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Zhang N, Zhang Y. Correlation between gyral size, brain size, and head impact risk across mammalian species. Brain Res 2024; 1828:148768. [PMID: 38244756 DOI: 10.1016/j.brainres.2024.148768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/12/2023] [Accepted: 01/12/2024] [Indexed: 01/22/2024]
Abstract
A study on primates has established that gyral size is largely independent of overall brain size. Building on this-and other research suggesting that brain gyrification may mitigate the effects of head impacts-our study aims to explore potential correlations between gyral size and the risk of head impact across a diverse range of mammalian species. Our findings corroborate the idea that gyral sizes are largely independent of brain sizes, especially among species with larger brains, thus extending this observation beyond primates. Preliminary evidence also suggests a correlation between an animal's gyral size and its lifestyle, particularly in terms of head-impact risk. For instance, goats, known for their headbutting behaviors, exhibit smaller gyral sizes. In contrast, species such as manatees and dugongs, which typically face lower risks of head impact, have lissencephalic brains. Additionally, we explore mechanisms that may explain how narrower gyral sizes could offer protective advantages against head impact. Finally, we discuss a possible trade-off associated with gyrencephaly.
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Affiliation(s)
- Nianqin Zhang
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - Yongjun Zhang
- Science College, Liaoning Technical University, Fuxin 123000, China.
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Wakita S, Johnson BC, Garrick-Bethell I, Kelley MR, Maxwell RE, Davison TM. Impactor material records the ancient lunar magnetic field in antipodal anomalies. Nat Commun 2021; 12:6543. [PMID: 34764304 PMCID: PMC8586259 DOI: 10.1038/s41467-021-26860-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 10/27/2021] [Indexed: 11/10/2022] Open
Abstract
The Moon presently has no dynamo, but magnetic fields have been detected over numerous portions of its crust. Most of these regions are located antipodal to large basins, leading to the hypothesis that lunar rock ejected during basin-forming impacts accumulated at the basin antipode and recorded the ambient magnetic field. However, a major problem with this hypothesis is that lunar materials have low iron content and cannot become strongly magnetized. Here we simulate oblique impacts of 100-km-diameter impactors at high resolution and show that an ~700 m thick deposit of potentially iron-rich impactor material accumulates at the basin antipode. The material is shock-heated above the Curie temperature and therefore may efficiently record the ambient magnetic field after deposition. These results explain a substantial fraction of the Moon's crustal magnetism, and are consistent with a dynamo field strength of at least several tens of microtesla during the basin-forming epoch.
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Affiliation(s)
- S Wakita
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, 47907, USA.
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - B C Johnson
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, 47907, USA
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - I Garrick-Bethell
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA, 05064, USA
- School of Space Research, Kyung Hee University, Yongin, Gyeonggi, 446-701, Korea
| | - M R Kelley
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA, 05064, USA
| | - R E Maxwell
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA, 05064, USA
| | - T M Davison
- Department of Earth Science and Engineering, Imperial College London, London, SW7 2AZ, UK
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New discovery of two seismite horizons challenges the Ries-Steinheim double-impact theory. Sci Rep 2020; 10:22143. [PMID: 33335157 PMCID: PMC7747748 DOI: 10.1038/s41598-020-79032-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/30/2020] [Indexed: 11/08/2022] Open
Abstract
The Nördlinger Ries and the Steinheim Basin are widely perceived as a Middle Miocene impact crater doublet. We discovered two independent earthquake-produced seismite horizons in North Alpine Foreland Basin deposits potentially related to both impacts. The older seismite horizon, demonstrated to be associated with the Ries impact, is overlain by distal impact ejecta in situ, forming a unique continental seismite-ejecta couplet within a distance of up to 180 km from the crater. The younger seismite unit, also produced by a major palaeo-earthquake, comprises clastic dikes that cut through the Ries seismite-ejecta couplet. The clastic dikes may have formed in response to the Steinheim impact, some kyr after the Ries impact, in line with paleontologic results that indicate a time gap of about 0.5 Myr between the Ries and Steinheim events. This interpretation suggests the Ries and Steinheim impacts represent two temporally separate events in Southern Germany that, thus, witnessed a double disaster in the Middle Miocene. The magnitude–distance relationship of seismite formation during large earthquakes suggests the seismic and destructive potential of impact-induced earthquakes may be underestimated.
