DOCSLIB.ORG

Geology of the Common Mouth of the Ares and Tiu Valles, Mars A

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geology of the Common Mouth of the Ares and Tiu Valles, Mars A Sotar Synm Rntaidt. ^iL 33. Ne. 6,199Í, pp. 41S-4S2. Tmalaudinm AitnmaidditMi Kimli^ Hit 31. No. 6. Í99S, pp. 4SJ~SI}. Origbul Kuiiiai Ttn Cepyrífht O 1993 by Marthnko. Baiiitvsky, Hoffmaa\, Haniítii CooL Ntnhm. Geology of the Common Mouth of the Ares and Tiu Valles, Mars A. G. Marchenko*» A. T. BasUevsky*, R Hoftinann**, E. Hfluber**, A. C. Cook***, and G. Neukum** • Vemadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, ul. Kosygina ¡9, Moscow, ¡17975 Russia ** DLR Institute of Planetary Exploration, 12489 Berlin, Gerrriany *** Center cf Earth and Planetary Studies, National Air and Space Museum, ^¥askinglon. DC, USA Received June 23, 1998 Abstract•Since the Mars Paif^nder landing site is located at the mouth of the Ares and Tiu valles, this region attracts keen scientific interest. In order to better undcretand experinienta] data ffom this small area of the sur- face of Mars, which has been iavesti|ated by the rover, and the properties of the malciials occurring here, it is necessary to answer how, from where, and when this material was transponed. To answer these questions, we performed photogeological mapping and counted impact craterin the region. A photogeological analysis of 320 TV images of the studied area, thermal-inertia maps, and digital elevahon models were used in mapping. Our results, and those published by other scientists, allow us to distinguish several principal stages in the geological history of Üie mouth of the Ares and Tiu valles: the destruction stage of an ancient plateau and three stages of fluvial activity. Deposits transported by water flows to the Mars Pathfinder landing site presumably consist of fragments of the material of ancient Martian highlands (impact breccias and lavas), of younger sedimentary or volcano-sedimentary material of ridged plains, of impact-crater materials, and of eoUan products. The main constituents should be as old as approximaxely 4 Gyr (highland materials) and 3.5 Gyr (ridged-plain materials). It is very hkely that the fluvial reworking of this ancient material took place between 3.6 and 2.6 Gyr ago and, possibly, even lattr, between 2,3 and ) .4 Gyr ago. 1. INTRODUCTION lack of drainage basins related to outöow valleys exclude this mechanism for their formation. Glacier 1.1. Martian Outflow Valleys movements represent another process forming valley- In 1970, images obtained by Aionnej'9revealed val- shaped landfonns on the Eaith. Some researchers (Luc- leys on the Martian surface, which are similar in mor- chittaeio/., 1981; Lucchitta, 1982; Kai^cle/a/., 1995) phology to valleys and dry river channels on the Earth believe this prtwess was similarly responsible for the (McCauley et al., 1972). The similarity is, however, origin of the Martian outflow valleys. However, gla- incomplete; for example, many Martian valleys, in con- ciers of the Earth usually move along the fluvial (water- trast to their terrestrial counterparts, lack drainage formed) valleys, transforming them into glacial troughs basins. Several morphological varieties of Martian vaJ- (Hamblin, 1975). In addition, the growth, movement, leys, such as valley networks, outflow valleys, runoff and thawing (tHit not evaporation) of glaciers can pro- valleys, and ñttted valleys, are distinguished (Sharp ceed under terrestrial, but not under Martian atmo- and Malin, 1975; Carr. 1996). The Arcs and Tiu valles spheric conditions. studied in this work are of the outflow-vallQr class. According to some scientific ideas, a possible alter- About 15 Martian valleys of this class are known at native is the catastrophic (geologically instantaneous) present (Baker, 1982); they all arc large (up to several origin of outflow valleys, which was so quick that there thousand kilometers long) and almost completely lack- was no time for water evaporation. In this case, we ing in tributaries. In the recent geological epoch, water should assume an instantaneous release of a huge vol- on