Space Weathering of Rocks

Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. On the Moon, rocks make up only a very small percentage of the exposed surface and areas where rocks are exposed, like central peaks, are often among the least space weathered regions we find in remote sensing data. However, our studies of weathered Ap 17 rocks 76015 and 76237 show that significant amounts of weathering products can build up on rock surfaces. Because rocks have much longer surface lifetimes than an individual soil grain, and thus record a longer history of exposure, we can study these products to gain a deeper perspective on the weathering process and better assess the relative impo!1ance of various weathering components on the Moon. In contrast to the lunar case, on small asteroids, like Itokowa, rocks make up a large fraction of the exposed surface. Results from the Hayabusa spacecraft at Itokowa suggest that while the low gravity does not allow for the development of a mature regolith, weathering patinas can and do develop on rock surfaces, in fact, the rocky surfaces were seen to be darker and appear spectrally more weathered than regions with finer materials. To explore how weathering of asteroidal rocks may differ from lunar, a set of ordinary chondrite meteorites (H, L, and LL) which have been subjected to artificial space weathering by nanopulse laser were examined by TEM. NpFe(sup 0) bearing glasses were ubiquitous in both the naturally-weathered lunar and the artificially-weathered meteorite samples

The Uppermost Surface of the Moon

The Ap16 Clam shell Sampling Devices (CSSDs) were designed to sample the uppermost surface of lunar soil. The two devices used beta cloth (69003) and velvet (69004) to collect soil from the top 100 and 500 micrometers of the soil, respectively. Due to the difficulty of the sampling method, little material was collected and as a result little research has been done on these samples. Initial studies attempted to look at the material which had fallen off of the fabrics and was subsequently collected from inside the sample containers. However, this material was highly fractionated and did not provide an adequate picture of the uppermost surface. Recently, samples were obtained directly from the beta cloth using carbon tape. While still fractionated, these samples provide a unique glimpse into the undisturbed soil exposed at the lunar surface

Examining the Uppermost Surface of the Moon

Understanding the properties of the uppermost lunar surface is critical as it is the optical surface that is probed by remote-sensing data, like that which is and will be generated by instruments on orbiting missions (e.g. M3, LRO). The uppermost material is also the surface with which future lunar astronauts and their equipment will be in direct contact, and thus understanding its properties will be important for dust mitigation and toxicology issues. Furthermore, exploring the properties of this uppermost surface may provide insight into conditions at this crucial interface, such as grain charging and levitatio

The bryoflora of Falls Branch Falls, Cherokee National Forest, Monroe County, Tennessee, USA

The bryophytes of Falls Branch Falls were sampled over two field seasons, 2000-2001. Falls Branch Scenic Area lies within the Citico Wilderness of Cherokee National Forest, Monroe County, Tennessee, USA. One thousand eight hundred seventy one (1871) record entries from 707 samples collected contained 49 families; 91 genera and 145 species representing 79 mosses; 65 liverworts and one hornwort. This study resulted in 7 6 new Monroe County bryophyte records. Bryophytes were sampled/inventoried within the riparian, spray and other wet zones of Falls Branch Falls, Cherokee National Forest, Monroe County, Tennessee. Environmental factors of substrate, moisture level and light intensity were noted. The streambed of Falls Branch was sampled along East, Center and West transects from 30 meters above the falls to a few meters beyond Split Rock Crossing, a distance of approximately 100 meters. Bryophyte components of each sample were identified and ranked according to approximate proportion present. The most intensively sampled environmental gradient was also the most abundant, shaded wet rock. Phytogeography of the taxa present ranged from narrow Southern Appalachian endemics to cosmopolitan taxa and populations disjunct from Asia, Europe and the Pacific Northwest. Several taxa also exhibited northern/boreal or southern affinities. Bryophytes were analyzed using SPSS TwoStep Cluster Analysis which sorted the taxa into 11 categorical clusters along environmental gradients. The same 11 clusters were generated using both the entire data set and only the most dominant taxa, sampled 25 times or more. The 11 clusters were arranged into a dendrogram of community, society, and facies structures based on environmental gradients and most dominant taxa. The Pisces Community Analysis package, containing TWINSP AN and Reciprocal Averaging analytical programs were applied to the data for further analysis. These analyses delineated associations of taxa between Rock and Non-Rock substrates. Among Non-Rock substrates further distinctions existed comparing taxa affiliated with Soil, Humus, Logs, and Trees. A final analysis, comparing the dominant species associations of the east, center, and west transects of the riparian zone, did not support separate divisions of associated taxa within the zone