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Rodriguez JAP, Leonard GJ, Kargel JS, Domingue D, Berman DC, Banks M, Zarroca M, Linares R, Marchi S, Baker VR, Webster KD, Sykes M. The Chaotic Terrains of Mercury Reveal a History of Planetary Volatile Retention and Loss in the Innermost Solar System. Sci Rep 2020; 10:4737. [PMID: 32179758 PMCID: PMC7075900 DOI: 10.1038/s41598-020-59885-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 01/24/2020] [Indexed: 11/25/2022] Open
Abstract
Mercury’s images obtained by the 1974 Mariner 10 flybys show extensive cratered landscapes degraded into vast knob fields, known as chaotic terrain (AKA hilly and lineated terrain). For nearly half a century, it was considered that these terrains formed due to catastrophic quakes and ejecta fallout produced by the antipodal Caloris basin impact. Here, we present the terrains’ first geologic examination based on higher spatial resolution MESSENGER (MErcury Surface Space ENvironment GEochemistry and Ranging) imagery and laser altimeter topography. Our surface age determinations indicate that their development persisted until ~1.8 Ga, or ~2 Gyrs after the Caloris basin formed. Furthermore, we identified multiple chaotic terrains with no antipodal impact basins; hence a new geological explanation is needed. Our examination of the Caloris basin’s antipodal chaotic terrain reveals multi-kilometer surface elevation losses and widespread landform retention, indicating an origin due to major, gradual collapse of a volatile-rich layer. Crater interior plains, possibly lavas, share the chaotic terrains’ age, suggesting a development associated with a geothermal disturbance above intrusive magma bodies, which best explains their regionality and the enormity of the apparent volume losses involved in their development. Furthermore, evidence of localized, surficial collapse, might reflect a complementary, and perhaps longer lasting, devolatilization history by solar heating.
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Affiliation(s)
- J Alexis P Rodriguez
- Planetary Science Institute, 1700 E Fort Lowell Road, Suite 106, Tucson, AZ, USA.
| | - Gregory J Leonard
- Department of Planetary Sciences, University of Arizona, Tucson, AZ, USA
| | - Jeffrey S Kargel
- Planetary Science Institute, 1700 E Fort Lowell Road, Suite 106, Tucson, AZ, USA
| | - Deborah Domingue
- Planetary Science Institute, 1700 E Fort Lowell Road, Suite 106, Tucson, AZ, USA
| | - Daniel C Berman
- Planetary Science Institute, 1700 E Fort Lowell Road, Suite 106, Tucson, AZ, USA
| | - Maria Banks
- Planetary Science Institute, 1700 E Fort Lowell Road, Suite 106, Tucson, AZ, USA.,NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Mario Zarroca
- External Geodynamics and Hydrogeology Group, Department of Geology, Autonomous University of Barcelona, 08193, Bellaterra, Barcelona, Spain
| | - Rogelio Linares
- External Geodynamics and Hydrogeology Group, Department of Geology, Autonomous University of Barcelona, 08193, Bellaterra, Barcelona, Spain
| | - Simone Marchi
- Southwest Research Institute, 1050 Walnut St, Suite 300, Boulder, CO, USA
| | - Victor R Baker
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - Kevin D Webster
- Planetary Science Institute, 1700 E Fort Lowell Road, Suite 106, Tucson, AZ, USA
| | - Mark Sykes
- Planetary Science Institute, 1700 E Fort Lowell Road, Suite 106, Tucson, AZ, USA
