Forty-first Lunar and Planetary Science Conference

Special sessions were: A New Moon: Lunar Reconnaissance Orbiter Results ; Water in the Solar System: Incorporation into Primitive Bodies and Evolution ; A New Moon: LCROSS, Chandrayaan, and Chang-E-1 ; Water in the Solar System: Moon ; A New Moon: Spectral Constraints on Lunar Crustal Composition ; Characterizing Near-Earth Objects ; A New Moon: Lunar Volcanism and Impact. This CD-ROM contains the contents, program, abstracts, and author indexes for the 41st Lunar and Planetary Science Conference.by Lunar and Planetary Institute, NASA Johnson Space Centerconference co-chairs, Stephen Mackwell, Lunar and Planetary Institute [and] Eileen Stansbery, NASA Johnson Space Center.PARTIAL CONTENTS: Roughness and Radar Polarimetry of Lunar Polar Craters: Testing for Ice Deposits / B.J. Thomson, P.D. Spudis, D.B.J. Bussey, L. Carter, R.L. Kirk, C. Neish, G. Patterson, R.K. Raney, H. Winters, and the Mini-RF Team--Formation of Jupiter's Atmosphere from a Supernova-Contaminated Molecular Cloud / H.B. Throop--Ancient Lunar Dynamo: Absence of Evidence is Not the Evidence of Absence / S.M. Tikoo, B.P. Weiss, J. Buz, I. Garrick-Bethell, T.L. Grove, and J. Gattaccaea--Dark Dunes in Ka'u Desert (Hawaii) as Terrestrial Analogs to Dark Dunes on Mars / D. Tirsch, R.A. Craddock, and R. Jaumann--Mars Ice Condensation and Density Orbiter / T.N. Titus, T. Prettyman, A. Brown, T.I. Michaels, and A. Colaprete--The Atacama Desert Cave Shredder: A Case for Conduction Thermodynamics / T.N. Titus, J.J. Wynne, D. Ruby, and N. Cabrol

Understanding the Composition and Evolution of the Lunar Surface Through Laboratory Space Weathering Simulations and Remote Sensing

Ph.D

Ring-Moat Dome Structures (RMDSs) in the Lunar Maria:Statistical, Compositional, and Morphological Characterization and Assessment of Theories of Origin

Ring-moat dome structures (RMDSs) are positive morphologic features found clustered across many mare regions on the Moon, of which only a few isolated examples have been previously reported. Our continuing survey has expanded the known locations of the RMDSs from ~2,600 to over 8,000, indicating that RMDSs are more common geological features than previously thought. This work presents a detailed geomorphological analysis of 532 RMDSs identified in several mare basins. The combination of detailed elemental mapping, morphological and morphometric analyses, spatial distribution relationships with other geologic structures, and comparison with terrestrial analogs lead us to conclude that (1) RMDSs represent low circular mounds with diameters of a few hundred meters (average about 200 m) and a mean height of 3.5 m. The mounds are surrounded by moats ranging from tens to over 100 m in width and up to several meters in depth; (2) there is a wide variation of titanium abundances, although RMDSs are more commonly found in mare regions of moderate-to-high titanium content (>3 wt% TiO2); (3) RMDSs are found to occur on or around fractures, graben, and volcanic edifices (small shields and cones); (4) a spatial association between RMDSs and Irregular Mare Patches (see Braden et al., 2014, https://doi.org/10.1038/ngeo2252) is observed, suggesting that both may form from related lava flows; (5) comparisons between RMDSs and lava inflationary structures on Earth support an inflation-related extrusive nature and a genetic relationship with host lava flow processes; and (6) RMDS embayment relationships with craters of different degradation ages superposed on the host mare, and regolith development models, produces conflicting age relationships and divide theories of RMDS origin into two categories, (1) synchronous with the emplacement and cooling of the host lava flows ~3–4 Ga and (2) emplaced substantially after the host mare lava unit, in the period ~0–3 Ga. We outline the evidence supporting this age conundrum and implications for the different theories of origin and describe future research avenues to help resolve these outstanding questions. ©2020. American Geophysical Union. All Rights Reserved

Program and Abstracts

The New Views of the Moon 2--Europe workshop is designed for presenting updates from the various chapter leads as to the current state of each chapter, and also for new science and exploration results as they relate to the existing chapters and integrating them--contributed talks are therefore essential and welcomed. NVM-2 Europe is critical for getting the chapters integrated with each other and close to the final form, as well as formalizing writing teams.Organizers: Lunar and Planetary Institute, University of Münster ; Conveners: Clive Neal, University of Notre Dame, Harald Hiesinger, Westfälische Wilhelms-Universität, Institut für Planetologie, University of Münster ; Organizing Committee: Lisa Gaddis, U.S. Geological Survey [and 5 others

