DOCSLIB.ORG

The Last Two Meters of Exhumation at Mount Sharp: Linking Rover-Scale Geomorphology, Taphonomy, and Winds

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Last Two Meters of Exhumation at Mount Sharp: Linking Rover-Scale Geomorphology, Taphonomy, and Winds The Last Two Meters of Exhumation at Mount Sharp: Linking Rover-scale Geomorphology, Taphonomy, and Winds For submission to ROSES – MSL Participating Scientist Program 2015 (NNH15ZDA001N-MSLPSP) 1. Table of contents. ..................................................................................................................... 0 2. Scientific/Technical/Management. ......................................................................................... 1 2.1. Summary, Objectives, and Expected Significance. ........................................................ 1 2.2 Scientific Background. ....................................................................................................... 1 2.2.1. Exhumation processes link Mount Sharp geomorphology and climate ....................... 1 2.2.2. Taphonomy can be constrained by rover investigation of exhumation processes ....... 4 2.2.3. Winds’ role in exhumation can be constrained by rover investigation. ........................ 5 2.3 Technical Approach and Methodology. ........................................................................... 6 2.3.1. Stereo-Enabled Slope Analysis of Exhumation Susceptibility. ................................... 7 2.3.2. Mapping Aeolian-Exhumation Potential with Mastcam, REMS, and Modeling ......... 9 2.3.3. Assessing the Role of Late-Stage Weathering in Mount Sharp’s Exhumation ........... 11 2.3.4. Quantifying Exhumation’s Impact on Organic Matter Preservation Potential ........... 12 2.3.5. Assumptions and Caveats ............................................................................................ 14 2.4. Perceived Impact of the Proposed Work ......................................................................... 14 2.5. Relevance of Proposed Work to NASA Goals, MSL Goals, and MSL Mission-level Science Objectives. ........................................................................... 14 2.6. Work Plan. ........................................................................................................................ 15 2.7. Personnel and Qualifications. ........................................................................................... 15 3. References. ............................................................................................................................. 16 4. Biographical Sketch. .............................................................................................................. 28 5. Summary of Work Effort. .................................................................................................... 30 6. Current and Pending Support. ............................................................................................. 31 7. Statements of Commitment and Support. ........................................................................... 32 8. Budget Justification. .............................................................................................................. 34 8.1. Budget Narrative. ........................................................................................................... 34 8.1.1. Budget Analysis to Ensure That Participation in Daily Operations is Sufficiently Supported. ............................................................................................... 34 8.1.2. Facilities and Equipment. ............................................................................................. 37 8.2 Budget Details. ................................................................................................................... 38 9. Data Management Plan. ....................................................................................................... 41 The last two meters of exhumation at Mount Sharp: Linking rover-scale geomorphology, taphonomy, and winds 2. Scientific/Technical/Management: 2.1. Summary, Objectives, and Expected Significance. In what locations along MSL’s planned traverse have Mount Sharp’s rocks been exhumed over the last 106-109 years sufficiently rapidly to preserve complex organic matter? How has this exhumation been affected by microclimates, and differential rock resistance? To what extent have wind stress, abrader availability, and rare wetting events, controlled the pattern of exhumation? Motivated by the importance of exhumation as a control on taphonomy and as a proxy for climate-driven change, the broad objectives of this proposal are to analyze relief along the planned MSL traverse as a proxy for exhumation processes, determine the pattern of saltation-abrasion potential, and constrain the role of physical abrasion and aqueous processes in exhuming the rocks of Mount Sharp (Aeolis Mons). We will address these objectives