Understanding The Interiors Of Vesta And Ceres Through Their Interactions With The Solar Wind

The Gamma Ray and Neutron Detector (GRaND) onboard the Dawn spacecraft is sensitive to energetic protons, energetic electrons, and strong magnetic fields. This allows us to probe the local space environment while Dawn was in orbit about Vesta and Ceres. Understanding how these planets interact with the solar wind provides information about properties of the planetary surface and its interior. At Vesta, we searched for evidence of a past dynamo by attempting to indirectly detect remanent crustal fields. We scanned the GRaND data for solar wind electrons reflected by local crustal fields and by sensing effects of the magnetic field on the BGO spectrum. We did not find any evidence for reflected electrons or shifts in the BGO spectrum caused by magnetism associated with Vesta. Based on the sensitivity of the instrument, we conclude the upper bound for the magnetic dipole moment to be 6*10^8 Tm^3. At Ceres, we have interpreted sudden bursts of energetic electrons detected by GRaND to be an electron foreshock produced by reflection and acceleration of solar wind electrons encountering a bow shock surface. This phenomenon occurred on a timescale of ~10 days, suggesting the bow shock to be a transient feature, most likely produced by a temporary exosphere. We show that a temporary exosphere at Ceres can be produced by solar energetic particle events which are capable of sputtering water ice from the surface.

The NASA Dawn mission, launched in 2007, aimed to visit two of the most massive protoplanets of the main asteroid belt: Vesta and Ceres. The aim was to further our understanding of the earliest days of the Solar System, and compare the two bodies to better understand their formation and evolution. This book summarises state-of-the-art results from the mission, and discusses the implications for our understanding not only of the asteroid belt but the entire Solar System. It comprises of three parts: Part 1 provides an overview of the main belt asteroids and provides an introduction to the Dawn mission; Part 2 presents key findings from the mission; and Part 3 discusses how these findings provide insights into the formation and evolution of the Solar System. This is a definitive reference for academic researchers and professionals of planetary science, asteroid science and space exploration.

Explore the development and state-of-the-art in deep space exploration using radio science techniques In Radio Science Techniques for Deep Space Exploration, accomplished NASA/JPL researcher and manager Sami Asmar delivers a multi-disciplinary exploration of the science, technology, engineering, mission operations, and signal processing relevant to deep space radio science. The book discusses basic principles before moving on to more advanced topics that include a wide variety of graphical illustrations and useful references to publications by experts in their respective fields. Complete explanations of changes in the characteristics of electromagnetic waves and the instrumentation and technology used in scientific experiments are examined. Radio Science Techniques for Deep Space Exploration offers answers to the question of how to explore the solar system with radio links and better understand the interior structures, atmospheres, rings, and surfaces of other planets. The author also includes: Thorough introductions to radio science techniques and systems needed to investigate planetary atmospheres, rings, and surfaces Comprehensive explorations of planetary gravity and interior structures, as well as relativistic and solar studies Practical discussions of instrumentation, technologies, and future directions in radio science techniques Perfect for students and professors of physics, astronomy, planetary science, aerospace engineering, and communications engineering, Radio Science Techniques for Deep Space Exploration will also earn a place in the libraries of engineers and scientists in the aerospace industry.

Thanks to NASA's Dawn mission, the last half-decade has witnessed a significant advance in our understanding of Ceres. The largest object between the orbits of Mars and Jupiter, Ceres is the most water-rich body in the inner solar system after Earth which shows evidence of brine-driven activity in its recent history, and even possibly at the present. The potential existence of a subsurface ocean or regional seas in Ceres and its salt- and organic-rich composition underscore its astro-biological significance. After signaling the discovery of the asteroid belt more than two centuries ago, Ceres once again reveals new insights for us to understand the formation, evolution, and habitability of this large icy body in our solar system. This book reviews the current state of knowledge about Ceres after the extensive scientific exploration by the Dawn mission. Starting from the introduction of the discovery of Ceres and what we know about this enigmatic world before Dawn's arrival, each chapter focuses on one aspect of Ceres, including its surface composition, its geology, the role of water ice in shaping Ceres's surface, its interior structure, and expressions of cryovolcanic or brine activity at the surface. Following this framework, the book addresses the astro-biological significance of Ceres. The last chapter summarizes the new questions opened by the Dawn mission and the next step to exploring the dwarf planet closest to Earth.

