DOCSLIB.ORG

Active Dust Devils on Mars

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Active Dust Devils on Mars ACTIVE DUST DEVILS ON MARS: A COMPARISON OF SIX SPACECRAFT LANDING SITES by Devin Waller A Thesis Presented in Partial Fulfillment of the Requirements for the Degree Master of Science Approved April 2011 by the Graduate Supervisory Committee: Ronald Greeley, Chair Philip Christensen Randall Cerveny ARIZONA STATE UNIVERSITY May 2011 ABSTRACT Dust devils have proven to be commonplace on Mars, although their occurrence is unevenly distributed across the surface. They were imaged or inferred by all six successful landed spacecraft: the Viking 1 and 2 Landers (VL-1 and VL-2), Mars Pathfinder Lander, the Mars Exploration Rovers Spirit and Opportunity, and the Phoenix Mars Lander. Comparisons of dust devil parameters were based on results from optical and meteorological (MET) detection campaigns. Spatial variations were determined based on comparisons of their frequency, morphology, and behavior. The Spirit data spanning three consecutive martian years is used as the basis of comparison because it is the most extensive on this topic. Average diameters were between 8 and 115 m for all observed or detected dust devils. The average horizontal speed for all of the studies was roughly 5 m/s. At each site dust devil densities peaked between 09:00 and 17:00 LTST during the spring and summer seasons supporting insolation-driven convection as the primary formation mechanism. Seasonal number frequency averaged ~1 dust devils/ km2/sol and spanned a total of three orders of magnitude. Extrapolated number frequencies determined for optical campaigns at the Pathfinder and Spirit sites accounted for temporal and spatial inconsistencies and averaged ~19 dust devils/km2/sol. Dust fluxes calculated from Pathfinder data (5x10-4 kg/m2/s and 7x10-5 kg/m2/s) were well with in the ranges calculated from Spirit data (4.0x10-9 to 4.6x10-4 kg/m2/s for Season One, 5.2x10-7 to 6.2x10-5 kg/m2/s during Season Two, and 1.5x10-7 to 1.6x10-4 kg/m2/s during Season Three). Based on the results a campaign is written for improvements in dust devil i detection at the Mars Science Laboratory's (MSL) site. Of the four remaining candidate MSL sites, the dusty plains of Gale crater may potentially be the site with the highest probability of dust devil activity. ii DEDICATION I dedicate this accomplishment to my mother, Linda Watts, who has stood by my side every step of this process. Without her love, understanding, endless support, and guidance this journey would have been significantly more difficult. I thank her for leading by example and always reminding me to stay positive. Thanks to her I’ve remained steadfast in my persistence to finish my graduate degree. I look forward to a very bright future. iii ACKNOWLEDGMENTS It is my pleasure to thank those who made this thesis possible. I owe my deepest gratitude to Ronald Greeley who has served as my professor, advisor, and chairman of my supervisory committee. I thank him for the academic opportunities he has provided, for the guidance and advice that he has given, and for the many discussions we have had that have assisted me throughout this process. I especially thank him for allowing me the opportunity to work in active mission operations as a geology theme lead on the Mars Exploration Rover project. I am grateful to my committee members Phil Christensen and Randy Cervany for their insightful discussions that have helped improve my general understanding of aeolian processes that occur on Mars and Earth. The foundation of this thesis would not have been possible without the hours of discussion had with my colleagues Shane Thompson, Lynn Neakrase and Patrick Whelley. I would also like to thank Charles Bradbury whose technical assistance and advice were invaluable. I would like to acknowledge my fellow Planetary Geology Group members and graduate students for their support and advice throughout this process. Last, but certainly not least, I am grateful for my family and friends who were always there for me during the writing of this thesis. iv TABLE OF CONTENTS Page LIST OF TABLES .....................................................................................................vi LIST OF FIGURES...................................................................................................vii CHAPTER 1 INTRODUCTION............................................................................ 1 1.1 Background...............................................................................................1 1.1.1 Dust in the Martian Atmosphere ................................................1 1.1.2 Formation of Dust Devils on Mars.............................................6 1.1.3 Detection of Dust Devils with Landed Spacecraft...................11 1.2 Objective of Study ..................................................................................15 CHAPTER 2 LANDING SITE OVERVIEW...................................................... 17 2.1 Chapter Overview...................................................................................17 2.2 Instruments Used in Dust Devil and Vortex Detection..........................17 2.3 Landing Sites ..........................................................................................30 2.3.1 Viking Lander 1 ........................................................................30 2.3.2 Viking Lander 2 ........................................................................35 2.3.3 Mars Pathfinder Lander ............................................................39 2.3.4 Mars Exploration Rover Spirit..................................................45 2.3.5 Mars Exploration Rover Opportunity.......................................51 2.3.6 Phoenix Mars Lander................................................................54 CHAPTER 3 COMPARISONS AND RESULTS ............................................... 