through Mastcam, MAHLI and REMS measurements (of topography, rock texture, and winds), supported by modeling, with secondary contributions from DAN. The investigation requires participation in the science team to acquire specific measurements. Specifically, we will use Mastcam [Malin et al. 2010] and MAHLI [Edgett et al. 2012] images, and simple numerical models, to constrain landform degradation and erosional resistance. In parallel, we will use Mastcam image data, models, and REMS [Gómez-Elvira et al. 2012] observations, to carry out landform-scale mapping of saltation-abrasion potential. We will also use Mastcam, REMS, and the PI’s snowmelt model [Kite et al., 2013b], to quantify the possible role of aqueous fluids in exhumation. We shall thus obtain an improved understanding of the exhumation of sedimentary rocks at the <2m length scale and 106-109 yr timescale that are relevant to the preservation of complex organic matter and to geologically recent climate change. Locations with >2 m of geologically recent (<<109 yr) exhumation have improved potential to preserve complex organic matter [Farley et al. 2014, Grotzinger et al. 2014]. Given the importance of taphonomy to mission goals [MSL Extended Mission Plan 2014], improved understanding of exhumation – and identifying correlates of recent exhumation remotely and on an operational timescale – can enhance the science return from MSL. The proposed research will improve the science team’s ability to understand controls on recent exhumation by integrating data from multiple instruments and promptly comparing them to models. This can enhance the science return from SAM cosmogenic age-dating, by enabling predictions further along the traverse, and for future landing sites. The proposal builds on >8 years of experience by the PI with Mars microclimates, Mars erosion, and late-stage aqueous processes on Mars, and will leverage the PI’s existing funded project to study mountain-terrain effects on exhumation using the Mars meteorological model MRAMS (the PI has previously published papers using MRAMS; Kite et al. 2011a, 2011b) as well as the PI’s published models of Mount Sharp wind erosion and late-stage snowmelt at Mount Sharp [Kite et al. 2013b, 2013c]. Equally important to our proposed scientific investigation is our contribution to the success of the rover’s day-to-day operations, by providing scientists (the PI, a postdoc, and a graduate student) to serve in daily operational roles and assist in the acquisition of specific measurements. 2.2. Scientific Background. 2.2.1. Exhumation processes link Mount Sharp geomorphology and climate. Exhumation is necessary to form the moat that defines Mount Sharp, and to expose the mountain’s outcropping layers. Ongoing exhumation is suggested by Mount Sharp’s low crater density (Fig. 1) [Thomson et al. 2011]. Exhumation requires comminution of rock to fragments, 1 The last two meters of exhumation at Mount Sharp: Linking rover-scale geomorphology, taphonomy, and winds Extended Mission Exhumation Rates are Exhumation-Rate Variability Predicted to be Strongly Variable Matters for Taphonomy Crater Diameter (km) -2 -1 Organic Matter Surviving Radiolysis 10 10 100% 50% 0% 50% 100% 10-6 10-6 Ascent Canyons Mesa Tops Fan-Shaped Feature 500 amu Fractured Unit+Hummocky Plains Steady Exhumation 200 amu 10-7 EXTENDED MISSION(S) 10-7 113 EXTENDED amu MISSION(S) -8 113 amu: 0.01% -8 10 -17 10 500 amu: 10 % Crater-Obliteration Rate (m/yr) Single Resurfacing PRIMARY PRIMARY MISSION Kminek & Bada (2006) MISSION Equivalent Steady Exhumation Rate (m/yr) Dartnell et al. (2007) Hartmann (2005) crater !uxes. GCR only. Truncated at 0.13 km crater diameter. Farley et al. (2014) SCR neglected. Consistent with Sefton-Nash et al. (2014) adjusted to equivalent 500 amu values (dashed) and Newsom et al. (2015). steady exhumation. are extrapolated. 10-9 10-9 Fig. 1. Exhumation variability has significant implications for the preservation of complex organic matter. MSL’s Extended Mission will encounter terrains with higher crater-obliteration rates than terrain encountered during the Primary Mission. Crater-obliteration curves on Mt. Sharp are consistent with steady exhumation [Smith et al. 2008]. If steady exhumation is occurring (testable with Mastcam; §2.3.1) then enhanced organic-matter preservation potential is expected at Mount Sharp. For details, see §2.2.2 and §2.3.4. Phyllosilicates are mapped at the stratigraphic level of rapid crater obliteration [Thomson et al. 2011]. and surface shear stresses (wind or water) sufficient to export rock fragments from the mountain.1 Landscape-modification rates and processes can be interpreted using crater size- frequency distributions (CSFDs) (Fig. 1). CSFDs for Gale’s moat are well-explained by rare pulses of resurfacing [Newsom et al. 2015], in agreement
Load more

Recommended publications
  • Meteorites on Mars Observed with the Mars Exploration Rovers C