Environmental sociology tends to be dominated by macrosociological theories, to the point that microsociological perspectives have been neglected and ignored. This collection of original work is the first book dedicated to demonstrating the utility of microsociological perspectives for investigating environmental issues. From symbolic interactionism to actor–network theory, from dramaturgy to conversation analysis, from practice theory to animism, a variety of microsociological perspectives are not only drawn upon but creatively applied and developed, making this collection not only a contribution to environmental sociology, but to microsociological theory as well. The authors address such topics as the treatment of waste, human–animal relations, science and industry partnerships, environmental social movements, identities, and lifestyles, eco-tourism, the framing of land, water, and natural resources, and even human conceptions of outer space. Bringing together diverse scholars, perspectives, and topics, Microsociological Perspectives for Environmental Sociology opens the field up to new approaches and initiates much needed dialogue between environmental sociologists and microsociologists. It will appeal not only to sociologists, but to environmental scholars across the social sciences interested in enriching their theoretical repertoire in studying the social aspects of the environment.

When we look at a starry night sky, we are looking out through vast invisible expanses of our own Solar System. The planets, appearing as bright specks, have been revealed as worlds by space missions. However, the invisible spaces between them are equally interesting. Unseen forces, such as the effect of gravity, spiraling magnetic fields, and subatomic particles, originate from the Sun. Celestial bodies too small to see form unexpected patterns, while atoms and nuclei are hidden even if in our own bodies. Weaving the history of discovery with clear explanations, Invisible Solar System pulls back the cloak of invisibility under which myriad aspects of the local region of space are connected. Features: • Gravity, originally seen as an invisible force, is now revealed as a curvature of spacetime, and, even in its simple form, enables amazing patterns to form • The smallest particles have other structures that enable them to interact, powering the present Solar System while also giving clues to nuclear events past and present • Long-range forces of electricity and magnetism connect the Sun and planets, dominating the hot plasma gas of space while protecting us from cosmic rays via multiple layers of magnetic shields Martin Connors is a Professor of Astronomy, Mathematics, and Physics at Canada’s dominant distance education institution, Athabasca University. He is also affiliated with the planetary science group at Western University in London, Canada. He has authored numerous courses and scientific articles. His wide-ranging research has extended from the history of astronomy, through asteroids and their impact craters, to auroras and their magnetic effects. He has been a visiting professor at UCLA and at Nagoya University in Japan. When not doing scientific work, he reads about history, practices foreign languages, and blends photography with travel when possible.

Earth’s Oldest Rocks provides a comprehensive overview of all aspects of early Earth, from planetary accretion through to development of protocratons with depleted lithospheric keels by c. 3.2 Ga, in a series of papers written by over 50 of the world's leading experts. The book is divided into two chapters on early Earth history, ten chapters on the geology of specific cratons, and two chapters on early Earth analogues and the tectonic framework of early Earth. Individual contributions address topics that range from planetary accretion, a review of Earth meteorites, significance and composition of Hadean protocrust, composition of Archaean mantle and deep crust, all aspects of the geology of Paleoarchean cratons, composition of Archean oceans and hydrothermal environments, evidence and geological settings of early life, early Earth analogues from Venus and New Zealand, and a tectonic framework for early Earth. * Contains comprehensive reviews of areas of ancient lithosphere on Earth, of planetary accretion processes, and of meteorites* Focuses on specific aspects of early Earth, including oldest putative life forms, evidence of the composition of the ancient atmosphere-hydrosphere, and the oldest evidence for subduction-accretion* Presents an overview of geological processes and model of the tectonic framework on early Earth

In spring 2011 the National Academies of Sciences, Engineering, and Medicine produced a report outlining the next decade in planetary sciences. That report, titled Vision and Voyages for Planetary Science in the Decade 2013-2022, and popularly referred to as the "decadal survey," has provided high-level prioritization and guidance for NASA's Planetary Science Division. Other considerations, such as budget realities, congressional language in authorization and appropriations bills, administration requirements, and cross-division and cross-directorate requirements (notably in retiring risk or providing needed information for the human program) are also necessary inputs to how NASA develops its planetary science program. In 2016 NASA asked the National Academies to undertake a study assessing NASA's progress at meeting the objectives of the decadal survey. After the study was underway, Congress passed the National Aeronautics and Space Administration Transition Authorization Act of 2017 which called for NASA to engage the National Academies in a review of NASA's Mars Exploration Program. NASA and the Academies agreed to incorporate that review into the midterm study. That study has produced this report, which serves as a midterm assessment and provides guidance on achieving the goals in the remaining years covered by the decadal survey as well as preparing for the next decadal survey, currently scheduled to begin in 2020.

Contains 250 questions and answers about astronomy, particular for the amateur astronomer.