59 3.1 Chapter Overview...................................................................................59 3.2 Landing Site Characteristics...................................................................59 v 3.3 Dust Devil Morphology..........................................................................63 3.4 Dust Devil Speeds...................................................................................76 3.5 Diurnal and Seasonal Frequency............................................................81 3.6 Number Frequency .................................................................................94 3.7 Dust Flux.................................................................................................98 3.8 Dust Loading.........................................................................................100 CHAPTER 4 DISCUSSION AND PREDICTIONS ......................................... 101 4.1 Discussion ............................................................................................101 4.2 Mars Science Laboratory......................................................................104 4.2.1 MSL Dust Devil Detection Campaign ...................................107 4.2.2 Candidate Landing Sites and Predictions...............................109 REFERENCES ...................................................................................................... 114 vi LIST OF TABLES Table Page 2.1 Mission operation dates, total sols, locations, and coordinates .................. 17 2.2 Optical instruemnts used in dust devil detection ........................................ 19 2.3 Meteorological instruemnts used in vortex detection ................................. 20 3.1 Rock abundance chart ................................................................................. 61 3.2 TES thermal inertia and surface albedo ...................................................... 62 3.3 Range of dust devil diameters ..................................................................... 74 3.4 Range of dust devil speeds .......................................................................... 79 3.5 Number of vortices detected at the Viking Lander sites ............................ 90 3.6 Seasonal number frequencies ..................................................................... 97 3.7 Extrapolated number frequencies .............................................................. 98 4.1 Dust devil and vortex detection parameters ............................................. 109 vii LIST OF FIGURES Figure Page 1.1 Particle threshold curve ................................................................................. 4 1.2 Images of martian and terrestrial dust devils ................................................ 8 1.3 Forces on particle beneath passing vortex .................................................. 10 1.4 Rankine vortex model ................................................................................. 11 1.5 Map of spacecraft landing sites ................................................................... 13 1.6 Pressure, temperature, and wind vector perturbations ................................ 15 2.1 Schematic of Viking Lander detection instruments ................................... 23 2.2 Schematic of Mars Pathfinder Lander detection instruments .................... 25 2.3 Schematic of Mars Exploration Rover detection instruments .................... 28 2.4 Schematic of Phoenix Mars Lander detection instruments ........................ 29 2.5 Oribiter map of Viking Lander 1 site .......................................................... 32 2.6 Viking Lander 1 image of surrounding terrain ..........................................
Load more

Recommended publications
  • The Open University | Watch?V=Sk5tpzhhw50
    The Open University | watch?v=SK5tPzHHW50 [MUSIC PLAYING] KAREN FOLEY: So Jan Raack, welcome to the studio. What do you think of our audience's ideas? Aren't they creative? JAN RAACK: Of course, yes. So I joined the online chat a couple of minutes. KAREN FOLEY: I hear you've doing very well. JAN RAACK: Yeah, it was my first time-- KAREN FOLEY: Bringing some sense to the conversation, I hear. JAN RAACK: A little bit of science, yes, but not so much. Yes. KAREN FOLEY: No, that's brilliant. No, thank you. What's it like then for you? You're an academic at the Open University. You've been here not since very long. So you started here in March so it's all been quite new. What's it been like talking with-- and we've got a lot of science students out there. What's it been like as an academic then talking to everybody in this sort of environment? How have you found it? JAN RAACK: A little bit weird, to be honest, because I was a student a couple of years ago, too. And for me, it's a step further from students to ask questions-- to answer questions. So for me, it's really new and I am excited with it, really, and I enjoyed it. Yes. KAREN FOLEY: Excellent. You're now doing a lot of research. So you were from Germany and you've now come to the Open University here in sunny Milton Keynes. JAN RAACK: Sunny, yes. KAREN FOLEY: Well, not really, is it? We won't lie.
