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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. -
Planning a Mission to the Lunar South Pole
Lunar Reconnaissance Orbiter: (Diviner) Audience Planning a Mission to Grades 9-10 the Lunar South Pole Time Recommended 1-2 hours AAAS STANDARDS Learning Objectives: • 12A/H1: Exhibit traits such as curiosity, honesty, open- • Learn about recent discoveries in lunar science. ness, and skepticism when making investigations, and value those traits in others. • Deduce information from various sources of scientific data. • 12E/H4: Insist that the key assumptions and reasoning in • Use critical thinking to compare and evaluate different datasets. any argument—whether one’s own or that of others—be • Participate in team-based decision-making. made explicit; analyze the arguments for flawed assump- • Use logical arguments and supporting information to justify decisions. tions, flawed reasoning, or both; and be critical of the claims if any flaws in the argument are found. • 4A/H3: Increasingly sophisticated technology is used Preparation: to learn about the universe. Visual, radio, and X-ray See teacher procedure for any details. telescopes collect information from across the entire spectrum of electromagnetic waves; computers handle Background Information: data and complicated computations to interpret them; space probes send back data and materials from The Moon’s surface thermal environment is among the most extreme of any remote parts of the solar system; and accelerators give planetary body in the solar system. With no atmosphere to store heat or filter subatomic particles energies that simulate conditions in the Sun’s radiation, midday temperatures on the Moon’s surface can reach the stars and in the early history of the universe before 127°C (hotter than boiling water) whereas at night they can fall as low as stars formed. -
Rare Astronomical Sights and Sounds
Jonathan Powell Rare Astronomical Sights and Sounds The Patrick Moore The Patrick Moore Practical Astronomy Series More information about this series at http://www.springer.com/series/3192 Rare Astronomical Sights and Sounds Jonathan Powell Jonathan Powell Ebbw Vale, United Kingdom ISSN 1431-9756 ISSN 2197-6562 (electronic) The Patrick Moore Practical Astronomy Series ISBN 978-3-319-97700-3 ISBN 978-3-319-97701-0 (eBook) https://doi.org/10.1007/978-3-319-97701-0 Library of Congress Control Number: 2018953700 © Springer Nature Switzerland AG 2018 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. -
Impact Cratering in the Solar System
Impact Cratering in the Solar System Michelle Kirchoff Lunar and Planetary Institute University of Houston - Clear Lake Physics Seminar March 24, 2008 Outline What is an impact crater? Why should we care about impact craters? Inner Solar System Outer Solar System Conclusions Open Questions What is an impact crater? Basically a hole in the ground… Barringer Meteor Crater (Earth) Bessel Crater (Moon) Diameter = 1.2 km Diameter = 16 km Depth = 200 m Depth = 2 km www.lpi.usra.edu What creates an “impact” crater? •Galileo sees circular features on Moon & realizes they are depressions (1610) •In 1600-1800’s many think they are volcanic features: look similar to extinct volcanoes on Earth; some even claim to see volcanic eruptions; space is empty (meteorites not verified until 1819 by Chladni) •G.K. Gilbert (1893) first serious support for lunar craters from impacts (geology and experiments) •On Earth Barringer (Meteor) crater recognized as created by impact by Barringer (1906) •Opik (1916) - impacts are high velocity, thus create circular craters at most impact angles Melosh, 1989 …High-Velocity Impacts! www.lpl.arizona.edu/SIC/impact_cratering/Chicxulub/Animation.gif Physics of Impact Cratering Understand how stress (or shock) waves propagate through material in 3 stages: 1. Contact and Compression 2. Excavation 3. Modification www.psi.edu/explorecraters/background.htm Hugoniot Equations Derived by P.H. Hugoniot (1887) to describe shock fronts using conservation of mass, momentum and energy across the discontinuity. equation (U-up) = oU of state P-Po = oupU E-Eo = (P+Po)(Vo-V)/2 P - pressure U - shock velocity up - particle velocity E - specific internal energy V = 1/specific volume) Understanding Crater Formation laboratory large simulations explosives (1950’s) (1940’s) www.nasa.gov/centers/ames/ numerical simulations (1960’s) www.lanl.gov/ Crater Morphology • Simple • Complex • Central peak/pit • Peak ring www3.imperial.ac. -
