DOCSLIB.ORG

Investigating Mineral Stability Under Venus Conditions: a Focus on the Venus Radar Anomalies Erika Kohler University of Arkansas, Fayetteville

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Investigating Mineral Stability Under Venus Conditions: a Focus on the Venus Radar Anomalies Erika Kohler University of Arkansas, Fayetteville University of Arkansas, Fayetteville ScholarWorks@UARK Theses and Dissertations 5-2016 Investigating Mineral Stability under Venus Conditions: A Focus on the Venus Radar Anomalies Erika Kohler University of Arkansas, Fayetteville Follow this and additional works at: http://scholarworks.uark.edu/etd Part of the Geochemistry Commons, Mineral Physics Commons, and the The unS and the Solar System Commons Recommended Citation Kohler, Erika, "Investigating Mineral Stability under Venus Conditions: A Focus on the Venus Radar Anomalies" (2016). Theses and Dissertations. 1473. http://scholarworks.uark.edu/etd/1473 This Dissertation is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of ScholarWorks@UARK. For more information, please contact [email protected], [email protected]. Investigating Mineral Stability under Venus Conditions: A Focus on the Venus Radar Anomalies A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Space and Planetary Sciences by Erika Kohler University of Oklahoma Bachelors of Science in Meteorology, 2010 May 2016 University of Arkansas This dissertation is approved for recommendation to the Graduate Council. ____________________________ Dr. Claud H. Sandberg Lacy Dissertation Director Committee Co-Chair ____________________________ ___________________________ Dr. Vincent Chevrier Dr. Larry Roe Committee Co-chair Committee Member ____________________________ ___________________________ Dr. John Dixon Dr. Richard Ulrich Committee Member Committee Member Abstract Radar studies of the surface of Venus have identified regions with high radar reflectivity concentrated in the Venusian highlands: between 2.5 and 4.75 km above a planetary radius of 6051 km, though it varies with latitude. Previous research has proposed several theories on the source of these anomalies, including increased surface roughness, metallic materials with higher dielectric constants, or ferroelectric materials. Prior work suggests several processes that could be the origin of these anomalies, such as surface-atmospheric interactions or low lying clouds or fog. Alternatively, these anomalies could result from a semi-metallic compound trapped at the cooler conditions in the highlands, likely forming as a snow or frost. If this were the case, the compound would be expected to precipitate out of a low cloud layer. While theoretical studies have been beneficial towards determining the source of these anomalies, few experimental investigations have been done to validate these theories. In this dissertation, several minerals, chosen by their likely presence on Venus, were investigated to determine their stability under Venusian conditions, including temperature, pressure and atmospheric composition. Analysis of the empirical data enabled the identification of potential mineral source(s) of the radar-bright anomalies. Acknowledgements A special thanks goes to my adviser Dr. Claud Sandberg Lacy who supported me and encouraged me from day one. To Dr. Vincent Chevrier, I would not be half the scientist or the professional today if it were not for you. Through your mentoring and advisement, the both of you have had a profound effect on my knowledge, and my personal growth. Thank you. I also gratefully acknowledge the members of my committee: Dr. John Dixon, Dr. Larry Roe, and Dr. Richard Ulrich for their support, advice, and helpful conversations. This work was funded in part by the NASA Harriett G. Jenkins Pre-doctoral Research Fellowship, and the Arkansas Space Grant Fellowship. The availability of the chamber would not be possible without the support of NASA and Goddard Space Flight Center. A special thanks to the people at NASA who helped and supported me: Elizabeth Cartier, Dr. Joseph Nuth, Dr. Frank Ferguson, Norm Dobson, and especially Dr. Natasha Johnson. Special recognition is given to Dr. Patricia Craig, for all of the support, mentorship, and friendship she has given me. I also thank Dr. Sanjay Limaye for providing me with many opportunities for professional development, and Sara Port and Jonathan Guandique for project support. I would like to express my deepest appreciation for my family who has provided me with unceasing encouragement. Your faith in me gave me strength. Finally, though there are too many to name, I would like to thank my friends, especially Dr. Seth Jonas, Hannah Bellah, Dr. Fares Beainy, Dr. Cassie Marnocha, and Rebecca Mickol, for their vital support and encouragement. I would not have made it here without you. Dedication To my siblings: Corey Mumma, Andrew Kohler, and William Kohler, I hope you accomplish every goal you set out for. To my grandparents: Donald and Sheryl Dale, who are always there for me when I need them. To my father: Steven Kohler, who encouraged me and helped me overcome all of the obstacles I faced when no one else could. And to my mother: Carolyn Dale, whose support meant, and still means, everything to me. You inspire me and I would not be here without you. My accomplishment is yours as it would not have been possible without you. Table of Contents 1 Introduction ........................................................................................................................... 1 1.1 Planetary Radar Astronomy Applied to Venus ................................................................ 1 1.1.1 Observations .......................................................................................................... 