    [Show full text]
  • Martian Crater Morphology
    ANALYSIS OF THE DEPTH-DIAMETER RELATIONSHIP OF MARTIAN CRATERS A Capstone Experience Thesis Presented by Jared Howenstine Completion Date: May 2006 Approved By: Professor M. Darby Dyar, Astronomy Professor Christopher Condit, Geology Professor Judith Young, Astronomy Abstract Title: Analysis of the Depth-Diameter Relationship of Martian Craters Author: Jared Howenstine, Astronomy Approved By: Judith Young, Astronomy Approved By: M. Darby Dyar, Astronomy Approved By: Christopher Condit, Geology CE Type: Departmental Honors Project Using a gridded version of maritan topography with the computer program Gridview, this project studied the depth-diameter relationship of martian impact craters. The work encompasses 361 profiles of impacts with diameters larger than 15 kilometers and is a continuation of work that was started at the Lunar and Planetary Institute in Houston, Texas under the guidance of Dr. Walter S. Keifer. Using the most ‘pristine,’ or deepest craters in the data a depth-diameter relationship was determined: d = 0.610D 0.327 , where d is the depth of the crater and D is the diameter of the crater, both in kilometers. This relationship can then be used to estimate the theoretical depth of any impact radius, and therefore can be used to estimate the pristine shape of the crater. With a depth-diameter ratio for a particular crater, the measured depth can then be compared to this theoretical value and an estimate of the amount of material within the crater, or fill, can then be calculated. The data includes 140 named impact craters, 3 basins, and 218 other impacts. The named data encompasses all named impact structures of greater than 100 kilometers in diameter.
    [Show full text]
  • Field Measurements of Terrestrial and Martian Dust Devils Journal Item
    Open Research Online The Open University’s repository of research publications and other research outputs Field Measurements of Terrestrial and Martian Dust Devils Journal Item How to cite: Murphy, Jim; Steakley, Kathryn; Balme, Matt; Deprez, Gregoire; Esposito, Francesca; Kahanpää, Henrik; Lemmon, Mark; Lorenz, Ralph; Murdoch, Naomi; Neakrase, Lynn; Patel, Manish and Whelley, Patrick (2016). Field Measurements of Terrestrial and Martian Dust Devils. Space Science Reviews, 203(1) pp. 39–87. For guidance on citations see FAQs. c 2016 Springer https://creativecommons.org/licenses/by-nc-nd/4.0/ Version: Accepted Manuscript Link(s) to article on publisher’s website: http://dx.doi.org/doi:10.1007/s11214-016-0283-y Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online’s data policy on reuse of materials please consult the policies page. oro.open.ac.uk 1 Field Measurements of Terrestrial and Martian Dust Devils 2 Jim Murphy1, Kathryn Steakley1, Matt Balme2, Gregoire Deprez3, Francesca 3 Esposito4, Henrik Kahapää5, Mark Lemmon6, Ralph Lorenz7, Naomi Murdoch8, Lynn 4 Neakrase1, Manish Patel2, Patrick Whelley9 5 1-New Mexico State University, Las Cruces NM, USA 2 - Open University, Milton Keynes UK 6 3 - Laboratoire Atmosphères, Guyancourt, France 4 - INAF - Osservatorio Astronomico di 7 Capodimonte, Naples, Italy 5 - Finnish Meteorological Institute, Helsinki, Finland 6 - Texas 8 A&M University, College Station TX, USA 7 -Johns Hopkins University Applied Physics Lab, 9 Laurel MD USA 8 - ISAE-SUPAERO, Toulouse University, France 9 - NASA Goddard 10 Space Flight Center, Greenbelt MD, USA 11 submitted to SSR 10 May, 2016 12 Revised manuscript 08 August 2016 13 ABSTRACT 14 Surface-based measurements of terrestrial and martian dust devils/convective vortices 15 provided from mobile and stationary platforms are discussed.