March 21–25, 2016
FORTY-SEVENTH LUNAR AND PLANETARY SCIENCE CONFERENCE PROGRAM OF TECHNICAL SESSIONS MARCH 21–25, 2016 The Woodlands Waterway Marriott Hotel and Convention Center The Woodlands, Texas INSTITUTIONAL SUPPORT Universities Space Research Association Lunar and Planetary Institute National Aeronautics and Space Administration CONFERENCE CO-CHAIRS Stephen Mackwell, Lunar and Planetary Institute Eileen Stansbery, NASA Johnson Space Center PROGRAM COMMITTEE CHAIRS David Draper, NASA Johnson Space Center Walter Kiefer, Lunar and Planetary Institute PROGRAM COMMITTEE P. Doug Archer, NASA Johnson Space Center Nicolas LeCorvec, Lunar and Planetary Institute Katherine Bermingham, University of Maryland Yo Matsubara, Smithsonian Institute Janice Bishop, SETI and NASA Ames Research Center Francis McCubbin, NASA Johnson Space Center Jeremy Boyce, University of California, Los Angeles Andrew Needham, Carnegie Institution of Washington Lisa Danielson, NASA Johnson Space Center Lan-Anh Nguyen, NASA Johnson Space Center Deepak Dhingra, University of Idaho Paul Niles, NASA Johnson Space Center Stephen Elardo, Carnegie Institution of Washington Dorothy Oehler, NASA Johnson Space Center Marc Fries, NASA Johnson Space Center D. Alex Patthoff, Jet Propulsion Laboratory Cyrena Goodrich, Lunar and Planetary Institute Elizabeth Rampe, Aerodyne Industries, Jacobs JETS at John Gruener, NASA Johnson Space Center NASA Johnson Space Center Justin Hagerty, U.S. Geological Survey Carol Raymond, Jet Propulsion Laboratory Lindsay Hays, Jet Propulsion Laboratory Paul Schenk, -
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. -
Mercury Friday, February 23
ASTRONOMY 161 Introduction to Solar System Astronomy Class 18 Mercury Friday, February 23 Mercury: Basic characteristics Mass = 3.302×1023 kg (0.055 Earth) Radius = 2,440 km (0.383 Earth) Density = 5,427 kg/m³ Sidereal rotation period = 58.6462 d Albedo = 0.11 (Earth = 0.39) Average distance from Sun = 0.387 A.U. Mercury: Key Concepts (1) Mercury has a 3-to-2 spin-orbit coupling (not synchronous rotation). (2) Mercury has no permanent atmosphere because it is too hot. (3) Like the Moon, Mercury has cratered highlands and smooth plains. (4) Mercury has an extremely large iron-rich core. (1) Mercury has a 3-to-2 spin-orbit coupling (not synchronous rotation). Mercury is hard to observe from the Earth (because it is so close to the Sun). Its rotation speed can be found from Doppler shift of radar signals. Mercury’s unusual orbit Orbital period = 87.969 days Rotation period = 58.646 days = (2/3) x 87.969 days Mercury is NOT in synchronous rotation (1 rotation per orbit). Instead, it has 3-to-2 spin-orbit coupling (3 rotations for 2 orbits). Synchronous rotation (WRONG!) 3-to-2 spin-orbit coupling (RIGHT!) Time between one noon and the next is 176 days. Sun is above the horizon for 88 days at the time. Daytime temperatures reach as high as: 700 Kelvin (800 degrees F). Nighttime temperatures drops as low as: 100 Kelvin (-270 degrees F). (2) Mercury has no permanent atmosphere because it is too hot (and has low escape speed). Temperature is a measure of the 3kT v = random speed of m atoms (or v typical speed of atom molecules). -
South Pole-Aitken Basin