    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 113, E06S22, doi:10.1029/2007JE002990, 2008 Meteorites on Mars observed with the Mars Exploration Rovers C. Schro¨der,1 D. S. Rodionov,2,3 T. J. McCoy,4 B. L. Jolliff,5 R. Gellert,6 L. R. Nittler,7 W. H. Farrand,8 J. R. Johnson,9 S. W. Ruff,10 J. W. Ashley,10 D. W. Mittlefehldt,1 K. E. Herkenhoff,9 I. Fleischer,2 A. F. C. Haldemann,11 G. Klingelho¨fer,2 D. W. Ming,1 R. V. Morris,1 P. A. de Souza Jr.,12 S. W. Squyres,13 C. Weitz,14 A. S. Yen,15 J. Zipfel,16 and T. Economou17 Received 14 August 2007; revised 9 November 2007; accepted 21 December 2007; published 18 April 2008. [1] Reduced weathering rates due to the lack of liquid water and significantly greater typical surface ages should result in a higher density of meteorites on the surface of Mars compared to Earth. Several meteorites were identified among the rocks investigated during Opportunity’s traverse across the sandy Meridiani plains. Heat Shield Rock is a IAB iron meteorite and has been officially recognized as ‘‘Meridiani Planum.’’ Barberton is olivine-rich and contains metallic Fe in the form of kamacite, suggesting a meteoritic origin. It is chemically most consistent with a mesosiderite silicate clast. Santa Catarina is a brecciated rock with a chemical and mineralogical composition similar to Barberton. Barberton, Santa Catarina, and cobbles adjacent to Santa Catarina may be part of a strewn field. Spirit observed two probable iron meteorites from its Winter Haven location in the Columbia Hills in Gusev Crater.
    [Show full text]
  • Owner's Manual,1996 Pontiac Bonneville
    I LLt -The 1996 Pontiac Bonneville Owner’s Manual Seats and Restraint Systems ............................................................. 1-1 This section tells you how to use your seats and safety belts properly. It also explains“SRS” the system. Features and Controls ..................... ;............................................ 2-1 This section explainshow to start and operate your Pontiac. Comfort Controls and Audio Systems ...................................................... 3-1 This section tells you how to adjust the ventilation and comfort controls andhow to operate your audio system. Your Driving and the Road .............................................................. 4-1 Here you’ll find helpful information and tips about the roadhow and to drive under different conditions. ProblemsontheRoad .................................................................. 5-1 This section tells you whatto do if you have a problem whiledriving, such as a flat tire or overheated engine, etc. Service and Appearance Care.. .......................................................... 6-1 Here the manual tellsyou how to keep your Pontiacrunning properly and looking good. Maintenanceschedule......... .......................................................... 7-1 This section tellp you when to perform vehicle maintenance and what fluidsand lubricants to use. Customer Assistance Information ... .#.................................................... 8-1 \ This section tells youhow to contact Pontiac for assistance and how to get service and
    [Show full text]
  • Widespread Crater-Related Pitted Materials on Mars: Further Evidence for the Role of Target Volatiles During the Impact Process ⇑ Livio L
    Icarus 220 (2012) 348–368 Contents lists available at SciVerse ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Widespread crater-related pitted materials on Mars: Further evidence for the role of target volatiles during the impact process ⇑ Livio L. Tornabene a, , Gordon R. Osinski a, Alfred S. McEwen b, Joseph M. Boyce c, Veronica J. Bray b, Christy M. Caudill b, John A. Grant d, Christopher W. Hamilton e, Sarah Mattson b, Peter J. Mouginis-Mark c a University of Western Ontario, Centre for Planetary Science and Exploration, Earth Sciences, London, ON, Canada N6A 5B7 b University of Arizona, Lunar and Planetary Lab, Tucson, AZ 85721-0092, USA c University of Hawai’i, Hawai’i Institute of Geophysics and Planetology, Ma¯noa, HI 96822, USA d Smithsonian Institution, Center for Earth and Planetary Studies, Washington, DC 20013-7012, USA e NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA article info abstract Article history: Recently acquired high-resolution images of martian impact craters provide further evidence for the Received 28 August 2011 interaction between subsurface volatiles and the impact cratering process. A densely pitted crater-related Revised 29 April 2012 unit has been identified in images of 204 craters from the Mars Reconnaissance Orbiter. This sample of Accepted 9 May 2012 craters are nearly equally distributed between the two hemispheres, spanning from 53°Sto62°N latitude. Available online 24 May 2012 They range in diameter from 1 to 150 km, and are found at elevations between À5.5 to +5.2 km relative to the martian datum. The pits are polygonal to quasi-circular depressions that often occur in dense clus- Keywords: ters and range in size from 10 m to as large as 3 km.