Mars' surface could exist only in the form of ice and ume of water. vapor, because the atmospheric pressure at the planet The outflow valleys could have been formed as a surfte is only 5-10 mb. The outflow valleys were consequence of catastrophic outflows of groimd water foimed 3,6-0.5 Gyr ago after a period of heavy nveieor- to the surface (Baker and Milton, 1974; Baker and itic bombardment, when atmospheric conditions were Kochel, 1978; Carr, 1979). There is evidence for the most likely similar to the cuiient state (Masursky et al., idea that the Martian lithosphère may include horizons 1977; Scott et al., 1979; Wise et al., 1979; Baker and saturated with ice or water (see, for instance, Kuz'min, Kochel. 1979). 1980). The morphology of head areas of outflow val- Large river valleys on the Earth evolve over millions leys is indicative of plentiful sinkholes. Several pro- of years, mainly under the control of atmospheric pre- cesses could provoke water outflows on the surface. cipitation. Environments at the surface of Mars and the According to a hypothesis by Carr (1979), this was a 0038-0946/98/32O&0425$20.0O O 1998 MAHK Hayu/lnteiperiodica Publishing 426 MARCHENKO et al. pressure increase in water-bearing horizons due to 1.3. Data Used and Investigation Methods freezing. Some scientists (McCauley et ai, 1972; Masursky et ai, 1977) assume water discharge to be a Geological mapping was performed using the pho- result of the thawing of pennafrost under the influence togeological analysis of TV images and some other of gcothermai heating. Others believe that outflow val- data (Marchenko, 1996; Marchenko etal., 1996, 1997, leys and their deposits were formed by the movement 1998). We used 320 images in the visible spectrum of a substance rich in solid material, resembling mud range obtained by the Viking Orbiter, thermal-inertia flows or laharï (Nunrunedal and Prior, 1981; Tanaka, and rock-abundance maps compiled on the basis of the 1988, 1997). thermal-mapping data obtained by this spacecraft Features similar to the Martian outflow valleys aie well (Christcnsen. 1986; Christensen and Kieffer, 1989; known on the Earth (Milton, 1973; McCauley tí al., Edgett and Christensen, 1997), along with a color 1972). They are relatcid in origin to catastrophic water mosaic of the images shot by this spacecraft through release ftom glacier-dammed lakes (Bretz et at., 1956; various photo-filters. The resolution of the Wang Bretz, 1969; Butvilovskii, 1993; Rudoi, 1995) and to images is 36-821 m per pixel. The resolution of the ice thawing in response to volcanic eruptions under gla- themial-mapping data used in this smdy is 30 km. In ciers (e.g.. Thorarinsson. 1957). These geomorpholog- addition, a semiautomatic analysis of stereoscopic ical features are rare terrestrial counterparts of the Mar- images (Thomhill et al., 1993) was used to construct tian outflow valleys, although the water-discharge val- topographic maps of several areas and to evaluate the ues in the last case should be 10-100 times greater altitudes of some relief features. When the distin- (Baker and Milton. 1974; Baker, 1982). guished age (stratigraphie) units of the surface were marked by a statistically significant number of impact craters, their calculated density was used to check the J.2. What is Stimulating Interest in the Mouth age interpretation. The impact-crater count was per- of the Ares and Tiu Valles? formed on the basis of 55 images. Whatever the formation mechanism of outflow val- In our studies, we refer to the global and regional leys•in particular, the Ares and Tiu•was {cata- stratign^hy of Mars elaborated recently by other strophic fluvial, related to mudflows, or glacial), it researchers. Scon and Carr (1978) were first to recog- obviously might involve the transport of the materials nize three major stratigraphic-age units of this planet: derived from geologically different regions of Mars cut Noachian (ancient), Hesperian (middle), and Amazo- by these valleys to the mouth of the flows. The Ares and nian (young). They also evaluated the crater densities Tiu valles begin in regions with a chaotic