2 1.1.2 General Concepts .................................................................................................. 5 1.1.3 Surface Properties – Dielectric Constant ............................................................... 7 1.2 Previous Work .................................................................................................................. 7 1.2.1 Mechanisms ........................................................................................................... 8 1.2.2 Compositional Sources ........................................................................................ 10 1.3 Dissertation Goals and Significance .............................................................................. 13 1.4 Dissertation Outline........................................................................................................ 15 1.5 References ...................................................................................................................... 15 2 Radar Anomaly (Venus) ..................................................................................................... 19 2.1 Definition ....................................................................................................................... 19 2.2 Category ......................................................................................................................... 19 2.3 Description ..................................................................................................................... 19 2.4 Subtypes ......................................................................................................................... 19 2.5 Interpretation (Inferred Composition) ............................................................................ 19 2.6 Formation ....................................................................................................................... 20 2.7 Age ................................................................................................................................. 21 2.8 Prominent Examples ...................................................................................................... 21 2.9 Distribution..................................................................................................................... 21 2.10 Significance .................................................................................................................... 21 2.11 Terrestrial Analog .......................................................................................................... 22 2.12 History of Investigation .................................................................................................. 22 2.12 See Also.......................................................................................................................... 22 2.13 References ...................................................................................................................... 22 3 Experimental Investigation of Tellurium Compounds as Sources for the Venusian Radar Anomalies ......................................................................................................................... 25 3.1 Abstract: ......................................................................................................................... 25 3.2 Introduction .................................................................................................................... 25 3.2.1 Radar Anomalies on the Venusian Highlands ..................................................... 25 3.2.2 Previous Works ................................................................................................... 26 3.2.3 Surface Properties – Dielectric Constant ............................................................. 27 3.3 Methods .........................................................................................................................
Load more

Recommended publications
  • Planetary Geologic Mappers Annual Meeting
    Program Lunar and Planetary Institute 3600 Bay Area Boulevard Houston TX 77058-1113 Planetary Geologic Mappers Annual Meeting June 12–14, 2018 • Knoxville, Tennessee Institutional Support Lunar and Planetary Institute Universities Space Research Association Convener Devon Burr Earth and Planetary Sciences Department, University of Tennessee Knoxville Science Organizing Committee David Williams, Chair Arizona State University Devon Burr Earth and Planetary Sciences Department, University of Tennessee Knoxville Robert Jacobsen Earth and Planetary Sciences Department, University of Tennessee Knoxville Bradley Thomson Earth and Planetary Sciences Department, University of Tennessee Knoxville Abstracts for this meeting are available via the meeting website at https://www.hou.usra.edu/meetings/pgm2018/ Abstracts can be cited as Author A. B. and Author C. D. (2018) Title of abstract. In Planetary Geologic Mappers Annual Meeting, Abstract #XXXX. LPI Contribution No. 2066, Lunar and Planetary Institute, Houston. Guide to Sessions Tuesday, June 12, 2018 9:00 a.m. Strong Hall Meeting Room Introduction and Mercury and Venus Maps 1:00 p.m. Strong Hall Meeting Room Mars Maps 5:30 p.m. Strong Hall Poster Area Poster Session: 2018 Planetary Geologic Mappers Meeting Wednesday, June 13, 2018 8:30 a.m. Strong Hall Meeting Room GIS and Planetary Mapping Techniques and Lunar Maps 1:15 p.m. Strong Hall Meeting Room Asteroid, Dwarf Planet, and Outer Planet Satellite Maps Thursday, June 14, 2018 8:30 a.m. Strong Hall Optional Field Trip to Appalachian Mountains Program Tuesday, June 12, 2018 INTRODUCTION AND MERCURY AND VENUS MAPS 9:00 a.m. Strong Hall Meeting Room Chairs: David Williams Devon Burr 9:00 a.m.