Space Weathering in the Inner Solar System

"Space weathering" is the term given to the cumulative effects incurred by surfaces which are exposed to the harsh environment of space. Lunar sample studies over the last decade or so have produced a clear picture of space weathering processes in the lunar environment. By combining laboratory and remote spectra with microanalytical methods (scanning and transmission electron microscopy), we have begun to unravel the various processes (irradiation, micrometeorite bombardment, etc) that contribute to space weathering and the physical and optical consequences of those processes on the Moon. Using the understanding gleaned from lunar samples, it is possible to extrapolate weathering processes to other airless bodies from which we have not yet returned samples (i.e. Mercury, asteroids). Through experiments which simulate various components of weathering, the expected differences in environment (impact rate, distance from Sun, presence of a magnetic field, reduced or enhanced gravity, etc) and composition (particularly iron content) can be explored to understand how space weathering will manifest on a given body

Through Google-Colored Glass(es): Design, Emotion, Class, and Wearables as Commodity and Control

This chapter discusses the implications of wearable technologies like Google Glass that function as a tool for occupying, commodifying, and profiting from the bio- logical, psychological, and emotional data of its wearers and those who fall within its gaze. We argue that Google Glass privileges an imaginary of unbridled exploration and intrusion into the physical and emotional space of others. Glass’s recognizable esthetic and outward-facing camera has elicited intense emotional response, partic- ularly when “exploration” has taken place in areas of San Francisco occupied by residents who were finding themselves priced out or evicted from their homes to make way for the techno-elite. We find that very few trade and popular press articles have focused on the failure of Glass along these dimensions, while the surveillance and class-based aspects of Google Glass are fundamental to an accurate rendering of the product’s trajectory and the public’s emotional response to this product. The goal of this chapter is to foreground dimensions of surveillance and economics, class and resistance, in the face of unending rollouts of new wearable products designed to integrate seamlessly with everyday life—for those, of course, who can afford them. Ultimately, we believe more nuanced, intersectional analyses of power along race, class, and gender must be at the forefront of future research on wearable technologies. Our goal is to raise important critiques of the commodification of emotions, and the expansion of the surveillance state vis-à-vis Google’s increasing and unrivaled information empire, the longstanding social costs of which have yet to be fully articulated

Empowered to Name, Inspired to Act: Social Responsibility and Diversity as Calls to Action in the LIS Context

Social responsibility and diversity are two principle tenets of the field of library and information science (LIS), as defined by the American Library Association’s Core Values of Librarianship document, yet often remain on the margins of LIS education, leading to limited student engagement with these concepts and to limited faculty modeling of socially responsible interventions. In this paper, we take up the need to increase the role of both in articulating the values of diversity and social responsibility in LIS education, and argue the field should broaden to put LIS students and faculty in dialog with contemporary social issues of social inequality and injustice whenever possible. We also examine two specific cases of socially responsible activism spearheaded by LIS faculty and how these experiences shape, and are shaped by, curricular commitments to addressing the values of social responsibility and diversity in LIS in the classroom and through research. The development of a social responsibility orientation and skillset, along with literacies of diversity, we argue, leads to better-prepared practitioners and an LIS community that is more actively engaged with its environment. The impetus for students to act can be empowered by faculty modeling a commitment to social responsibility and diversity in their own professional lives

Examining the Uppermost Surface of the Lunar Regolith

This slide presentation reviews the examination of the uppermost surface of the lunar regolith. It shows the mechanism (i.e. a Clam Shell Sampling Device) that was used to retrieve samples of the surface of the lunar soil. Samples were obtained from the devices, and they were examined in the scanning electron microscope (SEM). Using a lunar simulant, JSC-1a, test were run to ascertain if the sample from the clam shell device were biased due to the collection. The results of the test were that all the fine grains analyzed to the limit of the capabilities were found to be lunar in composition, though non-lunar contaminants may exist in the submicron population. Further work is required, though the initial study shows that the uppermost surface is enriched in fine (< 2 micron grains) compared to the bulk soil

The Lunar Regolith

A thick layer of regolith, fragmental and unconsolidated rock material, covers the entire lunar surface. This layer is the result of the continuous impact of meteoroids large and small and the steady bombardment of charged particles from the sun and stars. The regolith is generally about 4-5 m thick in mare regions and 10-15 m in highland areas (McKay et al., 1991) and contains all sizes of material from large boulders to sub-micron dust particles. Below the regolith is a region of large blocks of material, large-scale ejecta and brecciated bedrock, often referred to as the "megaregolith". Lunar soil is a term often used interchangeably with regolith, however, soil is defined as the subcentimeter fraction of the regolith (in practice though, soil generally refers to the submillimeter fraction of the regolith). Lunar dust has been defined in many ways by different researchers, but generally refers to only the very finest fractions of the soil, less than approx.10 or 20 microns. Lunar soil can be a misleading term, as lunar "soil" bears little in common with terrestrial soils. Lunar soil contains no organic matter and is not formed through biologic or chemical means as terrestrial soils are, but strictly through mechanical comminution from meteoroids and interaction with the solar wind and other energetic particles. Lunar soils are also not exposed to the wind and water that shapes the Earth. As a consequence, in contrast to terrestrial soils, lunar soils are not sorted in any way, by size, shape, or chemistry. Finally, without wind and water to wear down the edges, lunar soil grains tend to be sharp with fresh fractured surfaces