Reports of planetary geology and geophysics program, 1989

Abstracts of reports from Principal Investigators of NASA's Planetary Geology and Geophysics Program are compiled. The research conducted under this program during 1989 is summarized. Each report includes significant accomplishments in the area of the author's funded grant or contract

Roving vehicle motion control Final report

Roving vehicle motion control for unmanned planetary and lunar exploratio

Reports of planetary geology and geophysics program, 1987

This is a compilation of abstracts of reports from Principal Investigators of NASA's PLanetary Geology and Geophysics program, Office of Space Science and Applications. The purpose is to document in summary form research work conducted in this program during 1987. Each report reflects significant accomplishments in the area of the author's funded grant or contract

Program and abstracts

The workshop will bring together researchers with interests in planetary dunes from diverse backgrounds in image analysis, modeling, and terrestrial analogue studies.National Aeronautics and Space Administration, Universities Space Research Association, Lunar and Planetary Institute, NASA’s Planetary Dunes Programconvener, Timothy Titus ; scientific organizing committee Timothy Titus ... [and others]PARTIAL CONTENTS: The Answer is Blowin in the Wind: The Remarkable Aeolian Career of Ronald Greeley / J.R. Zimbelman--Source-to-Sink: Comparison of Boundary Conditions for Planetary Aeolian Systems / R.C. Ewing--The Relationships Between Dune-Dune Interactions, Boundary Conditions and Dune Field Development, Al Liwa Basin, the Empty Quarter / M.A. Bishop--Reconstruction of Eolian Bedforms and Paleocurrents at Meridiani Planum, Mars / L.A. Edgar

Utilizing Science and Technology to Enhance a Future Planetary Mission: Applications to Europa

abstract: A thorough understanding of Europa's geology through the synergy of science and technology, by combining geologic mapping with autonomous onboard processing methods, enhances the science potential of future outer solar system missions. Mapping outlines the current state of knowledge of Europa's surface and near sub-surface, indicates the prevalence of distinctive geologic features, and enables a uniform perspective of formation mechanisms responsible for generating those features. I have produced a global geologic map of Europa at 1:15 million scale and appraised formation scenarios with respect to conditions necessary to produce observed morphologies and variability of those conditions over Europa's visible geologic history. Mapping identifies areas of interest relevant for autonomous study; it serves as an index for change detection and classification and aids pre-encounter targeting. Therefore, determining the detectability of geophysical activity is essential. Activity is evident by the presence of volcanic plumes or outgassing, disrupted surface morphologies, or changes in morphology, color, temperature, or composition; these characteristics reflect important constraints on the interior dynamics and evolutions of planetary bodies. By adapting machine learning and data mining techniques to signatures of plumes, morphology, and spectra, I have successfully demonstrated autonomous rule-based response and detection, identification, and classification of known events and features on outer planetary bodies using the following methods: 1. Edge-detection, which identifies the planetary horizon and highlights features extending beyond the limb; 2. Spectral matching using a superpixel endmember detection algorithm that identifies mean spectral signatures; and 3. Scale invariant feature transforms combined with supervised classification, which examines brightness gradients throughout an image, highlights extreme gradient regions, and classifies those regions based on a manually selected library of features. I have demonstrated autonomous: detection of volcanic plumes or jets at Io, Enceladus, and several comets, correlation between spectral signatures and morphological appearances of Europa's individual tectonic features, detection of ≤94% of known transient events on multiple planetary bodies, and classification of similar geologic features. Applying these results to conditions expected for Europa enables a prediction of the potential for detection and recommendations for mission concepts to increase the science return and efficiency of future missions to observe Europa.Dissertation/ThesisPh.D. Geological Sciences 201

Visualizing and Understanding Tectonism and Volcanism on Earth and Other Terrestrial Bodies