    [Show full text]
  • Copyrighted Material
    Index Abulfeda crater chain (Moon), 97 Aphrodite Terra (Venus), 142, 143, 144, 145, 146 Acheron Fossae (Mars), 165 Apohele asteroids, 353–354 Achilles asteroids, 351 Apollinaris Patera (Mars), 168 achondrite meteorites, 360 Apollo asteroids, 346, 353, 354, 361, 371 Acidalia Planitia (Mars), 164 Apollo program, 86, 96, 97, 101, 102, 108–109, 110, 361 Adams, John Couch, 298 Apollo 8, 96 Adonis, 371 Apollo 11, 94, 110 Adrastea, 238, 241 Apollo 12, 96, 110 Aegaeon, 263 Apollo 14, 93, 110 Africa, 63, 73, 143 Apollo 15, 100, 103, 104, 110 Akatsuki spacecraft (see Venus Climate Orbiter) Apollo 16, 59, 96, 102, 103, 110 Akna Montes (Venus), 142 Apollo 17, 95, 99, 100, 102, 103, 110 Alabama, 62 Apollodorus crater (Mercury), 127 Alba Patera (Mars), 167 Apollo Lunar Surface Experiments Package (ALSEP), 110 Aldrin, Edwin (Buzz), 94 Apophis, 354, 355 Alexandria, 69 Appalachian mountains (Earth), 74, 270 Alfvén, Hannes, 35 Aqua, 56 Alfvén waves, 35–36, 43, 49 Arabia Terra (Mars), 177, 191, 200 Algeria, 358 arachnoids (see Venus) ALH 84001, 201, 204–205 Archimedes crater (Moon), 93, 106 Allan Hills, 109, 201 Arctic, 62, 67, 84, 186, 229 Allende meteorite, 359, 360 Arden Corona (Miranda), 291 Allen Telescope Array, 409 Arecibo Observatory, 114, 144, 341, 379, 380, 408, 409 Alpha Regio (Venus), 144, 148, 149 Ares Vallis (Mars), 179, 180, 199 Alphonsus crater (Moon), 99, 102 Argentina, 408 Alps (Moon), 93 Argyre Basin (Mars), 161, 162, 163, 166, 186 Amalthea, 236–237, 238, 239, 241 Ariadaeus Rille (Moon), 100, 102 Amazonis Planitia (Mars), 161 COPYRIGHTED
    [Show full text]
  • IAC-04-Q.2.A.07 VENUS EXPRESS on the RIGHT TRACK
    IAC-04-Q.2.a.07 VENUS EXPRESS ON THE RIGHT TRACK J. Fabrega & T. Schirmann (1); R. Schmidt & D. McCoy (2) (1) EADS Astrium, 31 Avenue des Cosmonautes, 31042 Toulouse Cedex 4, France (2) ESA/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, Netherlands E-mail : [email protected] ASTRACT will allow meeting the challenge. Venus Express is on the right track!. On October 26th of next year, Venus Express spacecraft will depart from Baikonur on-board the Soyuz/Fregat Launch Vehicle. It will be the very first 1 INTRODUCTION European mission to the “morning star”, two years after the first European trip to Mars. Venus Express In the wee small hours of Christmas 2003, Mars will carry 7 science payloads dedicated to global Express was successfully inserted into Mars orbit. investigation of Venus atmosphere. Three Very first European spacecraft to ever orbit a planet, spectrometers covering wavelength range from UV it has been producing outstanding science results to IR, one plasma analyzer, one magnetometer, one since its arrival. imager and one radio-science experience, most of More than two years before Mars Express launch, them derived from similar instruments of Rosetta ESA asked for suggestions on how to reuse the and Mars Express, will map the whole atmosphere same platform. Guidelines were to use the same below 200 km, trying to solve some of Venus units and the same industrial teams, in order to be mysteries. After a 5 months journey, they will ready to fly in 2005. Out of 9 promising proposals, operate during at least 500 days, the nominal ESA selected Venus Express.