    [Show full text]
  • Geologic Map of the Twin Falls 30 X 60 Minute Quadrangle, Idaho
    Geologic Map of the Twin Falls 30 x 60 Minute Quadrangle, Idaho Compiled and Mapped by Kurt L. Othberg, John D. Kauffman, Virginia S. Gillerman, and Dean L. Garwood 2012 Idaho Geological Survey Third Floor, Morrill Hall University of Idaho Geologic Map 49 Moscow, Idaho 83843-3014 2012 Geologic Map of the Twin Falls 30 x 60 Minute Quadrangle, Idaho Compiled and Mapped by Kurt L. Othberg, John D. Kauffman, Virginia S. Gillerman, and Dean L. Garwood INTRODUCTION 43˚ 115˚ The geology in the 1:100,000-scale Twin Falls 30 x 23 13 18 7 8 25 60 minute quadrangle is based on field work conduct- ed by the authors from 2002 through 2005, previous 24 17 14 16 19 20 26 1:24,000-scale maps published by the Idaho Geological Survey, mapping by other researchers, and compilation 11 10 from previous work. Mapping sources are identified 9 15 12 6 in Figures 1 and 2. The geologic mapping was funded in part by the STATEMAP and EDMAP components 5 1 2 22 21 of the U.S. Geological Survey’s National Cooperative 4 3 42˚ 30' Geologic Mapping Program (Figure 1). We recognize 114˚ that small map units in the Snake River Canyon are dif- 1. Bonnichsen and Godchaux, 1995a 15. Kauffman and Othberg, 2005a ficult to identify at this map scale and we direct readers 2. Bonnichsen and Godchaux, 16. Kauffman and Othberg, 2005b to the 1:24,000-scale geologic maps shown in Figure 1. 1995b; Othberg and others, 2005 17. Kauffman and others, 2005a 3.
    [Show full text]
  • Mars Science Laboratory: Curiosity Rover Curiosity’S Mission: Was Mars Ever Habitable? Acquires Rock, Soil, and Air Samples for Onboard Analysis
    National Aeronautics and Space Administration Mars Science Laboratory: Curiosity Rover www.nasa.gov Curiosity’s Mission: Was Mars Ever Habitable? acquires rock, soil, and air samples for onboard analysis. Quick Facts Curiosity is about the size of a small car and about as Part of NASA’s Mars Science Laboratory mission, Launch — Nov. 26, 2011 from Cape Canaveral, tall as a basketball player. Its large size allows the rover Curiosity is the largest and most capable rover ever Florida, on an Atlas V-541 to carry an advanced kit of 10 science instruments. sent to Mars. Curiosity’s mission is to answer the Arrival — Aug. 6, 2012 (UTC) Among Curiosity’s tools are 17 cameras, a laser to question: did Mars ever have the right environmental Prime Mission — One Mars year, or about 687 Earth zap rocks, and a drill to collect rock samples. These all conditions to support small life forms called microbes? days (~98 weeks) help in the hunt for special rocks that formed in water Taking the next steps to understand Mars as a possible and/or have signs of organics. The rover also has Main Objectives place for life, Curiosity builds on an earlier “follow the three communications antennas. • Search for organics and determine if this area of Mars was water” strategy that guided Mars missions in NASA’s ever habitable for microbial life Mars Exploration Program. Besides looking for signs of • Characterize the chemical and mineral composition of Ultra-High-Frequency wet climate conditions and for rocks and minerals that ChemCam Antenna rocks and soil formed in water, Curiosity also seeks signs of carbon- Mastcam MMRTG • Study the role of water and changes in the Martian climate over time based molecules called organics.