morphology characteristic of these units. The absolute age of the of the ground-collapse type, then they run across an ancient, heavily cratered highland region, and finally units is a point of controversy. Neukum and Wise open to the lower-laying Chryse Planitia, where they (1976) defined the ages of the Noachian-Hesperian and merge (Fig. la). Each of these valleys is about 1500 km the Hesperian-Anuzonian boundaries as 3.8 and 3.6 Gyr, long and 25-100 km wide. Thus, they are as long as the whereas Hartmann et al, (1981) suggest that they are largest rivers of the Earth, e.g., the Amazon River, but 3,5 and 1.8 Gyr old, respectively. are notably wider. Moreover, processes unrelated to the A map by Scott and Tanaka ( 1986), comprising the valley origin proper could also operate in their common region under discussion, was used as a basis for our mouth, being responsible for the influx of various mate- more detailed mapping. This map depicts more detailed rials, e.g., for sedimentation in temporary lakes and sea stratigraphie subdivisions than that of Scott and Carr basins (Parker et al., 1989, 1993; Baker et al., 1991; (1978), and each of the units is characterized by its Scottí/fl/., 1991;Craddockrto/.. 1997), eolian accu- impact-ciater density. In our study, we distinguished mulation (Kuzmin and Greeley, 1995a, 1995b), subse- several new stratigraphie units missing in the map by quent lava eruptions (Robinson et al.. 1996). and later mudflows (Jons, 1984), Scott and Tanaka (1986) and suggested a new interpre- tation to some others recognized before. Most detailed The high probability of detecting diverse geological among the geological-geomorphologic maps compris- materials in the Ares/Tiu mouth was the main reason ing the studied region is that of Rotto and Tanaka for choosing this area for a detailed study with a niKxl- (1995), although the stratigraphie and morphologic erate-sized rover brought by Mars Pathfinder units of valley floors and eolian deposits, especially (Golombek et aL, 1995, 1997b).
Load more

Recommended publications
  • Thermal Studies of Martian Channels and Valleys Using Termoskan Data
    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 99, NO. El, PAGES 1983-1996, JANUARY 25, 1994 Thermal studiesof Martian channelsand valleys using Termoskan data BruceH. Betts andBruce C. Murray Divisionof Geologicaland PlanetarySciences, California Institute of Technology,Pasadena The Tennoskaninstrument on boardthe Phobos '88 spacecraftacquired the highestspatial resolution thermal infraredemission data ever obtained for Mars. Included in thethermal images are 2 km/pixel,midday observations of severalmajor channel and valley systems including significant portions of Shalbatana,Ravi, A1-Qahira,and Ma'adimValles, the channelconnecting Vailes Marineris with HydraotesChaos, and channelmaterial in Eos Chasma.Tennoskan also observed small portions of thesouthern beginnings of Simud,Tiu, andAres Vailes and somechannel material in GangisChasma. Simultaneousbroadband visible reflectance data were obtainedfor all but Ma'adimVallis. We find thatmost of the channelsand valleys have higher thermal inertias than their surroundings,consistent with previousthermal studies. We show for the first time that the thermal inertia boundariesclosely match flat channelfloor boundaries.Also, butteswithin channelshave inertiassimilar to the plainssurrounding the channels,suggesting the buttesare remnants of a contiguousplains surface. Lower bounds ontypical channel thermal inertias range from 8.4 to 12.5(10 -3 cal cm-2 s-1/2 K-I) (352to 523 in SI unitsof J m-2 s-l/2K-l). Lowerbounds on inertia differences with the surrounding heavily cratered plains range from 1.1 to 3.5 (46 to 147 sr). Atmosphericand geometriceffects are not sufficientto causethe observedchannel inertia enhancements.We favornonaeolian explanations of the overall channel inertia enhancements based primarily upon the channelfloors' thermal homogeneity and the strongcorrelation of thermalboundaries with floor boundaries. However,localized, dark regions within some channels are likely aeolian in natureas reported previously.