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Quillen AC, Zhao Y, Chen Y, Sánchez P, Nelson RC, Schwartz SR. Impact Excitation of a Seismic Pulse and Vibrational Normal Modes on Asteroid Bennu and Associated Slumping of Regolith. ICARUS 2019; 319:312-333. [PMID: 32908320 PMCID: PMC7477816 DOI: 10.1016/j.icarus.2018.09.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We consider an impact on an asteroid that is energetic enough to cause resurfacing by seismic reverberation and just below the catastrophic disruption threshold, assuming that seismic waves are not rapidly attenuated. In asteroids with diameter less than 1 km we identify a regime where rare energetic impactors can excite seismic waves with frequencies near those of the asteroid's slowest normal modes. In this regime, the distribution of seismic reverberation is not evenly distributed across the body surface. With mass-spring model elastic simulations, we model impact excitation of seismic waves with a force pulse exerted on the surface and using three different asteroid shape models. The simulations exhibit antipodal focusing and normal mode excitation. If the impulse excited vibrational energy is long lasting, vibrations are highest at impact point, its antipode and at high surface elevations such as an equatorial ridge. A near equatorial impact launches a seismic impulse on a non-spherical body that can be focused on two additional points on an the equatorial ridge. We explore simple flow models for the morphology of vibration induced surface slumping. We find that the initial seismic pulse is unlikely to cause large shape changes. Long lasting seismic reverberation on Bennu caused by a near equatorial impact could have raised the height of its equatorial ridge by a few meters and raised two peaks on it, one near impact site and the other near its antipode.
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Affiliation(s)
- Alice C Quillen
- Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA
| | - Yuhui Zhao
- Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, China
| | - YuanYuan Chen
- Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, China
| | - Paul Sánchez
- Colorado Center for Astrodynamics Research, The University of Colorado Boulder, UCB 431, Boulder, CO 80309-0431, United States
| | - Randal C Nelson
- Department of Computer Science, University of Rochester, Rochester, NY 14627, USA
| | - Stephen R Schwartz
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
- Laboratoire Lagrange, Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, C.S. 34229, 06304 Nice Cedex 4, France
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Platz T, Byrne PK, Massironi M, Hiesinger H. Volcanism and tectonism across the inner solar system: an overview. ACTA ACUST UNITED AC 2014. [DOI: 10.1144/sp401.22] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractVolcanism and tectonism are the dominant endogenic means by which planetary surfaces change. This book, in general, and this overview, in particular, aim to encompass the broad range in character of volcanism, tectonism, faulting and associated interactions observed on planetary bodies across the inner solar system – a region that includes Mercury, Venus, Earth, the Moon, Mars and asteroids. The diversity and breadth of landforms produced by volcanic and tectonic processes are enormous, and vary across the inventory of inner solar system bodies. As a result, the selection of prevailing landforms and their underlying formational processes that are described and highlighted in this review are but a primer to the expansive field of planetary volcanism and tectonism. In addition to this extended introductory contribution, this Special Publication features 21 dedicated research articles about volcanic and tectonic processes manifest across the inner solar system. Those articles are summarized at the end of this review.