    [Show full text]
  • Mars Exploration Rovers: 4 Years on Mars
    https://ntrs.nasa.gov/search.jsp?R=20080047431 2019-10-28T16:17:34+00:00Z Mars Exploration Rovers: 4 Years on Mars Geoffrey A. Landis This January, the Mars Exploration Rovers "Spirit" and "Opportunity" are starting their fifth year of exploring the surface of Mars, well over ten times their nominal 90-day design lifetime. This lecture discusses the Mars Exploration Rovers, presents the current mission status for the extended mission, some of the most results from the mission and how it is affecting our current view of Mars, and briefly presents the plans for the coming NASA missions to the surface of Mars and concepts for exploration with robots and humans into the next decade, and beyond. Four Years on Mars: the Mars Exploration Rovers Geoffrey A. Landis NASA John Glenn Research Center http://www.sff.net/people/geoffrey.landis Presentation at MIT Department of Aeronautics and Astronautics, January 18, 2008 Exploration - Landis Mars viewed from the Hubble Space Telescope Exploration - Landis Views of Mars in the early 20th century Lowell 1908 Sciaparelli 1888 Burroughs 1912 (cover painting by Frazetta) Tales of Outer Space ed. Donald A. Wollheim, Ace D-73, 1954 (From Winchell Chung's web page projectrho.com) Exploration - Landis Past Missions to Mars: first close up images of Mars from Mariner 4 Mariner 4 discovered Mars was a barren, moon-like desert Exploration - Landis Viking 1976 Signs of past water on Mars? orbiter Photo from orbit by the 1976 Viking orbiter Exploration - Landis Pathfinder and Sojourner Rover: a solar-powered mission
    [Show full text]
  • DRY (?) MARS: AEOLIAN PROCESSES, MASS WASTING, and ROCKS 7:00 P.M
    Lunar and Planetary Science XXXVI (2005) sess44.pdf Tuesday, March 15, 2005 POSTER SESSION I: DRY (?) MARS: AEOLIAN PROCESSES, MASS WASTING, AND ROCKS 7:00 p.m. Fitness Center Mullins K. F. Hayward R. K. Titus T. N. Bourke M. C. Fenton L. K. Mars Digital Dune Database: A Quantitative Look at the Geographic Distribution of Dunes on Mars [#1986] Initial steps in developing a digital dune database in a global geographic context for Mars have been completed. This database currently contains information delineating the dune fields between ±65 degrees latitude. Banks M. Bridges N. T. Benzit M. Measurements of the Coefficient of Restitution of Quartz Sand on Basalt: Implications for Abrasion Rates on Earth and Mars [#2116] Using high speed video to assess grain-rock interactions, it was found that the KE lost on impact is generally proportional to incoming velocity and impact angle, but that only a fraction of this energy goes into direct abrasion of the rock surface. Neakrase L. D. V. Greeley R. Williams D. A. Reiss D. Michaels T. I. Rafkin S. C. R. Neukum G. HRSC Team Hecates Tholus, Mars: Nighttime Aeolian Activity Suggested by Thermal Images and Mesoscale Atmospheric Model Simulations [#1898] Previously unidentified wind streaks identified on nighttime IR images on Hecates Tholus volcano on Mars agree with predictions of nighttime patterns by an atmospheric model, suggesting that nighttime winds are responsible for modifying the surface in contrast to afternoon winds. Neakrase L. D. V. Greeley R. Iversen J. D. Balme M. R. Foley D. J. Eddlemon E. E. Dust Devils on Mars: Effects of Surface Roughness on Particle Threshold [#1857] The aim of this study is to determine experimentally the effects of non-erodable roughness elements on vortex particle threshold through laboratory simulations of natural surfaces pertaining to dust devils on Earth and Mars.