    [Show full text]
  • Minimum Dietary Diversity for Women a Guide to Measurement
    FANTA III FOOD AND NUTRITION TECHNICAL A SSISTANCE Minimum Dietary Diversity for Women A Guide to Measurement Minimum Dietary Diversity for Women A Guide to Measurement Published by the Food and Agriculture Organization of the United Nations and USAID’s Food and Nutrition Technical Assistance III Project (FANTA), managed by FHI 360 Rome, 2016 Recommended citation: FAO and FHI 360. 2016. Minimum Dietary Diversity for Women: A Guide for Measurement. Rome: FAO. The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations (FAO), or of FANTA/FHI 360 concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or products of manufacturers, whether or not these have been patented, does not imply that these have been endorsed or recommended by FAO, or FHI 360 in preference to others of a similar nature that are not mentioned. Additional funding for this publication was made possible by the generous support of the American people through the support of the Office of Health, Infectious Diseases, and Nutrition, Bureau for Global Health, U.S. Agency for International Development (USAID), under terms of Cooperative Agreement AID-OAA-A-12-00005 through the Food and Nutrition Technical Assistance III Project (FANTA), managed by FHI 360. The views expressed in this information product are those of the author(s) and do not necessarily reflect the views or policies of FAO, FHI 360, UC Davis, USAID or the U.S.
    [Show full text]
  • The History Group's Silver Jubilee
    History of Meteorology and Physical Oceanography Special Interest Group Newsletter 1, 2010 ANNUAL REPORT CONTENTS We asked in the last two newsletters if you Annual Report ........................................... 1 thought the History Group should hold an Committee members ................................ 2 Annual General Meeting. There is nothing in Mrs Jean Ludlam ...................................... 2 the By-Law s or Standing Orders of the Royal Meteorological Society that requires the The 2010 Summer Meeting ..................... 3 Group to hold one, nor does Charity Law Report of meeting on 18 November .......... 4 require one. Which papers have been cited? .............. 10 Don’t try this at home! ............................. 10 Only one person responded, and that was in More Richard Gregory reminiscences ..... 11 passing during a telephone conversation about something else. He was in favour of Storm warnings for seafarers: Part 2 ....... 13 holding an AGM but only slightly so. He Swedish storm warnings ......................... 17 expressed the view that an AGM provides an Rikitea meteorological station ................. 19 opportunity to put forward ideas for the More on the D-Day forecast .................... 20 Group’s committee to consider. Recent publications ................................ 21 As there has been so little response, the Did you know? ........................................ 22 Group’s committee has decided that there will Date for your diary .................................. 23 not be an AGM this year. Historic picture ........................................ 23 2009 members of the Group ................... 24 CHAIRMAN’S REVIEW OF 2009 by Malcolm Walker year. Sadly, however, two people who have supported the Group for many years died during I begin as I did last year. Without an enthusiastic 2009. David Limbert passed away on 3 M a y, and conscientious committee, there would be no and Jean Ludlam died in October (see page 2).
    [Show full text]
  • Tentative Lists Submitted by States Parties As of 15 April 2021, in Conformity with the Operational Guidelines
    World Heritage 44 COM WHC/21/44.COM/8A Paris, 4 June 2021 Original: English UNITED NATIONS EDUCATIONAL, SCIENTIFIC AND CULTURAL ORGANIZATION CONVENTION CONCERNING THE PROTECTION OF THE WORLD CULTURAL AND NATURAL HERITAGE WORLD HERITAGE COMMITTEE Extended forty-fourth session Fuzhou (China) / Online meeting 16 – 31 July 2021 Item 8 of the Provisional Agenda: Establishment of the World Heritage List and of the List of World Heritage in Danger 8A. Tentative Lists submitted by States Parties as of 15 April 2021, in conformity with the Operational Guidelines SUMMARY This document presents the Tentative Lists of all States Parties submitted in conformity with the Operational Guidelines as of 15 April 2021. • Annex 1 presents a full list of States Parties indicating the date of the most recent Tentative List submission. • Annex 2 presents new Tentative Lists (or additions to Tentative Lists) submitted by States Parties since 16 April 2019. • Annex 3 presents a list of all sites included in the Tentative Lists of the States Parties to the Convention, in alphabetical order. Draft Decision: 44 COM 8A, see point II I. EXAMINATION OF TENTATIVE LISTS 1. The World Heritage Convention provides that each State Party to the Convention shall submit to the World Heritage Committee an inventory of the cultural and natural sites situated within its territory, which it considers suitable for inscription on the World Heritage List, and which it intends to nominate during the following five to ten years. Over the years, the Committee has repeatedly confirmed the importance of these Lists, also known as Tentative Lists, for planning purposes, comparative analyses of nominations and for facilitating the undertaking of global and thematic studies.