    [Show full text]
  • Art Gallery of New South Wales Annual Report 2012 – 13
    ART GALLERY OF NEW SOUTH WALES ANNUAL REPORT 2012 – 13 1 CONTENTS 4 Vision and strategic direction 2010 – 15 5 President’s foreword 9 Director’s statement 13 At a glance 15 Access 15 Exhibitions and audience programs 19 Future exhibitions 21 Publishing 23 Engaging 23 Digital engagement 23 Community 30 Education 35 Outreach Regional NSW 40 Stewarding 40 Building and environmental management 42 Corporate Governance 58 Collecting 58 Major collection acquisitions 67 Other collection activity 70 Appendices 123 General Access Information 131 Financial statements 2 ART GALLERY OF NSW ANNUAL REPORT 12-13 The Hon George Souris MP Minister for Tourism, Major Events, Hospitality and Racing, and Minister for the Arts Parliament House Macquarie Street SYDNEY NSW 2000 Dear Minister It is our pleasure to forward to you for presentation to the NSW Parliament the annual report for the Art Gallery of NSW for the year ended 30 June 2013. This report has been prepared in accordance with the provisions of the Annual Report (Statutory Bodies) Act 1984 and the Annual Reports (Statutory Bodies) Regulations 2010. Yours sincerely Steven Lowy Michael Brand President Director Art Gallery of NSW Trust 21 October 2013 3 VISION AND STRATEGIC DIRECTION 2010 – 2015 Vision The Gallery is dedicated to serving the widest possible audience, both nationally and internationally, as a centre of excellence for the collection, preservation, documentation, . interpretation and display of Australian and international art. The Gallery is also dedicated to providing a forum for scholarship, art education and the exchange of ideas. Strategic Directions Access To continue to improve access to our collection, resources and expertise through exhibitions, publishing, programs, new technologies and partnerships.
    [Show full text]
  • CRATER MORPHOMETRY on VENUS. C. G. Cochrane, Imperial College, London ([email protected])
    Lunar and Planetary Science XXXIV (2003) 1173.pdf CRATER MORPHOMETRY ON VENUS. C. G. Cochrane, Imperial College, London ([email protected]). Introduction: Most impact craters on Venus are propagating east and north/south. Can be minimised if pristine, and provide probably the best available ana- framelets have good texture on the left-hand side. logs for craters on Earth soon after impact; hence the Prominence extension – features extend down value of measuring their 3-D shape to known accuracy. range into a ridge, eg central peak linked to the rim. The USGS list 967 craters: from the largest, Mead at Probably due to radar shadowing differences, these are 270 km diameter, to the smallest, unnamed at 1.3 km. easily recognised and avoided during analysis. Initially, research focussed on the larger craters. Araration (from Latin: Arare to plough) consists of Schaber et al [1] (11 craters >50 km) and Ivanov et al parallel furrows some 50 pixels apart, oriented north- [2] (31 craters >70 km) took crater depth from Magel- south, and at least tens of metres deep. Fig 2, a lan altimetry. Sharpton [3] (94 craters >18 km) used floor-offsets in Synthetic Aperture Radar (SAR) F- MIDR pairs, as did Herrick & Phillips [4]. They list many parameters but not depth for 891 craters. The LPI database1 now numbers 941. Herrick & Sharpton [5] made Digital Elevation Models (DEMs) of all cra- ters at least partially imaged twice down to 12 km, and 20 smaller craters down to 3.6 km. Using FMAP im- ages and the Magellan Stereo Toolkit (MST) v.1, they automated matches every 900m but then manually ed- ited the resultant data.