    [Show full text]
  • Inferences of Martian Atmospheric Dust and Water Ice Content Derived from Radiative Transfer Models of Passive Msl Observations by Mastcam
    44th Lunar and Planetary Science Conference (2013) 1288.pdf INFERENCES OF MARTIAN ATMOSPHERIC DUST AND WATER ICE CONTENT DERIVED FROM RADIATIVE TRANSFER MODELS OF PASSIVE MSL OBSERVATIONS BY MASTCAM. E. M. McCul- lough1, J. E. Moores 1,2, R. Francis1, and the MSL Science Team. 1Centre for Planetary Science and Exploration (The University of Western Ontario, London, ON, Canada, [email protected]), 2Now at: Centre for Research in Earth and Space Sciences (CRESS, York University, Toronto, ON, Canada). Introduction: While the Mars Science Laboratory cameras [3]. The 440 nm and 750 nm combination of (MSL) Spacecraft was not designed primarily as a ve- wavelengths was chosen because this ratio is the least hicle from which to study the martian atmosphere, the ambiguous for distinguishing ice from dust. recent landing of MSL's rover Curiosity has provided The MastCam's left and right cameras can be used opportunities to extend the science return of the exist- simultaneously to image the sky, with a 440 nm blue ing instrument complement to include observations of filter on the right camera and a 750 nm red filter on the atmospheric water ice and dust. left. Alternately, sequential images taken in both wave- The participating science project “Observations of lengths with a single camera (typically MastCam Left), Water Ice and Winds from the MSL Rover” [1], in- can be used. The latter is the simplest case with which cluded proposed atmospheric measurements using sev- to begin as many camera-specific parameters will be eral MSL imagers. To date, several such data products identical for the pair of images.
    [Show full text]
  • Modeling the Development of Martian Sublimation Thermokarst Landforms
    Icarus 262 (2015) 154–169 Contents lists available at ScienceDirect Icarus journal homepage: www.journals.elsevier.com/icarus Modeling the development of martian sublimation thermokarst landforms a, b b Colin M. Dundas ⇑, Shane Byrne , Alfred S. McEwen a Astrogeology Science Center, U.S. Geological Survey, 2255 N. Gemini Dr., Flagstaff, AZ 86001, USA b Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA article info abstract Article history: Sublimation-thermokarst landforms result from collapse of the surface when ice is lost from the subsur- Received 8 August 2014 face. On Mars, scalloped landforms with scales of decameters to kilometers are observed in the mid- Revised 17 June 2015 latitudes and considered likely thermokarst features. We describe a landscape evolution model that cou- Accepted 29 July 2015 ples diffusive mass movement and subsurface ice loss due to sublimation. Over periods of tens of thou- Available online 21 August 2015 sands of Mars years under conditions similar to the present, the model produces scallop-like features similar to those on the martian surface, starting from much smaller initial disturbances. The model also Keywords: indicates crater expansion when impacts occur in surfaces underlain by excess ice to some depth, with Mars, surface morphologies similar to observed landforms on the martian northern plains. In order to produce these Geological processes Mars, climate landforms by sublimation, substantial quantities of excess ice are required, at least comparable to the vertical extent of the landform, and such ice must remain in adjacent terrain to support the non- deflated surface. We suggest that martian thermokarst features are consistent with formation by subli- mation, without melting, and that significant thicknesses of very clean excess ice (up to many tens of meters, the depth of some scalloped depressions) are locally present in the martian mid-latitudes.