Fortieth Lunar and Planetary Science Conference

Special sessions on Lunar Missions, Messenger at Mercury, and Icy Satellites of Jupiter and Saturn were held. This CD-ROM contains the contents, program, abstracts, and author indexes for the 40th Lunar and Planetary Science Conference.sponsored by Lunar and Planetary Institute, NASA Johnson Space Centerconference co-chairs, Stephen J. Mackwell, Eileen StansberyPARTIAL CONTENTS: Equilibrated Aggregates in Cometary IDPs: Insights into the Crystallization Process in Protoplanetary Disks / L.P. Keller and S. Messenger--The Impact Crater Jebel Waqf as Suwwan in Jordan: Effects of Target Heterogeneity and Impact Obliquity on Central Uplift Formation / T. Kenkmann, W.U. Reimold, M. Khirfan, E. Salameh, K. Konsul, T. Lehmann, and H. Khoury--The Dispersal of Pyroclasts from Apollinaris Patera, Mars / L. Kerber, J.W. Head, J.B. Madeleine, F. Forget, and L. Wilson--The Age of the Medusae Fossae Formation: Reassessment Using Lava Flow Cast and Mold Contacts / L. Kerber and J.W. Head III--Possible Liquid-like Water Produced Seepage Features on Mars / A. Kereszturi, A. Horváth, A. Sik, A. Kuti, Sz. Bérczi, T. Gánti, T. Pócs, and E. Szathmáry

Proceedings Of The 18th Annual Meeting Of The Asia Oceania Geosciences Society (Aogs 2021)

The 18th Annual Meeting of the Asia Oceania Geosciences Society (AOGS 2021) was held from 1st to 6th August 2021. This proceedings volume includes selected extended abstracts from a challenging array of presentations at this conference. The AOGS Annual Meeting is a leading venue for professional interaction among researchers and practitioners, covering diverse disciplines of geosciences

Examination of volcanism and impact cratering on terrestrial bodies

Thesis (Ph.D.) University of Alaska Fairbanks, 2023Exploring and expanding our understanding of the planets (i.e., planetary science) encompasses a vast array of topics and disciplines. This dissertation concentrates on the surficial processes of and examination of terrestrial planets, primarily via the study of volcanism and impact cratering. The first project starts with an exploration of NIR remote sensing techniques as applied to Venus. This work found that NIR remote sensing at the clement conditions just beneath the cloud deck provide vastly improved imaging capability. This improved visibility is most notable for the tesserae, regions of Venus of great interest to the scientific community. Radar imagery and derived data products were then used to survey 21 mid-sized volcanoes on the surface of Venus. Similar to volcanoes at larger diameters, the midsized volcanoes of Venus are significantly flatter than those on other terrestrial bodies. Several of these volcanoes also show deformation that requires a negligibly thin lithosphere some time after the emplacement of the construct. The third project then evaluates the hazards involved with safely placing a lander on the Venusian tesserae and examines potential methods by which to detect and then avoid these hazards. Safely placing a suite of scientific instruments on tesserae is necessary to answer long-standing questions about Venus. Current technologies put relevant hazards at the edge of detection (i.e., zero fault tolerance) and can execute divert maneuvers of only a few tens of meters. Investment in hazard detection and avoidance technologies is necessary to bring safety margins to acceptable levels; data from future missions - while helpful - will be insufficient to select safe landing zones prior to launch. Oblique impact cratering is a ubiquitous event (approximately half of all impacts are at 45 or less). Our poor understanding of this process leaves a significant amount of information buried and waiting to be uncovered. Low-velocity oblique impact experiments were conducted at John's Hopkins University's Applied Physics Laboratory Planetary Impact Lab to better understand the oblique impact process and prepare for high velocity experiments at similar impact angles. These experiments also sought to understand the effect of target tilt, which is currently necessary at existing experimental facilities in order to simulate changes in impact angle smaller than 15°. These experiments show that target tilt significantly amplifies oblique characteristics (e.g., aspect ratio, butterfly ejecta). The time-delayed and spatially offset transference of energy from the impactor to the target is important in determining the excavation process and final crater morphology and ejecta distribution