    [Show full text]
  • Imagining Outer Space Also by Alexander C
    Imagining Outer Space Also by Alexander C. T. Geppert FLEETING CITIES Imperial Expositions in Fin-de-Siècle Europe Co-Edited EUROPEAN EGO-HISTORIES Historiography and the Self, 1970–2000 ORTE DES OKKULTEN ESPOSIZIONI IN EUROPA TRA OTTO E NOVECENTO Spazi, organizzazione, rappresentazioni ORTSGESPRÄCHE Raum und Kommunikation im 19. und 20. Jahrhundert NEW DANGEROUS LIAISONS Discourses on Europe and Love in the Twentieth Century WUNDER Poetik und Politik des Staunens im 20. Jahrhundert Imagining Outer Space European Astroculture in the Twentieth Century Edited by Alexander C. T. Geppert Emmy Noether Research Group Director Freie Universität Berlin Editorial matter, selection and introduction © Alexander C. T. Geppert 2012 Chapter 6 (by Michael J. Neufeld) © the Smithsonian Institution 2012 All remaining chapters © their respective authors 2012 All rights reserved. No reproduction, copy or transmission of this publication may be made without written permission. No portion of this publication may be reproduced, copied or transmitted save with written permission or in accordance with the provisions of the Copyright, Designs and Patents Act 1988, or under the terms of any licence permitting limited copying issued by the Copyright Licensing Agency, Saffron House, 6–10 Kirby Street, London EC1N 8TS. Any person who does any unauthorized act in relation to this publication may be liable to criminal prosecution and civil claims for damages. The authors have asserted their rights to be identified as the authors of this work in accordance with the Copyright, Designs and Patents Act 1988. First published 2012 by PALGRAVE MACMILLAN Palgrave Macmillan in the UK is an imprint of Macmillan Publishers Limited, registered in England, company number 785998, of Houndmills, Basingstoke, Hampshire RG21 6XS.
    [Show full text]
  • IN-SITU RADIOMETRIC AGE DETERMINATION: a CRITICAL COMPONENT of MARS EXPLORATION. J. B. Plescia1 and T. D. Swindle2, 1Applied
    Seventh International Conference on Mars 3278.pdf IN-SITU RADIOMETRIC AGE DETERMINATION: A CRITICAL COMPONENT OF MARS EXPLORATION. J. B. Plescia1 and T. D. Swindle2, 1Applied Physics Laboratory, Johns Hopkins University, 11100 Johns Hopkins Road, Laurel, MD 20723, [email protected]. 2Department of Planetary Sciences, Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, [email protected]. Introduction: In order to understand the geologic, Bombardment [12-18], although this remains a contro- climatic and possibly the biologic evolution of Mars, versial topic. It has also been suggested that the crater- the absolute timing of events must be established. ing rate over the last several billion years has not been Questions of climate change, glacial processes, avail- uniform, but rather has been punctuated by periodic ability of surface water, recent volcanism, and atmos- spikes in the rate [19-20]. pheric evolution all hinge on determining when those events occurred in absolute time. Resolving the abso- lute timing of events has become even more critical with the suggestions of currently active glacial and perhaps fluvial activity and very young volcanic activ- ity. Background: To date, only the relative chronology of events has been firmly established [1]. This has been accomplished through the use of impact crater counts in which the frequency of impact craters per unit area greater than or equal to some diameter is used as a reference for comparison among surfaces; the higher the frequency, the older the age [2-3]. This technique allows surfaces and events on different parts of a planet to be correlated in time.
