Matching Items (6)
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Description
Affect is a domain of psychology that includes attitudes, emotions, interests, and values. My own affect influenced the choice of topics for my dissertation. After examining asteroid interiors and the Moon’s thermal evolution, I discuss the role of affect in online science education. I begin with asteroids, which are collections of smaller objects held together by gravity and possibly cohesion. These “rubble-pile” objects may experience the Brazil Nut Effect (BNE). When a collection of particles of similar densities, but of different sizes, is shaken, smaller particles will move parallel to the local gravity vector while larger objects will do the opposite. Thus, when asteroids are shaken by impacts, they may experience the BNE as possibly evidenced by large boulders seen on their surfaces. I found while the BNE is plausible on asteroids, it is confined to only the outer layers. The Moon, which formed with a Lunar Magma Ocean (LMO), is the next topic of this work. The LMO is due to the Moon forming rapidly after a giant impact between the proto-Earth and another planetary body. The first 80% of the LMO solidified rapidly at which point a floatation crust formed and slowed solidification of the remaining LMO. Impact bombardment during this cooling process, while an important component, has not been studied in detail. Impacts considered here are from debris generated during the formation of the Moon. I developed a thermal model that incorporates impacts and find that impacts may have either expedited or delayed LMO solidification. Finally, I return to affect to consider the differences in attitudes towards science between students enrolled in fully-online degree programs and those enrolled in traditional, in-person degree programs. I analyzed pre- and post-course survey data from the online astrobiology course Habitable Worlds. Unlike their traditional program counterparts, students enrolled in online programs started the course with better attitudes towards science and also further changed towards more positive attitudes during the course. Along with important conclusions in three research fields, this work aims to demonstrate the importance of affect in both scientific research and science education.
ContributorsDingatantrige Perera, Jude Viranga (Author) / Asphaug, Erik (Thesis advisor) / Semken, Steven (Thesis advisor) / Anbar, Ariel (Committee member) / Elkins-Tanton, Linda T. (Committee member) / Robinson, Mark (Committee member) / Arizona State University (Publisher)
Created2017
Description
On Mars, sedimentary deposits reveal a complex history of water- and wind-related geologic processes. Central mounds – kilometer-scale stacks of sediment located within craters – occur across Mars, but the specific processes responsible for mound formation and subsequent modification are still uncertain. A survey of central mounds within large craters was conducted. Mound locations, mound offsets within their host craters, and relative mound heights were used to address various mound formation hypotheses. The results suggest that mound sediments once filled their host craters and were later eroded into the features observed today. Mounds offsets from the center of their host crater imply that wind caused the erosion of central mounds. An in depth study of a single central mound (Mt. Sharp within Gale crater) was also conducted. Thermal Emission Imaging System Visible Imaging Subsystem (THEMIS-VIS) mosaics in grayscale and false color were used to characterize the morphology and color variations in and around Gale crater. One result of this study is that dunes within Gale crater vary in false color composites from blue to purple, and that these color differences may be due to changes in dust cover, grain size, and/or composition. To further investigate dune fields on Mars, albedo variations at eight dune fields were studied based on the hypothesis that a dune’s ripple migration rate is correlated to its albedo. This study concluded that a dune’s minimum albedo does not have a simple correlation with its ripple migration rate. Instead, dust devils remove dust on slow-moving and immobile dunes, whereas saltating sand caused by strong winds removes dust on faster-moving dunes.
On the Moon, explosive volcanic deposits within Oppenheimer crater that were emplaced ballistically were investigated. Lunar Reconnaissance Orbiter (LRO) Diviner Radiometer mid-infrared data, LRO Camera images, and Chandrayaan-1 orbiter Moon Mineralogy Mapper near-infrared spectra were used to test the hypothesis that the pyroclastic deposits in Oppenheimer crater were emplaced via Vulcanian activity by constraining their composition and mineralogy. The mineralogy and iron-content of the pyroclastic deposits vary significantly (including examples of potentially very high iron compositions), which indicates variability in eruption style. These results suggest that localized lunar pyroclastic deposits may have a more complex origin and mode of emplacement than previously thought.
On the Moon, explosive volcanic deposits within Oppenheimer crater that were emplaced ballistically were investigated. Lunar Reconnaissance Orbiter (LRO) Diviner Radiometer mid-infrared data, LRO Camera images, and Chandrayaan-1 orbiter Moon Mineralogy Mapper near-infrared spectra were used to test the hypothesis that the pyroclastic deposits in Oppenheimer crater were emplaced via Vulcanian activity by constraining their composition and mineralogy. The mineralogy and iron-content of the pyroclastic deposits vary significantly (including examples of potentially very high iron compositions), which indicates variability in eruption style. These results suggest that localized lunar pyroclastic deposits may have a more complex origin and mode of emplacement than previously thought.
ContributorsBennett, Kristen Alicia (Author) / Bell, James F. (Thesis advisor) / Christensen, Phillip (Committee member) / Clarke, Amanda (Committee member) / Robinson, Mark (Committee member) / Whipple, Kelin (Committee member) / Arizona State University (Publisher)
Created2016
ContributorsKoloch, Bradley (Performer) / Robinson, Mark (Performer) / Shaffer, Richard (Performer) / Woodrow, Marie (Performer) / Samuel, Christopher (Performer) / Listerud, L. Brian (Performer) / Graduate Chorale (Performer) / Recital Chorale (Performer) / ASU Library. Music Library (Publisher)
Created1989-11-16
ContributorsWeber, Steven T (Performer) / Robinson, Mark (Performer) / Copeland, Jill (Performer) / Darrough, Galen P. (Performer) / Nemko, Deborah (Performer) / Arizona Statesmen (Performer) / Women's Choir (Performer) / ASU Library. Music Library (Publisher)
Created1990-04-26
ContributorsRobinson, Mark (Conductor) / Shryock, Darin W. (Conductor) / Shaffer, Richard (Conductor) / Topping, David (Conductor) / Engelson, Robert (Performer) / Kelly, Kathleen (Performer) / Graduate Chorale (Performer) / Recital Chorale (Performer) / ASU Library. Music Library (Publisher)
Created1989-02-23
ContributorsMeredith, Steve (Performer) / Fuller, Charles L. (Performer) / Ethridge, Brandon (Performer) / Hloucal, Amy (Performer) / Robinson, Mark (Performer) / Women's Choir (Performer) / Arizona Statesmen (Performer) / ASU Library. Music Library (Publisher)
Created1989-03-02