    [Show full text]
  • Exhumation of a Collisional Orogen: a Perspective from the North American Grenville Province
    Geological Society of America Memoir 197 2004 Exhumation of a collisional orogen: A perspective from the North American Grenville Province Margaret M. Streepey* Department of Geological Sciences, Florida State University, Tallahassee, Florida 32306-4100, USA Carolina Lithgow-Bertelloni Ben A. van der Pluijm Eric J. Essene Department of Geological Science, University of Michigan, Ann Arbor, Michigan 48109-1063, USA Jerry F. Magloughlin Department of Earth Resources, Colorado State University, Fort Collins, Colorado 80523-1482, USA ABSTRACT Combined structural and geochronologic research in the southernmost portion of the contiguous Grenville Province of North America (Ontario and New York State) show protracted periods of extension after the last episode of contraction. The Grenville Province in this area is characterized by synorogenic extension at ca. 1040 Ma, supported by U-Pb data on titanites and 40Ar-39Ar data on hornblendes, followed by regional extension occurring along crustal-scale shear zones between 945 and 780 Ma, as recorded by 40Ar-39Ar analysis of hornblende, biotite, and K-feldspar. By ca. 780 Ma the southern portion of the Grenville Province, from Ontario to the Adiron- dack Highlands, underwent uplift as a uniform block. Tectonic hypotheses have invoked various driving mechanisms to explain the transition from compression to extension; however, such explanations are thus far geodynamically unconstrained. Numerical models indicate that mechanisms such as gravitational collapse and man- tle delamination act over timescales that cannot explain a protracted 300 m.y. exten- sional history that is contemporaneous with ongoing uplift of the Grenville Province. Rather, the presence of a plume upwelling underneath the Laurentian margin, com- bined with changes in regional stress directions, permitted the observed uplift and extension in the Grenville Province during this time.
    [Show full text]
  • Exhumation Processes
    Exhumation processes UWE RING1, MARK T. BRANDON2, SEAN D. WILLETT3 & GORDON S. LISTER4 1Institut fur Geowissenschaften,Johannes Gutenberg-Universitiit,55099 Mainz, Germany 2Department of Geology and Geophysics, Yale University, New Haven, CT 06520, USA 3Department of Geosciences, Pennsylvania State University, University Park, PA I 6802, USA Present address: Department of Geological Sciences, University of Washington, Seattle, WA 98125, USA 4Department of Earth Sciences, Monash University, Clayton, Victoria VIC 3168,Australia Abstract: Deep-seated metamorphic rocks are commonly found in the interior of many divergent and convergent orogens. Plate tectonics can account for high-pressure meta­ morphism by subduction and crustal thickening, but the return of these metamorphosed crustal rocks back to the surface is a more complicated problem. In particular, we seek to know how various processes, such as normal faulting, ductile thinning, and erosion, con­ tribute to the exhumation of metamorphic rocks, and what evidence can be used to distin­ guish between these different exhumation processes. In this paper, we provide a selective overview of the issues associated with the exhuma­ tion problem. We start with a discussion of the terms exhumation, denudation and erosion, and follow with a summary of relevant tectonic parameters. Then, we review the charac­ teristics of exhumation in differenttectonic settings. For instance, continental rifts, such as the severely extended Basin-and-Range province, appear to exhume only middle and upper crustal rocks, whereas continental collision zones expose rocks from 125 km and greater. Mantle rocks are locally exhumed in oceanic rifts and transform zones, probably due to the relatively thin crust associated with oceanic lithosphere.