    [Show full text]
  • Download the Acquired Data Or to Fix Possible Problem
    Università degli Studi di Napoli Federico II DOTTORATO DI RICERCA IN FISICA Ciclo 30° Coordinatore: Prof. Salvatore Capozziello Settore Scientifico Disciplinare FIS/05 Characterisation of dust events on Earth and Mars the ExoMars/DREAMS experiment and the field campaigns in the Sahara desert Dottorando Tutore Gabriele Franzese dr. Francesca Esposito Anni 2014/2018 A birbetta e giggione che sono andati troppo veloci e a patata che invece adesso va piano piano Summary Introduction ......................................................................................................................... 6 Chapter 1 Atmospheric dust on Earth and Mars............................................................ 9 1.1 Mineral Dust ....................................................................................................... 9 1.1.1 Impact on the Terrestrial land-atmosphere-ocean system .......................... 10 1.1.1.1 Direct effect ......................................................................................... 10 1.1.1.2 Semi-direct and indirect effects on the cloud physics ......................... 10 1.1.1.3 Indirect effects on the biogeochemical system .................................... 11 1.1.1.4 Estimation of the total effect ............................................................... 11 1.2 Mars .................................................................................................................. 12 1.2.1 Impact on the Martian land-atmosphere system ......................................... 13 1.3
    [Show full text]
  • Global Geometric Properties of Martian Impact Craters: a Preliminary Assessment Using Mars Orbiter Laser Altimeter (Mola)
    GLOBAL GEOMETRIC PROPERTIES OF MARTIAN IMPACT CRATERS: A PRELIMINARY ASSESSMENT USING MARS ORBITER LASER ALTIMETER (MOLA). J. B. Garvin1, S. E. H. Sakimoto2, C. Schnetzler3, and J. J. Frawley4, 1(NASAÕs GSFC, Code 921, Greenbelt, MD 20771 USA; [email protected]), 2(USRA at NASAÕs GSFC, Code 921, Greenbelt, MD 20771), 3(SSAI at NASAÕs GSFC) 4(H-STX and Herring Bay Geophysics at NASAÕs GSFC). Introduction: Impact craters on Mars have been ÒshapeÓ (n), central peak height, diameter D, volume, used to provide fundamental insights into the proper- shape, and many others. In this report, we treat the ties of the martian crust, the role of volatiles, the rela- crater depth versus diameter relationship, the crater rim tive age of the surface, and on the physics of impact height vs. diameter pattern, the statistics of ejecta cratering in the Solar System [1,2,6]. Before the three- thickness and its spatial distribution, and cavity geo- dimensional information provided by the Mars Orbiter metric properties, including interior deposit geometry. Laser Altimeter (MOLA) instrument which is currently Crater depth vs. Diameter: Using MOLA topog- operating in Mars orbit aboard the Mars Global Sur- raphic profile data, we have computed the total depth veyor (MGS), impact features were characterized mor- (from rim crest to lowest point on crater cavity floor) phologically using orbital images from Mariner 9 and and true depth (i.e., from pre-impact surface to mean Viking. Fresh-appearing craters were identified and crater floor level) for over 1300 craters. When we exam- measurements of their geometric properties were de- ine the correlation of depth d against diameter D, a rived from various image-based methods [3,6].
    [Show full text]
  • Impact Craters) Into the Subsurface
    SUBSURFACE MINERAL HETEROGENEITY IN THE MARTIAN CRUST AS SEEN BY THE THERMAL EMISSION IMAGING SYSTEM (THEMIS): VIEWS FROM NATURAL “WINDOWS” (IMPACT CRATERS) INTO THE SUBSURFACE. L. L. Tornabene1 , J. E. Moersch1, H. Y. McSween Jr.1, J. A. Piatek1 and P. R. Christensen2; 1Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, Tennessee 37996-1410, 2 Department of Geological Sciences, Arizona State University, Tempe, Arizona 85287–6305, USA. Introduction and Background: Impact craters have been effectively used as a “natural drill” into the crust of the moon, the Earth and on Mars, giving us a glimpse of the mineral and lithologic compositions that are otherwise not exposed or present on surfaces. A lunar study by Tomp- kins and Pieters [1] has demonstrated that Lunar Clementine data could be used to show that numerous craters on the Moon excavated distinct compositions within both the cen- tral uplift and craters walls/terraces of several complex cra- ters with respect to the surrounding lunar surface composi- tion. Later, Tornabene et al [2] demonstrated how Haughton impact structure was an excellent terrestrial analog for dem- onstrating the utility of using craters for studying both near- subsurface and the shallow crust of Mars. Using ASTER Thermal infrared (TIR) data, as an analog for THEMIS TIR, three subsurface units were distinguished within the structure as units that were excavated and uplifted by the impact event. These units, if not for the regional tilt and erosion, would otherwise not be presently exposed if not for the Haughton event. Meanwhile, recent studies on Mars by the Opportunity rover [3] revealed our first clear view of out- cropping bedrock of sedimentary layers within the walls of Eagle and Endurance craters.