    [Show full text]
  • The 1997 Mars Pathfinder Spacecraft Landing Site: Spillover Deposits
    www.nature.com/scientificreports OPEN The 1997 Mars Pathfnder Spacecraft Landing Site: Spillover Deposits from an Early Mars Inland Sea Received: 13 June 2018 J. A. P. Rodriguez1, V. R. Baker2, T. Liu 2, M. Zarroca3, B. Travis1, T. Hui2, G. Komatsu 4, Accepted: 22 January 2019 D. C. Berman1, R. Linares3, M. V. Sykes1, M. E. Banks1,5 & J. S. Kargel1 Published: xx xx xxxx The Martian outfow channels comprise some of the largest known channels in the Solar System. Remote-sensing investigations indicate that cataclysmic foods likely excavated the channels ~3.4 Ga. Previous studies show that, in the southern circum-Chryse region, their fooding pathways include hundreds of kilometers of channel foors with upward gradients. However, the impact of the reversed channel-foor topography on the cataclysmic foods remains uncertain. Here, we show that these channel foors occur within a vast basin, which separates the downstream reaches of numerous outfow channels from the northern plains. Consequently, foods propagating through these channels must have ponded, producing an inland sea, before reaching the northern plains as enormous spillover discharges. The resulting paleohydrological reconstruction reinterprets the 1997 Pathfnder landing site as part of a marine spillway, which connected the inland sea to a hypothesized northern plains ocean. Our food simulation shows that the presence of the sea would have permitted the propagation of low-depth foods beyond the areas of reversed channel-foor topography. These results explain the formation at the landing site of possible fuvial features indicative of fow depths at least an order of magnitude lower than those apparent from the analyses of orbital remote-sensing observations.
    [Show full text]
  • CARES ACT GRANT AMOUNTS to AIRPORTS (Pursuant to Paragraphs 2-4) Detailed Listing by State, City and Airport
    CARES ACT GRANT AMOUNTS TO AIRPORTS (pursuant to Paragraphs 2-4) Detailed Listing By State, City And Airport State City Airport Name LOC_ID Grand Totals AK Alaskan Consolidated Airports Multiple [individual airports listed separately] AKAP $16,855,355 AK Adak (Naval) Station/Mitchell Field Adak ADK $30,000 AK Akhiok Akhiok AKK $20,000 AK Akiachak Akiachak Z13 $30,000 AK Akiak Akiak AKI $30,000 AK Akutan Akutan 7AK $20,000 AK Akutan Akutan KQA $20,000 AK Alakanuk Alakanuk AUK $30,000 AK Allakaket Allakaket 6A8 $20,000 AK Ambler Ambler AFM $30,000 AK Anaktuvuk Pass Anaktuvuk Pass AKP $30,000 AK Anchorage Lake Hood LHD $1,053,070 AK Anchorage Merrill Field MRI $17,898,468 AK Anchorage Ted Stevens Anchorage International ANC $26,376,060 AK Anchorage (Borough) Goose Bay Z40 $1,000 AK Angoon Angoon AGN $20,000 AK Aniak Aniak ANI $1,052,884 AK Aniak (Census Subarea) Togiak TOG $20,000 AK Aniak (Census Subarea) Twin Hills A63 $20,000 AK Anvik Anvik ANV $20,000 AK Arctic Village Arctic Village ARC $20,000 AK Atka Atka AKA $20,000 AK Atmautluak Atmautluak 4A2 $30,000 AK Atqasuk Atqasuk Edward Burnell Sr Memorial ATK $20,000 AK Barrow Wiley Post-Will Rogers Memorial BRW $1,191,121 AK Barrow (County) Wainwright AWI $30,000 AK Beaver Beaver WBQ $20,000 AK Bethel Bethel BET $2,271,355 AK Bettles Bettles BTT $20,000 AK Big Lake Big Lake BGQ $30,000 AK Birch Creek Birch Creek Z91 $20,000 AK Birchwood Birchwood BCV $30,000 AK Boundary Boundary BYA $20,000 AK Brevig Mission Brevig Mission KTS $30,000 AK Bristol Bay (Borough) Aleknagik /New 5A8 $20,000 AK
    [Show full text]
  • U.S. Government Printing Office Style Manual, 2008