    [Show full text]
  • EGU2015-6247, 2015 EGU General Assembly 2015 © Author(S) 2015
    Geophysical Research Abstracts Vol. 17, EGU2015-6247, 2015 EGU General Assembly 2015 © Author(s) 2015. CC Attribution 3.0 License. From Kimberley to Pahrump_Hills: toward a working sedimentary model for Curiosity’s exploration of strata from Aeolis Palus to lower Mount Sharp in Gale crater Sanjeev Gupta (1), David Rubin (2), Katie Stack (3), John Grotzinger (4), Rebecca Williams (5), Lauren Edgar (6), Dawn Sumner (7), Melissa Rice (8), Kevin Lewis (9), Michelle Minitti (5), Juergen Schieber (10), Ken Edgett (11), Ashwin Vasawada (3), Marie McBride (11), Mike Malin (11), and the MSL Science Team (1) Imperial College London, London, United Kingdom ([email protected]), (2) UC, Santa Cruz, CA, USA, (3) Jet Propulsion Laboratory, Pasadena, CA, USA, (4) California Institute of Technology, Pasadena, CA, USA, (5) Planetary Science INstitute, Tucson, AZ, USA, (6) USGS, Flagstaff, AZ, USA, (7) UC, Davis, CA, USA, (8) Western Washington University, Bellingham, WA, USA, (9) Johns Hopkins University, Baltimore, Maryland, USA, (10) Indiana University, Bloomington, Indiana, USA, (11) Malin Space Science Systems, San Diego, CA, USA In September 2014, NASA’s Curiosity rover crossed the transition from sedimentary rocks of Aeolis Palus to those interpreted to be basal sedimentary rocks of lower Aeolis Mons (Mount Sharp) at the Pahrump Hills outcrop. This transition records a change from strata dominated by coarse clastic deposits comprising sandstones and conglomerate facies to a succession at Pahrump Hills that is dominantly fine-grained mudstones and siltstones with interstratified sandstone beds. Here we explore the sedimentary characteristics of the deposits, develop depositional models in the light of observed physical characteristics and develop a working stratigraphic model to explain stratal relationships.
    [Show full text]
  • March 21–25, 2016
    FORTY-SEVENTH LUNAR AND PLANETARY SCIENCE CONFERENCE PROGRAM OF TECHNICAL SESSIONS MARCH 21–25, 2016 The Woodlands Waterway Marriott Hotel and Convention Center The Woodlands, Texas INSTITUTIONAL SUPPORT Universities Space Research Association Lunar and Planetary Institute National Aeronautics and Space Administration CONFERENCE CO-CHAIRS Stephen Mackwell, Lunar and Planetary Institute Eileen Stansbery, NASA Johnson Space Center PROGRAM COMMITTEE CHAIRS David Draper, NASA Johnson Space Center Walter Kiefer, Lunar and Planetary Institute PROGRAM COMMITTEE P. Doug Archer, NASA Johnson Space Center Nicolas LeCorvec, Lunar and Planetary Institute Katherine Bermingham, University of Maryland Yo Matsubara, Smithsonian Institute Janice Bishop, SETI and NASA Ames Research Center Francis McCubbin, NASA Johnson Space Center Jeremy Boyce, University of California, Los Angeles Andrew Needham, Carnegie Institution of Washington Lisa Danielson, NASA Johnson Space Center Lan-Anh Nguyen, NASA Johnson Space Center Deepak Dhingra, University of Idaho Paul Niles, NASA Johnson Space Center Stephen Elardo, Carnegie Institution of Washington Dorothy Oehler, NASA Johnson Space Center Marc Fries, NASA Johnson Space Center D. Alex Patthoff, Jet Propulsion Laboratory Cyrena Goodrich, Lunar and Planetary Institute Elizabeth Rampe, Aerodyne Industries, Jacobs JETS at John Gruener, NASA Johnson Space Center NASA Johnson Space Center Justin Hagerty, U.S. Geological Survey Carol Raymond, Jet Propulsion Laboratory Lindsay Hays, Jet Propulsion Laboratory Paul Schenk,
    [Show full text]
  • Regional Investigations of the Effects of Secondaries Upon the Martian Cratering Record