    [Show full text]
  • Dust Devil Track Survey at the Insight Landing Sites: Implications for the Probability of Solar Panel Clearing Events
    46th Lunar and Planetary Science Conference (2015) 2070.pdf DUST DEVIL TRACK SURVEY AT THE INSIGHT LANDING SITES: IMPLICATIONS FOR THE PROBABILITY OF SOLAR PANEL CLEARING EVENTS. D. Reiss1 and R. D. Lorenz2, Institut für Planeto- logie, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany, 2Johns Hopkins Uni- versity Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA. Introduction: The InSight robotic lander is scheduled Morphology. Fig. 2 shows an example of a typical newly to land on Mars in September 2016. InSight was designed to formed DDT. The DDTs in the study region are relatively perform the first comprehensive surface-based geophysical straight which is also expressed in their low mean sinuosity investigation of Mars [1]. Passage of vortices may have a of 1.03 (standard deviation = 0.004). The sinuosity is lower number of influences on the geophysical measurements to be compared to mean values of ~1.3 and ~1.08 measured by [8] made by InSight. Seismic data could be influenced by dust in Russell and Gusev crater, respectively. devils and vortices via several mechanisms such as loading of the elastic ground by a surface pressure field which causes a local tilt [e.g. 2]. In addition, the power supply of the In- Sight instruments is provided by solar arrays. Solar-powered missions on Mars like the Sojourner rover in 1997 were af- fected by a decline in electrical power output by 0.2-0.3 % per day caused by steadily dust deposition on its horizontal Fig. 2. Example of observed track formation between HiRISE imag- solar panel [3].
    [Show full text]
  • Scalloped Terrains in the Peneus and Amphitrites Paterae Region of Mars As Observed by Hirise
    Icarus 205 (2010) 259–268 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Scalloped terrains in the Peneus and Amphitrites Paterae region of Mars as observed by HiRISE A. Lefort *, P.S. Russell, N. Thomas Space Research and Planetary Sciences, Physikalisches Institut, Universität Bern, 3012 Bern, Switzerland article info abstract Article history: The Peneus and Amphitrites Paterae region of Mars displays large areas of smooth, geologically young Received 10 October 2008 terrains overlying a rougher and older topography. These terrains may be remnants of the mid-latitude Revised 15 May 2009 mantle deposit, which is thought to be composed of ice-rich material originating from airfall deposition Accepted 3 June 2009 during a high-obliquity period less than 5 Ma ago. Within these terrains, there are several types of poten- Available online 14 June 2009 tially periglacial features. In particular, there are networks of polygonal cracks and scalloped-shaped depressions, which are similar to features found in Utopia Planitia in the northern hemisphere. This area Keywords: also displays knobby terrain similar to the so-called ‘‘basketball terrains” of the mid and high martian lat- Mars, Surface itudes. We use recent high resolution images from the High Resolution Imaging Science Experiment (HiR- Geological processes Ices ISE) along with data from previous Mars missions to study the small-scale morphology of the scalloped terrains, and associated polygon network and knobby terrains. We compare these with the features observed in Utopia Planitia and attempt to determine their formation process. While the two sites share many general features, scallops in Peneus/Amphitrites Paterae lack the diverse polygon network (i.e.
    [Show full text]