    [Show full text]
  • Winds in the Lower Cloud Level on the Nightside of Venus from VIRTIS-M (Venus Express) 1.74 Μm Images
    atmosphere Article Winds in the Lower Cloud Level on the Nightside of Venus from VIRTIS-M (Venus Express) 1.74 µm Images Dmitry A. Gorinov * , Ludmila V. Zasova, Igor V. Khatuntsev, Marina V. Patsaeva and Alexander V. Turin Space Research Institute, Russian Academy of Sciences, 117997 Moscow, Russia; [email protected] (L.V.Z.); [email protected] (I.V.K.); [email protected] (M.V.P.); [email protected] (A.V.T.) * Correspondence: [email protected] Abstract: The horizontal wind velocity vectors at the lower cloud layer were retrieved by tracking the displacement of cloud features using the 1.74 µm images of the full Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS-M) dataset. This layer was found to be in a superrotation mode with a westward mean speed of 60–63 m s−1 in the latitude range of 0–60◦ S, with a 1–5 m s−1 westward deceleration across the nightside. Meridional motion is significantly weaker, at 0–2 m s−1; it is equatorward at latitudes higher than 20◦ S, and changes its direction to poleward in the equatorial region with a simultaneous increase of wind speed. It was assumed that higher levels of the atmosphere are traced in the equatorial region and a fragment of the poleward branch of the direct lower cloud Hadley cell is observed. The fragment of the equatorward branch reveals itself in the middle latitudes. A diurnal variation of the meridional wind speed was found, as east of 21 h local time, the direction changes from equatorward to poleward in latitudes lower than 20◦ S.
    [Show full text]
  • SFSC Search Down to 4
    C M Y K www.newssun.com EWS UN NHighlands County’s Hometown-S Newspaper Since 1927 Rivalry rout Deadly wreck in Polk Harris leads Lake 20-year-old woman from Lake Placid to shutout of AP Placid killed in Polk crash SPORTS, B1 PAGE A2 PAGE B14 Friday-Saturday, March 22-23, 2013 www.newssun.com Volume 94/Number 35 | 50 cents Forecast Fire destroys Partly sunny and portable at Fred pleasant High Low Wild Elementary Fire alarms “Myself, Mr. (Wally) 81 62 Cox and other administra- Complete Forecast went off at 2:40 tors were all called about PAGE A14 a.m. Wednesday 3 a.m.,” Waldron said Wednesday morning. Online By SAMANTHA GHOLAR Upon Waldron’s arrival, [email protected] the Sebring Fire SEBRING — Department along with Investigations into a fire DeSoto City Fire early Wednesday morning Department, West Sebring on the Fred Wild Volunteer Fire Department Question: Do you Elementary School cam- and Sebring Police pus are under way. Department were all on think the U.S. govern- The school’s fire alarms the scene. ment would ever News-Sun photo by KATARA SIMMONS Rhoda Ross reads to youngsters Linda Saraniti (from left), Chyanne Carroll and Camdon began going off at approx- State Fire Marshal seize money from pri- Carroll on Wednesday afternoon at the Lake Placid Public Library. Ross was reading from imately 2:40 a.m. and con- investigator Raymond vate bank accounts a children’s book she wrote and illustrated called ‘A Wildflower for all Seasons.’ tinued until about 3 a.m., Miles Davis was on the like is being consid- according to FWE scene for a large part of ered in Cyprus? Principal Laura Waldron.