Feasibility Assessment of All Science Concepts within South Pole-Aitken Basin INTRODUCTION While most of the NRC 2007 Science Concepts can be investigated across the Moon, this chapter will focus on specifically how they can be addressed in the South Pole-Aitken Basin (SPA). SPA is potentially the largest impact crater in the Solar System (Stuart-Alexander, 1978), and covers most of the central southern farside (see Fig. 8.1). SPA is both topographically and compositionally distinct from the rest of the Moon, as well as potentially being the oldest identifiable structure on the surface (e.g., Jolliff et al., 2003). Determining the age of SPA was explicitly cited by the National Research Council (2007) as their second priority out of 35 goals. A major finding of our study is that nearly all science goals can be addressed within SPA. As the lunar south pole has many engineering advantages over other locations (e.g., areas with enhanced illumination and little temperature variation, hydrogen deposits), it has been proposed as a site for a future human lunar outpost. If this were to be the case, SPA would be the closest major geologic feature, and thus the primary target for long-distance traverses from the outpost. Clark et al. (2008) described four long traverses from the center of SPA going to Olivine Hill (Pieters et al., 2001), Oppenheimer Basin, Mare Ingenii, and Schrödinger Basin, with a stop at the South Pole. This chapter will identify other potential sites for future exploration across SPA, highlighting sites with both great scientific potential and proximity to the lunar South Pole. -
Mariner 10 Observations of Field-Aligned Currents at Mercury
Planet. Space Sci., Vol. 45, No. 1, pp. 133-141, 1997 Pergamon #I? 1997 Published bv Elsevier Science Ltd P&ted in Great Brit& All rights reserved 0032-0633/97 $17.00+0.00 PII: S0032-0633(96)00104-3 Mariner 10 observations of field-aligned currents at Mercury J. A. Slavin,’ J. C. J. Owen,’ J. E. P. Connerney’ and S. P. Christon ‘Laboratory for Extraterrestrial Physics, NASA/GSFC, Greenbelt, MD 20771, U.S.A. ‘Astronomy Unit, Queen Mary and Westfield College, London, U.K. 3Department of Physics, University of Maryland, College Park, MD 20742, U.S.A. Received 5 October 1995; revised 11 April 1996; accepted 13 April 1996 magnetic field at Mercury with a dipole moment of about 300nT R& (see review by Connerney and Ness (1988)). This magnetic field is sufficient to stand-off the average solar wind at an altitude of about 1 RM as depicted in Fig. 1 (see review by Russell et al. (1988)). For the purposes of comparison the diameter of the Earth is indicated at the bottom of the figure (i.e. 1 RE = 6380 km ; 1 RM = 2439 km). Whether or not the solar wind is ever able to compress and/or erode the dayside magnetosphere to the point where solar wind ions could directly impact the surface remains a topic of considerable controversy (Siscoe and Christopher, 1975 ; Slavin and Holzer, 1979 ; Hood and Schubert, 1979; Suess and Goldstein, 1979; Goldstein et al., 1981). Overall, the basic morphology of this small mag- netosphere appears quite similar to that of the Earth. -
Origin and Evolution of the Moon's Procellarum KREEP
Decadal Survey 2023 White Paper: Origin and Evolution of the Procellarum KREEP Terrane Origin and Evolution of the Moon’s Procellarum KREEP Terrane A White Paper submitted to the 2023 Planetary Science Decadal Survey, July 15, 2020 Authorship Brad Jolliff, Washington University in St. Louis, [email protected] Mark Robinson, Arizona State University, [email protected] Srinidhi Ravi, Arizona State University, [email protected] Co-signatories on the last page The Procellarum KREEP Terrane on the Moon’s nearside is a unique province that produced volcanism over an extended period of the Moon’s history. Thermal evolution of the lunar mantle in this region may have been driven by a high concentration of radiogenic heat-producing elements. This region is key to unlocking the thermal evolution of the Moon and may have implications for our understanding of extensive volcanism on other inner Solar System bodies such as Mercury and Mars. Major volcanic features of this terrane could be explored by a long-distance rover in a New Frontiers class mission to answer questions about how this planetary asymmetry formed, why volcanism was so voluminous