New Paradigms For Asteroid Formation

Asteroids and meteorites provide key evidence on the formation of planetesimals in the Solar System. Asteroids are traditionally thought to form in a bottom-up process by coagulation within a population of initially km-scale planetesimals. However, new models challenge this idea by demonstrating that asteroids of sizes from 100 to 1000 km can form directly from the gravitational collapse of small particles which have organised themselves in dense filaments and clusters in the turbulent gas. Particles concentrate passively between eddies down to the smallest scales of the turbulent gas flow and inside large-scale pressure bumps and vortices. The streaming instability causes particles to take an active role in the concentration, by piling up in dense filaments whose friction on the gas reduces the radial drift compared to that of isolated particles. In this chapter we review new paradigms for asteroid formation and compare critically against the observed properties of asteroids as well as constraints from meteorites. Chondrules of typical sizes from 0.1 to 1 mm are ubiquitous in primitive meteorites and likely represent the primary building blocks of asteroids. Chondrule-sized particles are nevertheless tightly coupled to the gas via friction and are therefore hard to concentrate in large amounts in the turbulent gas. We review recent progress on understanding the incorporation of chondrules into the asteroids, including layered accretion models where chondrules are accreted onto asteroids over millions of years. We highlight in the end ten unsolved questions in asteroid formation where we expect that progress will be made over the next decade.Comment: Chapter to appear in the book ASTEROIDS IV, (University of Arizona Press) Space Science Series, edited by P. Michel, F. DeMeo and W. Bottk

Natural Gas Landowner Coalitions in New York State: Emerging Benefits of Collective Natural Resource Management

Thousands of rural landowners in New York State have joined together to form grassroots organizations aimed at collectively bargaining with natural gas companies. The leverage afforded by acting collectively allows these landowner coalitions to potentially influence the economic, environmental, and community impacts of gas development across hundreds of thousands of acres. In-depth interviews with coalition leaders conducted for this article reveal the scope, motivations, and benefits of membership in these groups. Our work examines these elements using multiple frameworks for understanding collective natural resource management. The coalitions are primarily concerned with the advancement of private member benefits, while public benefits of the collective action are poised to accrue indirectly. Group leaders are also contemplating how to use their leverage to secure direct benefits for the wider community – actions that may give communities a modicum of local control over gas development

Tailoring Extension Efforts for Promotion of Diversified Crop Rotation Systems

We conducted a survey in the northern Great Plains to better understand farmer-preferred learning sources and formats, influential factors, and challenges related to adoption of diversified crop rotation systems. University Extension was ranked as the second most preferred learning source, lagging only behind other farmers. Most farmers listed short seminars and Extension fact sheets as their most preferred learning formats, and most viewed crop productivity and soil health as the most influential factors for new-practice adoption. Our findings can help Extension educators better facilitate future adoption of diversified cropping systems as a conservation practice

Natural Gas Development: Views of New York and Pennsylvania Residents in the Marcellus Shale Region

CaRDI Research & Policy Brief Issue 39; Community & Energy: Nonrenewable Energy Production and Developmen

The complexity of pluralistic ignorance in Republican climate change policy support in the United States

Most Americans fail to recognize widespread public support for climate change action. Here we investigate how this phenomenon differs for Republican supporters versus opponents of several climate change policies. Surveying a representative sample of Republican voters (N = 1000), we find that misperception of in-group support for climate action is primarily restricted to Republicans already opposed to action. Specifically, those in the minority (i.e., Republicans opposed to climate action) were more likely to erroneously perceive other Republicans as holding views on climate change policy similar to their own. While Republican supporters recognize that most Republicans support climate change policy, they may be discouraged from expressing their support due to an information environment disproportionately portraying Republicans as opposed to climate change action

Relevant Information Sources in the Vast and Complex Manure Nutrient Management Network

To understand and delineate pathways for effective information transfer among professional audiences in manure nutrient management, we deployed a survey, taken by 964 professionals, addressing workforce demographics, tasks performed, and information source relevance. Findings indicate that education of industry and the public is a widespread effort among the multiple organizations represented. The average relevance of different types of information sources was consistent across various organization types. Compared to mass media sources, information sources that were technical and individual- or group-oriented in nature were more relevant to respondents representing all organization types and levels of knowledge. Opportunities exist for translation of the findings presented to other networks of entities working toward common objectives

Winds of Change – Predicting Water-Based Recreationists\u27 Support and Opposition for Offshore Wind Energy Development in the Great Lakes

This study examined the factors influencing water-based recreationists\u27 perceptions of support and opposition towards off-shore wind energy development (OWD) on Lake Erie. Much of the proposed or future Lake Erie OWD infrastructure may either be within or adjacent to public lands, waters, and protected areas, raising concerns about the potential environmental and social impacts upon recreation stakeholders. The limited body of OWD research within the United States has suggested there are numerous factors that may influence overall perceptions of support and opposition such as political orientation and beliefs in climate change. Moreover, recent research has proposed that the perceived recreation impact of OWD may be the most important predictor of support and opposition. This study confirmed this premise and found the perceived recreation impact of OWD to be the strongest predictor of support. Results of a multiple linear regression suggested that political orientation (β = 0.135), beliefs in the anthropogenic causation of climate change (β = 0.207), beliefs in the occurrence of climate change (β = 0.213), and the perceived recreation impact of OWD among water-based recreationists (β = 0.439) were significant predictors of support for OWD on Lake Erie (R2 = 0.46). Study findings corroborated previous research which suggested that regional climate change beliefs and political attitudes may influence support for OWD. From a policy and management standpoint, study results highlight the importance of assessing and communicating recreation experience and use impacts when planning, developing, and managing OWD and related decisions in the United States

Residents\u27 Perceptions of Community and Environmental Impacts From Development of Natural Gas in the Marcellus Shale: A Comparison of Pennsylvania and New York Cases

Communities experiencing rapid growth due to energy development (‘boomtowns’) have reported positive and negative impacts on community and individual well-being. The perceptions of impacts vary according to stage of energy development as well as experience with extractive industries. Development of the Marcellus Shale provides an opportunity to examine these impacts over time and across geographic and historical contexts. This paper describes case study research in Pennsylvania and New York to document preliminary impacts of development occurring there. Cases vary by level of development and previous extractive history. The study finds that, in areas with low population density, higher levels of development lead to a broader awareness of natural gas impacts, both positive and negative. Participants draw from the regional history of extraction to express environmental concern despite direct, local experience. Our findings suggest the need to track these perceptions during development, and as individuals and communities react and adapt to the impacts