This dissertation presents new methods of visualizing, teaching, assessing, modeling, and understanding tectonics on Earth and other celestial bodies. Tectonics is the study of planetary lithospheres and includes impact, plate, plume, cryo- and gravitational mechanisms. This dissertation is concerned with plate tectonics and plate/mantle plume interactions. Plate tectonics describes the mainly horizontal motion of lithospheric plates over the asthenosphere. Lithosphere is created at ridges and consumed at subduction zones. In addition to the plate tectonic system, mantle plumes also contribute to mass motions in the subsurface Earth. Both plate tectonics and plume upwelling processes help shape the present form of the planetary surface, including long volcanic island chains, deep ocean basins, and plate boundary triple junctions. Better understanding of these processes by visualization and numerical modeling is one of the primary goals of this study. In the geospatial analysis lab at ODU, our research methodology starts with the creation of visualizations for teaching. These include Google Earth-based virtual field explorations enhanced with digitized specimens and emergent geological and geophysical cross sections. We test these in classes with IRB compliance and sometimes this leads to the discovery of tectonic research questions which we then explore. Settings studied in this investigation are Tonga Trench in the western Pacific Ocean, Artemis on Venus, the Hawaiian-Emperor seamount chain, and the Azores triple junction. Some of these cases pose specific geophysical problems that were selected for further study. The Tonga Trench is a subduction zone that includes trench rollback and opening of a marginal basin—the Lau Basin. The rollback process is difficult to imagine, and therefore we created a set of instructional resources using COLLADA models and the Google Earth Application Programming Interface (API). Animated models for the assessments tests and exploration of different initiations of the subduction process led to a new alternative hypothesis for rollback. Virtual field explorations required the development of new interface features for the Google Earth API. All these instructional materials were combined into modular multi-user virtual field trip experiences and were subject to IRB-compliant evaluation of learning outcomes. Animated COLLADA models for the Hawaii Islands and Emperor Seamounts helped explain the origin and time progression of the island chain. From seismic data, a three-dimensional reconstruction of the Hawaiian mantle plume was created raising the question of the horizontal advection of the plume conduit in the mantle and its correlation with the change in trend of the islands. The Hawaiian–Emperor chain on Earth is spread out as the Pacific plate is moving over the Hawaiian mantle plume. On Venus, however, the Artemis structure was able to grow to super-plume size due to the absence of plate motion. For Venus, visualization was done on a much larger scale, including cross sections of the whole plate showing large plume structures, and Magellan SARS imagery of surface features. In the Azores triple junction, dispersion of plume material is influenced by plate boundary geometry, creating anomalies in seafloor geophysical data for several hundred kilometers away from the plume center. To explore the interaction between a mantle plume and a plate boundary triple junction, a series of three dimensional finite element numerical models was calculated. A parameter space investigation changed the location of the plume conduit and its volume flux, as well as the treatment of viscosity. Flow patterns, dynamical topography, relative crustal thickness variations and waist width scaling relationships resulting from these calculations give valuable insight into the importance of triple junction configuration in the dispersion of plume material

The tectonics of intraplate regions: Quantifying stress and surface deformation in the central and eastern U.S. and planetary analogs on Mercury and the Moon

Occurring ~ 1 year apart, the magnitude 3.4 Germantown, Maryland, (16 July 2010) and magnitude 5.8 Mineral, Virginia, (23 August 2011) earthquakes rocked the U.S. national capital region, drawing renewed attention to the occurrence of seismicity within continental interiors. While the majority of earthquakes concentrate at tectonic plate boundaries, the processes that promote spatially diffuse zones of seismicity in intraplate regions are not well understood. The Mineral earthquake was one of the largest earthquakes to occur east of the Rocky Mountains in the past century and offers a rare opportunity to examine the role of stress transfer, long-distance triggering, and aftershock decay within an intraplate region. Stress transfer from the Mineral and Germantown earthquakes relieved stress on the majority of Cenozoic faults in the Mid-Atlantic region, moving these faults further away from future failure. The Everona fault and southern portion of the Mountain Run fault zone were the only locations (except in the aftershock region) that were loaded from the Mineral earthquake, although by only ~1 mbar. Accumulation of stress over time is required in order to significantly affect regional seismicity. There is no evidence of remote triggering due to the passage of seismic waves in any of the major seismic zones in the central and eastern U.S. However, the slow decay rate of aftershocks suggests seismicity in the epicentral region might continue for a decade or longer. Aftershocks triggered by stress imparted by the mainshock imply that Coulomb stress transfer plays an important role in earthquake triggering processes within intraplate regions. Processes in the aftershock zone likely have the greatest influence on seismic hazard. New imagery and altimetry data returned from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) and Lunar Reconnaissance Orbiter (LRO) spacecraft provide new insight into processes driving intraplate tectonic deformation. Mercurian wrinkle ridges are ~2.2 larger in mean relief than wrinkle ridges on the Moon, suggesting a larger component of global contraction on Mercury. Patterns of faulting on Mercury and the Moon, as well as in the central and eastern U.S., indicate that intraplate seismicity can concentrate in zones of pre-existing weakness and spatially migrate

Planetary Science Vision 2050 Workshop : February 27–28 and March 1, 2017, Washington, DC

This workshop is meant to provide NASA’s Planetary Science Division with a very long-range vision of what planetary science may look like in the future.Organizer, Lunar and Planetary Institute ; Conveners, James Green, NASA Planetary Science Division, Doris Daou, NASA Planetary Science Division ; Science Organizing Committee, Stephen Mackwell, Universities Space Research Association [and 14 others]PARTIAL CONTENTS: Exploration Missions to the Kuiper Belt and Oort Cloud--Future Mercury Exploration: Unique Science Opportunities from Our Solar System’s Innermost Planet--A Vision for Ice Giant Exploration--BAOBAB (Big and Outrageously Bold Asteroid Belt) Project--Asteroid Studies: A 35-Year Forecast--Sampling the Solar System: The Next Level of Understanding--A Ground Truth-Based Approach to Future Solar System Origins Research--Isotope Geochemistry for Comparative Planetology of Exoplanets--The Moon as a Laboratory for Biological Contamination Research--“Be Careful What You Wish For:” The Scientific, Practical, and Cultural Implications of Discovering Life in Our Solar System--The Importance of Particle Induced X-Ray Emission (PIXE) Analysis and Imaging to the Search for Life on the Ocean Worlds--Follow the (Outer Solar System) Water: Program Options to Explore Ocean Worlds--Analogies Among Current and Future Life Detection Missions and the Pharmaceutical/ Biomedical Industries--On Neuromorphic Architectures for Efficient, Robust, and Adaptable Autonomy in Life Detection and Other Deep Space Missions