    U.S. Government Printing Offi ce Style Manual An official guide to the form and style of Federal Government printing 2008 PPreliminary-CD.inddreliminary-CD.indd i 33/4/09/4/09 110:18:040:18:04 AAMM Production and Distribution Notes Th is publication was typeset electronically using Helvetica and Minion Pro typefaces. It was printed using vegetable oil-based ink on recycled paper containing 30% post consumer waste. Th e GPO Style Manual will be distributed to libraries in the Federal Depository Library Program. To fi nd a depository library near you, please go to the Federal depository library directory at http://catalog.gpo.gov/fdlpdir/public.jsp. Th e electronic text of this publication is available for public use free of charge at http://www.gpoaccess.gov/stylemanual/index.html. Use of ISBN Prefi x Th is is the offi cial U.S. Government edition of this publication and is herein identifi ed to certify its authenticity. ISBN 978–0–16–081813–4 is for U.S. Government Printing Offi ce offi cial editions only. Th e Superintendent of Documents of the U.S. Government Printing Offi ce requests that any re- printed edition be labeled clearly as a copy of the authentic work, and that a new ISBN be assigned. For sale by the Superintendent of Documents, U.S. Government Printing Office Internet: bookstore.gpo.gov Phone: toll free (866) 512-1800; DC area (202) 512-1800 Fax: (202) 512-2104 Mail: Stop IDCC, Washington, DC 20402-0001 ISBN 978-0-16-081813-4 (CD) II PPreliminary-CD.inddreliminary-CD.indd iiii 33/4/09/4/09 110:18:050:18:05 AAMM THE UNITED STATES GOVERNMENT PRINTING OFFICE STYLE MANUAL IS PUBLISHED UNDER THE DIRECTION AND AUTHORITY OF THE PUBLIC PRINTER OF THE UNITED STATES Robert C.
    [Show full text]
  • Orbital Evidence for More Widespread Carbonate- 10.1002/2015JE004972 Bearing Rocks on Mars Key Point: James J
    PUBLICATIONS Journal of Geophysical Research: Planets RESEARCH ARTICLE Orbital evidence for more widespread carbonate- 10.1002/2015JE004972 bearing rocks on Mars Key Point: James J. Wray1, Scott L. Murchie2, Janice L. Bishop3, Bethany L. Ehlmann4, Ralph E. Milliken5, • Carbonates coexist with phyllosili- 1 2 6 cates in exhumed Noachian rocks in Mary Beth Wilhelm , Kimberly D. Seelos , and Matthew Chojnacki several regions of Mars 1School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA, 2The Johns Hopkins University/Applied Physics Laboratory, Laurel, Maryland, USA, 3SETI Institute, Mountain View, California, USA, 4Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA, 5Department of Geological Sciences, Brown Correspondence to: University, Providence, Rhode Island, USA, 6Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona, USA J. J. Wray, [email protected] Abstract Carbonates are key minerals for understanding ancient Martian environments because they Citation: are indicators of potentially habitable, neutral-to-alkaline water and may be an important reservoir for Wray, J. J., S. L. Murchie, J. L. Bishop, paleoatmospheric CO2. Previous remote sensing studies have identified mostly Mg-rich carbonates, both in B. L. Ehlmann, R. E. Milliken, M. B. Wilhelm, Martian dust and in a Late Noachian rock unit circumferential to the Isidis basin. Here we report evidence for older K. D. Seelos, and M. Chojnacki (2016), Orbital evidence for more widespread Fe- and/or Ca-rich carbonates exposed from the subsurface by impact craters and troughs. These carbonates carbonate-bearing rocks on Mars, are found in and around the Huygens basin northwest of Hellas, in western Noachis Terra between the Argyre – J.