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Affiliation(s)
- T. Platz
- Planetary Science Institute, 1700 East Fort Lowell Road, Tucson, AZ 85719-2395, USA
- Freie Universität Berlin, Institute of Geological Sciences, Planetary Sciences & Remote Sensing, Malteserstrasse 74-100, 12249 Berlin, Germany
| | - P. K. Byrne
- Lunar and Planetary Institute, Universities Space Research Association, 3600 Bay Area Boulevard, Houston, TX 77058, USA
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015-1305, USA
| | - M. Massironi
- Dipartimento di Geoscienze, Universita' degli Studi di Padova, via G. Gradenigo 6, 35131 Padova, Italy
| | - H. Hiesinger
- Institut für Planetologie, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, 48149 Münster, Germany
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Dzurisin D. The tectonic and volcanic history of mercury as inferred from studies of scarps, ridges, troughs, and other lineaments. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jb083ib10p04883] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Gault DE, Guest JE, Murray JB, Dzurisin D, Malin MC. Some comparisons of impact craters on Mercury and the Moon. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jb080i017p02444] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Marchi S, McSween HY, O'Brien DP, Schenk P, De Sanctis MC, Gaskell R, Jaumann R, Mottola S, Preusker F, Raymond CA, Roatsch T, Russell CT. The violent collisional history of asteroid 4 Vesta. Science 2012; 336:690-4. [PMID: 22582255 DOI: 10.1126/science.1218757] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Vesta is a large differentiated rocky body in the main asteroid belt that accreted within the first few million years after the formation of the earliest solar system solids. The Dawn spacecraft extensively imaged Vesta's surface, revealing a collision-dominated history. Results show that Vesta's cratering record has a strong north-south dichotomy. Vesta's northern heavily cratered terrains retain much of their earliest history. The southern hemisphere was reset, however, by two major collisions in more recent times. We estimate that the youngest of these impact structures, about 500 kilometers across, formed about 1 billion years ago, in agreement with estimates of Vesta asteroid family age based on dynamical and collisional constraints, supporting the notion that the Vesta asteroid family was formed during this event.
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Affiliation(s)
- S Marchi
- NASA Lunar Science Institute, Boulder, CO, USA.
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Hiesinger H, Head JW, Wolf U, Jaumann R, Neukum G. Ages and stratigraphy of lunar mare basalts in Mare Frigoris and other nearside maria based on crater size-frequency distribution measurements. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009je003380] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Richardson JE, Melosh HJ, Greenberg R. Impact-induced seismic activity on asteroid 433 Eros: a surface modification process. Science 2004; 306:1526-9. [PMID: 15567856 DOI: 10.1126/science.1104731] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
High-resolution images of the surface of asteroid 433 Eros revealed evidence of downslope movement of a loose regolith layer, as well as the degradation and erasure of small impact craters (less than approximately 100 meters in diameter). One hypothesis to explain these observations is seismic reverberation after impact events. We used a combination of seismic and geomorphic modeling to analyze the response of regolith-covered topography, particularly craters, to impact-induced seismic shaking. Applying these results to a stochastic cratering model for the surface of Eros produced good agreement with the observed size-frequency distribution of craters, including the paucity of small craters.
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Affiliation(s)
- James E Richardson
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA.
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Halekas JS, Mitchell DL, Lin RP, Frey S, Hood LL, Acuña MH, Binder AB. Mapping of crustal magnetic anomalies on the lunar near side by the Lunar Prospector electron reflectometer. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000je001380] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Wieczorek MA, Zuber MT. A Serenitatis origin for the Imbrian grooves and South Pole-Aitken thorium anomaly. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000je001384] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hood LL, Zakharian A, Halekas J, Mitchell DL, Lin RP, Acuña MH, Binder AB. Initial mapping and interpretation of lunar crustal magnetic anomalies using Lunar Prospector magnetometer data. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000je001366] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Tsikalas F, Gudlaugsson ST, Faleide JI. The anatomy of a buried complex impact structure: The Mjølnir Structure, Barents Sea. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/97jb03389] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lin RP, Mitchell DL, Curtis DW, Anderson KA, Carlson CW, McFadden J, Acuna MH, Hood LL, Binder A. Lunar surface magnetic fields and their interaction with the solar wind: results from lunar prospector. Science 1998; 281:1480-4. [PMID: 9727969 DOI: 10.1126/science.281.5382.1480] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The magnetometer and electron reflectometer experiment on the Lunar Prospector spacecraft has obtained maps of lunar crustal magnetic fields and observed the interaction between the solar wind and regions of strong crustal magnetic fields at high selenographic latitude (30 degreesS to 80 degreesS) and low ( approximately 100 kilometers) altitude. Electron reflection maps of the regions antipodal to the Imbrium and Serenitatis impact basins, extending to 80 degreesS latitude, show that crustal magnetic fields fill most of the antipodal zones of those basins. This finding provides further evidence for the hypothesis that basin-forming impacts result in magnetization of the lunar crust at their antipodes. The crustal magnetic fields of the Imbrium antipode region are strong enough to deflect the solar wind and form a miniature (100 to several hundred kilometers across) magnetosphere, magnetosheath, and bow shock system.
