horizontal impact by a meteorite traveling westward. The big crater Mare Fecunditatis. Both are flat expanses of dark Langrenus (82 miles across) is rich in telescopic features to explore at medium lava whose appearance led early telescopic observ- and high magnification: wall terraces, central peaks, and rays. -
May 2021 the Lunar Observer by the Numbers
A Publication of the Lunar Section of ALPO Edited by David Teske: [email protected] 2162 Enon Road, Louisville, Mississippi, USA Back issues: http://www.alpo-astronomy.org/ Online readers, May 2021 click on images In This Issue for hyperlinks Observations Received 2 By the Numbers 4 Stöfler and Maurolycus Region, H. Eskildsen 5 North-ish, R. Hill 6 Medii to Delaunay and a Concentric Crater, H. Eskildsen 7 The Greatest Crater? R. Hill 8 The Glorious Rupes Cauchy, A. Anunziato 9 The Western Chain on the Eastern Moon, H. Eskildsen 10 A Scarp by any Other Name, R. Hill 11 Mädlers Bright Streak, Ray or Elevation? A. Anunziato 12 Caucasus to Mare Vaporum, Close-Up Images of Aristillus, Autolycus and Putredinis Domes, H. Eskildsen 15 Images of Crater Schickard, J. D. Sabia 17 Another Trio, R. Hill 18 Mare Vaporum to Sinus Medii and Associated Domes, H. Eskildsen 19 Focus-On: The Lunar 100 Features 61-70, J. Hubbell 21 Lunar 61-70, A. Anunziato 24 Mösting A, R. H. Hays, Jr. 26 Hortensius and Domes, R. H. Hays, Jr. 53 Mare Humboldtianum, the Other Multi-Ring Lunar Basin, D. Teske 75 Recent Lunar Topographic Studies 81 Lunar Geologic Change Detection Program, T. Cook 100 ALPO 2021 Conference News 108 Lunar Calendar May 2021 110 An Invitation to Join ALPO 110 Submission Through the ALPO Image Achieve 111 When Submitting Observations to the ALPO Lunar Section 112 Call For Observations Focus-On 112 Focus-On Announcement 113 Key to Images in this Issue 114 The May issue of The Lunar Observer features a number of interesting articles by Howard Eskildsen, Rob- ert H. -
The Nature of the Typical Lunar Mountain Walled Plains
THE NATURE OF THE TYPICAL LUNAR MOUNTAIN WALLED PLAINS Dinsmore Alter Griffith Observatory, Los Angeles, California This is the third of a series of papers concerning the evolution of the present surface of the moon.1 In a study of this nature, it is necessary to refer to many features by the proper names used by selenographers. Unfortunately, however, these names often are mystifying to a reader. In the second paper of the series, published in the February 1956 issue of these Publications, two pages were devoted to a photographic map of the moon from which χ and y coordinates can be read easily. Table I lists the names and coordinates from that map of all the objects mentioned in this paper. In Table II are listed the lunar photographs repro- duced in the present paper. TABLE I Coordinates of Features Mentioned in This Paper Object χ y Object χ y Albategnius 65 84 Mare Nubium 85 94 Aliacensis 65 105 Mare Serenitatis .. 52 42 Archimedes 75 39 Pitatus 83 103 Blancanus 77 126 Plato 76 18 Catharina 44 93 Posidonius 42 36 Clavius 75 124 Ptolemaeus 74 82 Gassendi 108 90 Pur bach 71 98 Grimaldi 125 74 Regiomontanus ... 70 102 Gruemberger 70 127 Rutherford 72 125 "Heir Plain 74 106 Scheiner 80 124 Hipparchus 65 78 Schickard 104 113 Janssen 38 114 Schiller 93 119 Longomontanus .. 83 118 Walter 68 106 Maginus 72 119 Wilhelm I 84 114 Mare Crisium 15 50 Plates I, II, and III were taken by the writer with the 60-inch reflector of the Mount Wilson Observatory. -
0 Lunar and Planetary Institute Provided by the NASA Astrophysics Data System LUNAR CONCENTRIC CRATERS
LUNAR CONCENTRIC CRATERS. C. A. Wood, Dept. of Geological Sciences, Brown University, Providence, RI 029 12. It is generally accepted that most lunar craters formed by impact proc- esses; however, a relatively small number of craters with peculiar morpholo- gies and spatial distributions may have other origins. Physical character- istics of one of these anomalous crater types - concentric craters - are here documented and it is concluded that volcanism produced some of their unique features. Concentric craters are small (average diameter 'L8 km) craters con- taining an inner ring about & the diameter of the main crater. Morphologies of the inner rings vary from donut-like, rounded ridges to steep crater rims to flattened mounds. Table 1 lists the principal facts for the 51 lunar con- centric craters now known. Concentric structures