    [Show full text]
  • Salt Triggered Melting of Permafrost in the Chaos Regions of Mars
    Lunar and Planetary Science XXXVII (2006) 2218.pdf SALT TRIGGERED MELTING OF PERMAFROST IN THE CHAOS REGIONS OF MARS. Popa I.C., Università degli Studi "G. d'Annunzio" Chieti-Pescara, Pescara, Viale Pindaro 42, Italy. ([email protected]) Introduction: Mars surface bears traces of many landing site (Chryse Planitia) is the place where Ares fluvial-like features, geomorphic identified as outflow outflow channel is depositing its transporting channels, valley networks etc. Among these a particular materials. The following Martian landers Pathfinder one stands above others from the dimensional point of [6] and MER A Spirit [7], and MER B Opportunity [8] view. Outflow channels bear unique water erosion also revealed high soluble salts contents in places characteristics, that led Baker and Milton (1974) [1] to possibly genetically connected. Recently OMEGA believe that are caused by a surface runoff of large aboard Mars Express spacecraft has proven the amounts of water, in short geological time. Water existence of gypsum and other highly soluble salts (e.g origin, necessary for these processes was the topic of kieserite and epsomite) in localized deposits in places around Valles Marineris, and Iani Chaos [9]. many works. Among these theories one generally Freezing point depression of water solutions: accepted idea considers that water is originating from The freezing point of pure water at 1 bar is 0°C melting of permafrost layers positioned in the places of (273K). This melting point can be easily depressed by today chaos’. Here is an investigation that takes into adding impurities or soluble salts to the solvent. In the account the exoergic salt-ice dissolution reaction, along case of halite (NaCl) salt it is known that a 10% NaCl with freezing point depression of formed salty solutions, solution lowers the melting point of about -6°C (267K) as a complentary or a stand-alone process in chaos- and a 20% salt solution lowers it to -16°C (257K).
    [Show full text]
  • Download Student Activities Objects from the Area Around Its Orbit, Called Its Orbital Zone; at Amnh.Org/Worlds-Beyond-Earth-Educators
    INSIDE Essential Questions Synopsis Missions Come Prepared Checklist Correlation to Standards Connections to Other Halls Glossary ONLINE Student Activities Additional Resources amnh.org/worlds-beyond-earth-educators EssentialEssential Questions Questions What is the solar system? In the 20th century, humans began leaving Earth. NASA’s Our solar system consists of our star—the Sun—and all the Apollo space program was the first to land humans on billions of objects that orbit it. These objects, which are bound another world, carrying 12 human astronauts to the Moon’s to the Sun by gravity, include the eight planets—Mercury, surface. Since then we’ve sent our proxies—robots—on Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; missions near and far across our solar system. Flyby several dwarf planets, including Ceres and Pluto; hundreds missions allow limited glimpses; orbiters survey surfaces; of moons orbiting the planets and other bodies, including landers get a close-up understanding of their landing Jupiter’s four major moons and Saturn’s seven, and, of course, location; and rovers, like human explorers, set off across the Earth’s own moon, the Moon; thousands of comets; millions surface to see what they can find and analyze. of asteroids; and billions of icy objects beyond Neptune. The solar system is shaped like a gigantic disk with the Sun at The results of these explorations are often surprising. With its center. Everywhere we look throughout the universe we the Moon as our only reference, we expected other worlds see similar disk-shaped systems bound together by gravity. to be cold, dry, dead places, but exploration has revealed Examples include faraway galaxies, planetary systems astonishing variety in our solar system.
    [Show full text]