in this region, and how it persisted for nearly 4 billion years. Introduction. The Moon displays a fundamental asymmetry that has been evident since the first images of the farside revealed an ancient, mountainous, heavily cratered feldspathic highlands but very little of the low-lying, dark basaltic plains that are prominent on the nearside, especially the western regions that incorporate Oceanus Procellarum, Imbrium, and several other nearside impact basins. Apollo orbital remote sensing revealed the first glimpses of compositional variations that corresponded to the hemispheric asymmetry, but only in narrow, near-equatorial orbital swaths. -
1 the Lifecycle of Hollows on Mercury
The Lifecycle of Hollows on Mercury: An Evaluation of Candidate Volatile Phases and a Novel Model of Formation. 1 1 2 3 M. S. Phillips , J. E. Moersch , C. E. Viviano , J. P. Emery 1Department of Earth and Planetary Sciences, University of Tennessee, Knoxville 2Planetary Exploration Group, Johns Hopkins University Applied Physics Laboratory 3Department of Astronomy and Planetary Sciences, Northern Arizona University Corresponding author: Michael Phillips ([email protected]) Keywords: Mercury, hollows, thermal model, fumarole. Abstract On Mercury, high-reflectance, flat-floored depressions called hollows are observed nearly globally within low-reflectance material, one of Mercury’s major color units. Hollows are thought to be young, or even currently active, features that form via sublimation, or a “sublimation-like” process. The apparent abundance of sulfides within LRM combined with spectral detections of sulfides associated with hollows suggests that sulfides may be the phase responsible for hollow formation. Despite the association of sulfides with hollows, it is still not clear whether sulfides are the hollow-forming phase. To better understand which phase(s) might be responsible for hollow formation, we calculated sublimation rates for 57 candidate hollow-forming volatile phases from the surface of Mercury and as a function of depth beneath regolith lag deposits of various thicknesses. We found that stearic acid (C18H36O2), fullerenes (C60, C70), and elemental sulfur (S) have the appropriate thermophysical properties to explain hollow formation. Stearic acid and fullerenes are implausible hollow-forming phases because they are unlikely to have been delivered to or generated on Mercury in high enough volume to account for hollows. -
Late Heavy Bombardment
Late Heavy Bombardment The Late Heavy Bombardment (abbreviated LHB and also known as the lunar cataclysm) is an event thought to have occurred approximately 4.1 to 3.8 billion years (Ga) ago,[1] at a time corresponding to the Neohadean and Eoarchean eras on Earth. During this interval, a disproportionately large number of asteroids are theorized to have collided with the early terrestrial planets in the inner Solar System, including Mercury, Venus, Earth, and Mars.[2] The Late Heavy Bombardment happened after the Earth and other rocky planets had formed and accreted most of their mass, but still quite early in Earth's history. Evidence for the LHB derives from lunar samples brought back by the Apollo astronauts. Isotopic dating of Moon rocks implies that most impact melts occurred in a rather narrow interval of time. Several hypotheses attempt to explain the apparent spike in the flux of impactors (i.e. asteroids and comets) in the inner Solar System, but no consensus yet exists. The Nice model, popular among planetary scientists, postulates that the giant planets underwent orbital Artist's impression of the Moon during the Late Heavy Bombardment (above) migration and in doing so, scattered objects in the asteroid and/or Kuiper belts and today (below). into eccentric orbits, and into the path of the terrestrial planets. Other researchers argue that the lunar sample data do not require a ataclysmicc cratering event near 3.9 Ga, and that the apparent clustering of impact-melt ages near this time is an artifact of sampling materials retrieved