    [Show full text]
  • Cleopatra Crater on Venus: Happy Solution of the Volcanic Vs
    CLEOPATRA CRATER ON VENUS: HAPPY SOLUTION OF THE VOLCANIC VS. IMPACT CRATER CONTROVERSY; A.T. Basilevsky, A.T. Vernadsky Institute of Geochemistry and Analytical chemistry, Moscow, USSR, and G.G. Schaber, U.S. Geological Survey, Flagstaff AZ 86001 ~ntroduction. Cleopatra is a 100-km-diameter crater on the eastern slope of Maxwell Montes in western Ishtar Terra. For over 12 years, Cleopatra has been the subject of scientific controversy. Discovered during the Pioneer Venus altimetric survey, this feature was initially interpreted as a caldera near the top of a giant volcanic construct, Maxwell Montes [I]. Venera 15/16 data and recent Arecibo radar images show, however, that the Maxwell Montes appear to be more of a tectonic construct, with little or no resemblance to other giant shields known in the Solar System; thus, a nonvolcanic origin of Cleopatra was proposed [2-61. The similarity of the double-ring structure of Cleopatra to those of other multi-ring impact craters of similar size on Venus and the Moon, Mercury, and Mars was more recently given by Basilevsky and Ivanov [7] as the primarily reason to consider this feature an impact crater. At the same time, some characteristics of Cleopatra seemed to contradict an impact origin. For example, Schaber et al. [8], suggestingthat a definitive verification of a volcanic or impact origin would probably require Magellan data, proposed that the evidence from Venera 15/16 and earlier data for a probable volcanic origin for Cleopatra is substantial. They cited, among other points: (1) the absence of a raised rim and highly backscattering ejecta deposits; (2) the crater's association with plains-forming deposits immediately downslope to the east, interpreted as probable lava flows emanating from a distinct breach in the crater's rim; (3) the excessive depth (2.5 km) and depth-to-diameter ratio (0.028) of the crater, (4) the offset of the inner and outer craters; and (5) the crater's position in what was interpreted as a regional tectonic framework.
    [Show full text]
  • Styles of Deformation in Ishtar Terra and Their Implications
    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 97, NO. El0, PAGES 16,085-16,120, OCTOBER 25, 1992 Stylesof Deformationin IshtarTerra and Their Implications Wn.T.TAMM. KAU•A,• DOAN•L. BINDSCHAD•-R,l ROBERT E. GPaM•,2'3 VICKIL. HANSEN,2KARl M. ROBERTS,4AND SUZANNE E. SMREr,AR s IshtarTerra, the highest region on Venus, appears to havecharacteristics of both plume uplifts and convergent belts.Magellan imagery over longitudes 330ø-30øE indicates a great variety of tectonicand volcanic activity, with largevariations within distances of onlya few 100km. Themost prominent terrain types are the volcanic plains of Lakshmiand the mountain belts of Maxwell,Freyja, and Danu. Thebelts appear to havemarked variations in age. Thereare also extensive regions of tesserain boththe upland and outboard plateaus, some rather featureless smoothscarps, flanking basins of complexextensional tectonics, and regions of gravitationalor impactmodifica- tion.Parts of Ishtarare the locations of contemporaryvigorous tectonics and past extensive volcanism. Ishtar appearsto be the consequence of a history of several100 m.y., in whichthere have been marked changes in kinematic patternsand in whichactivity at any stage has been strongly influenced by the past. Ishtar demonstrates three general propertiesof Venus:(1) erosionaldegradation is absent,leading to preservationof patternsresulting from past activity;(2) manysurface features are the responses ofa competentlayer less than 10 km thick to flowsof 100km orbroaderscale; and (3) thesebroader scale flows are controlled mainly by heterogeneities inthe mantle. Ishtar Terra doesnot appear to bethe result of a compressionconveyed by anEarthlike lithosphere. But there is stilldoubt as to whetherIshtar is predominantlythe consequence of a mantleupflow or downflow.Upflow is favoredby the extensivevolcanic plain of Lakshmiand the high geoid: topography ratio; downflow is favoredby the intense deformationof themountain belts and the absence of majorrifts.