in multi-ring basins1, large craters such as Vitello, Sabine and ~osidonius~'~,and subkilometer size craters4 are believed to have different origins than those in the cra- ters described here. Morphologies. The most common concentric crater morphology is exempli- fied by Hesiodus A (Fig. la), a 14.9 km wide fresh crater on the periphery of Mare Nubium. The inner slopes of the main crater are smooth and terrace-free (Fig. 2a), similar to normal impact craters of this diameter. The outer slopes of the inner ring appear to be slightly convex, whereas normal impact craters have concave outer slopes. According to shadow measurements the floor of the inner ring is $250 m deeper than the lowest point of the moat between the rim and ring. Hesiodus A is Q1.7 km deep, only 55% as deep as a typical fresh impact crater of the same diameter. -
And X-Band Bistatic Observations of South Polar Craters on the Moon
EPSC Abstracts Vol. 12, EPSC2018-729, 2018 European Planetary Science Congress 2018 EEuropeaPn PlanetarSy Science CCongress c Author(s) 2018 Mini-RF S- and X-band Bistatic Observations of South Polar Craters on the Moon G. W. Patterson (1), P. Prem (1), A. M. Stickle (1), J. T. S. Cahill (1), Land the Mini-RF Team (1) Johns Hopkins University Applied Physics Laboratory, Laurel, MD ([email protected]). Abstract Laboratory data and analog experiments at optical wavelengths have shown that the scattering Mini-RF S-band bistatic observations of Cabeus properties of lunar materials (e.g., CPR) can be crater floor materials display a clear opposition sensitive to variations in phase angle [6-8]. This response consistent with the presence of water ice. sensitivity manifests as an opposition effect and Initial X-band bistatic observations of Cabeus and likely involves contributions from shadow hiding at Amundsen crater floor materials do not show a low angles and coherent backscatter near 0°. Analog similar response. This could indicate that, if water ice experiments and theoretical work have shown that is present in Cabeus crater floor materials, it is buried the scattering properties of water ice are also beneath ~0.5 m of regolith that does not include sensitive to variations in phase angle, with an radar-detectible deposits of water ice. opposition effect that it is tied primarily to coherent backscatter [9-11]. Differences in the character of the opposition response of these materials offer an 1. Introduction opportunity to differentiate between them, an issue Mini-RF aboard NASA’s Lunar Reconnaissance that has been problematic for radar studies of the Orbiter (LRO) is a hybrid dual-polarized synthetic Moon that use a monostatic architecture [12,13]. -
Mini-Rf S- and X-Band Bistatic Observations of South Polar Craters on the Moon
49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083) 2007.pdf MINI-RF S- AND X-BAND BISTATIC OBSERVATIONS OF SOUTH POLAR CRATERS ON THE MOON. G.W. Patterson1, P. Prem1, A.M. Stickle1, J.T.S. Cahill1 and the Mini-RF team, 1Johns Hopkins University Applied Physics Laboratory, Laurel, MD ([email protected]). Introduction: Mini-RF aboard NASA’s Lunar on the surface of the Moon. The transmitted pulses are Reconnaissance Orbiter (LRO) is a hybrid dual- 100 to 400 µs in length. The Mini-RF receiver operates polarized synthetic aperture radar (SAR). Its receiver continuously and separately receives the horizontal and operates in concert with transmitters at either the vertical polarization components of the signal Arecibo Observatory (AO) or the Goldstone deep backscattered from the lunar surface. The resolution of space communications complex 34 meter antenna the data is ~100 m in range and ~2.5 m in azimuth but DSS-13 to collect S- and X-band bistatic radar data of can vary from observation to observation, as a function the Moon, respectively [1]. Bistatic radar data provide of the viewing geometry. For analysis, the data are a means to probe the near subsurface for the presence averaged in azimuth to provide a spatial resolution of of water ice, which exhibits a strong response in the 100 m. This yields an ~40-look average for each sam- form of a Coherent Backscatter Opposition Effect pled location in an observation and an average 1/N1/2 (CBOE). This effect has been observed in radar data uncertainty in Circular Polarization Ratio (CPR) meas- for the icy surfaces of the Galilean satellites, the polar urements of ±16%.