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Affiliation(s)
- RP Lin
- R. P. Lin, Space Sciences Laboratory and Physics Department, University of California, Berkeley, CA 94720, USA. D. L. Mitchell, D. W. Curtis, K. A. Anderson, C. W. Carlson, J. McFadden, Space Sciences Laboratory, University of California
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Clifford SM. A model for the hydrologic and climatic behavior of water on Mars. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/93je00225] [Citation(s) in RCA: 555] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Schaber GG, Strom RG, Moore HJ, Soderblom LA, Kirk RL, Chadwick DJ, Dawson DD, Gaddis LR, Boyce JM, Russell J. Geology and distribution of impact craters on Venus: What are they telling us? ACTA ACUST UNITED AC 1992. [DOI: 10.1029/92je01246] [Citation(s) in RCA: 331] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Hood LL, Huang Z. Formation of magnetic anomalies antipodal to lunar impact basins: Two-dimensional model calculations. ACTA ACUST UNITED AC 1991. [DOI: 10.1029/91jb00308] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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21
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Sprague AL, Kozlowski RW, Hunten DM. Caloris Basin: An Enhanced Source for Potassium in Mercury's Atmosphere. Science 1990; 249:1140-3. [PMID: 17831982 DOI: 10.1126/science.249.4973.1140] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Enhanced abundances of neutral potassium (K) in the atmosphere of Mercury have been found above the longitude range containing Caloris Basin. Results of a large data set including six elongations of the planet between June 1986 and January 1988 show typical K column abundances of approximately 5.4 x 10(8) K atoms/cm(2). During the observing period in October 1987, when Caloris Basin was in view, the typical K column was approximately 2.7 x 10(9) K atoms/cm(2). Another large value (2.1 x 10(9) K atoms/cm(2)) was seen over the Caloris antipode in January 1988. This enhancement is consistent with an increased source of K from the well-fractured crust and regolith associated with this large impact basin. The phenomenon is localized because at most solar angles, thermal alkali atoms cannot move more than a few hundred kilometers from their source before being lost to ionization by solar ultraviolet radiation.
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Spudis PD, Hawke BR, Lucey P. Composition of orientale basin deposits and implications for the lunar basin-forming process. ACTA ACUST UNITED AC 1984. [DOI: 10.1029/jb089is01p0c197] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
The style and evolution of tectonics on the terrestrial planets differ substantially. The style is related to the thickness of the lithosphere and to whether the lithosphere is divided into distinct, mobile plates that can be recycled into the mantle, as on Earth, or is a single spherical shell, as on the moon, Mars, and Mercury. The evolution of a planetary lithosphere and the development of plate tectonics appear to be influenced by several factors, including planetary size, chemistry, and external and internal heat sources. Vertical tectonic movement due to lithospheric loading or uplift is similar on all of the terrestrial planets and is controlled by the local thickness and rheology of the lithosphere. The surface of Venus, although known only at low resolution, displays features both similar to those on Earth (mountain belts, high plateaus) and similar to those on the smaller planets (possible impact basins). Improved understanding of the tectonic evolution of Venus will permit an evaluation of the relative roles of planetary size and chemistry in determining evolutionary style.
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Cometary collisions on the Moon and Mercury (reply). Nature 1980. [DOI: 10.1038/287086b0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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