    [Show full text]
  • The Magellan Spacecraft at Venus by Andrew Fraknoi, Astronomical Society of the Pacific
    www.astrosociety.org/uitc No. 18 - Fall 1991 © 1991, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112. The Magellan Spacecraft at Venus by Andrew Fraknoi, Astronomical Society of the Pacific "Having finally penetrated below the clouds of Venus, we find its surface to be naked [not hidden], revealing the history of hundreds of millions of years of geological activity. Venus is a geologist's dream planet.'' —Astronomer David Morrison This fall, the brightest star-like object you can see in the eastern skies before dawn isn't a star at all — it's Venus, the second closest planet to the Sun. Because Venus is so similar in diameter and mass to our world, and also has a gaseous atmosphere, it has been called the Earth's "sister planet''. Many years ago, scientists expected its surface, which is perpetually hidden beneath a thick cloud layer, to look like Earth's as well. Earlier this century, some people even imagined that Venus was a hot, humid, swampy world populated by prehistoric creatures! But we now know Venus is very, very different. New radar images of Venus, just returned from NASA's Magellan spacecraft orbiting the planet, have provided astronomers the clearest view ever of its surface, revealing unique geological features, meteor impact craters, and evidence of volcanic eruptions different from any others found in the solar system. This issue of The Universe in the Classroom is devoted to what Magellan is teaching us today about our nearest neighbor, Venus. Where is Venus, and what is it like? Spacecraft exploration of Venus's surface Magellan — a "recycled'' spacecraft How does Magellan take pictures through the clouds? What has Magellan revealed about Venus? How does Venus' surface compare with Earth's? What is the next step in Magellan's mission? If Venus is such an uninviting place, why are we interested in it? Reading List Why is it so hot on Venus? Where is Venus, and what is it like? Venus orbits the Sun in a nearly circular path between Mercury and the Earth, about 3/4 as far from our star as the Earth is.
    [Show full text]
  • User Guide to the Magellan Synthetic Aperture Radar Images
    https://ntrs.nasa.gov/search.jsp?R=19950018567 2020-06-16T07:22:10+00:00Z User Guide to the Magellan Synthetic Aperture Radar Images Stephen D. Wall Shannon L. McConnell Craig E. Left Richard S. Austin Kathi K. Beratan Mark J. Rokey National Aeronautics and Jet Propulsion Laboratory Space Administration California Institute of Technology Scientific and Technical Pasadena, California Information Branch NASA Reference Publication 1356 March 1995 This publication was prepared at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Contents Iri Introduction .................................................................................................................................................................... 1 I_1 The Spacecraft ................................................................................................................................................................ 2 IB Mission Design ................................................................................................................................................................ 4 D Experiment Description ................................................................................................................................................ 15 B Mission Operations ....................................................................................................................................................... 17 [] Notable Events and Problems .....................................................................................................................................
    [Show full text]
  • New Arecibo High-Resolution Radar Images of Venus: Preliminary Interpretation D
    142 LPSC XX New Arecibo High-Resolution Radar Images of Venus: Preliminary Interpretation D. B. carnpbelll, A. A. I4ine2, J. K. IXarmon2, D. A. senske3, R. W. Vorder ~rue~~e~,P. C. ish her^, S. rank^, and J. W. ~ead~1) National Astronomy and Ionosphere Center, Cornell University, Ithaca NY 14853. 2) National Astronomy and Ionosphere Center, Arecibo Observatory, Arecibo, Puerto Rico 00612. 3) Department of Geological Sciences, Brown University, Providence, RI 02912. btroduction: New observations of Venus with the Arecibo radar (wavelength 12.6 cm) in the summer of 1988 will provide images at 1.5-2.5 km resolution over the longitude range 260' to 20" in the latitude bands 12' N to 70' N and 12' S to 70' sl. In this paper we report on a preliminary analysis of images of low northern and southern latitudes including Alpha Regio, eastern Beta Regio, and dark-halo features in the lowland plains of Guinevere Planitia. Crater distributions and the locations of the Venera 9 and 10 landing sites are also examined. Al~haReeio; (So, 25" S) is a 1000 x 1600 km upland region located south of Pioneer-Venus and Venera 15-16 radar image coverage. It was the first area of anomalously high radar return discovered in the early 1960's by Earth- based radars (hence the name). Recent comparisons of Pioneer-Venus altirnetry, reflectivity and r.m.s. slope data with different terrain types apparent in the Venera 15/16 images indicate that Alpha Regio has many similarities with te~sera~-~.The new high resolution images (Fig.
    [Show full text]