    46th Lunar and Planetary Science Conference (2015) 2630.pdf REGIONAL INVESTIGATIONS OF THE EFFECTS OF SECONDARIES UPON THE MARTIAN CRATERING RECORD. Asmin V. Pathare1 and Jean-Pierre Williams2 1Planetary Science Institute, Tucson, AZ 85719 ([email protected]) 2Earth, Planetary, and Space Sciences, University of California , Los Angeles, CA 90095. Motivation: We consider the following paradox: if Zunil-type impacts can generate tens of millions of secondary craters on Mars approximately once every million years [1], then why do so many martian crater counts show so little isochronal evidence (e.g., [2]) of secondary “contamination”? We suggest three possible explanations for this incongruity: (1) Atmospheric Pressure Variations: lower pres- sures at low obliquities may have facilitated massive secondary generation at the time of the Zunil impact; alternatively, higher pressures at high obliquities may have inhibited secondary cratering from other Zunil- sized impacts. (2) Target Material Strength: Zunil impacting into a notably weak regolith may have augmented second- ary crater production relative to similar-sized craters. (3) Surface Modification: secondary craters from previous Zunil-sized impacts may have once been just as prominent as those emanating from Zunil, but have since been obliterated by rapid resurfacing over the past 100 Myr. Figure 1. Modeled annual SFDs for the locations of As part of a newly-funded MDAP, we will conduct Zunil and Pangboche craters and isochrons derived regional investigations of secondary cratering to help from polynomial fits. The crater counts from the two locations are scaled to the same time/area for compari- distinguish amongst these three potential explanations. son with the annual isochrons.
    [Show full text]
  • A Two-Step K-Ar Experiment on Mars: Dating the Diagenetic 10.1002/2017JE005445 Formation of Jarosite from Amazonian Groundwaters Key Points: P
    PUBLICATIONS Journal of Geophysical Research: Planets RESEARCH ARTICLE A Two-Step K-Ar Experiment on Mars: Dating the Diagenetic 10.1002/2017JE005445 Formation of Jarosite from Amazonian Groundwaters Key Points: P. E. Martin1 , K. A. Farley1, M. B. Baker1, C. A. Malespin2, S. P. Schwenzer3 , B. A. Cohen2, • A third radiometric age dating 2 2 4 5 6 experiment has been conducted on P. R. Mahaffy , A. C. McAdam , D. W. Ming , P. M. Vasconcelos , and R. Navarro-González Mars 1 2 • The model formation age of Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA, NASA Goddard 3 4 plagioclase is greater than 4 Ga, while Space Flight Center, Greenbelt, MD, USA, Department of Physical Sciences, Open University, Milton Keynes, UK, NASA the model age for jarosite is less than Johnson Space Center, Houston, TX, USA, 5School of Earth Sciences, University of Queensland, Brisbane, Queensland, 3Ga Australia, 6Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City, • The young jarosite age suggests the presence of liquid water in Gale Crater Mexico during the Amazonian period, most likely in the subsurface Abstract Following K-Ar dating of a mudstone and a sandstone, a third sample has been dated by the Curiosity rover exploring Gale Crater. The Mojave 2 mudstone, which contains relatively abundant jarosite, Supporting Information: σ • Supporting Information S1 yielded a young K-Ar bulk age of 2.57 ± 0.39 Ga (1 precision). A two-step heating experiment was implemented in an effort to resolve the K-Ar ages of primary and secondary mineralogical components Correspondence to: within the sample.
    [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]