It is known that large asteroids and comets can collide with the Earth with severe consequences. Although the chances of a collision in a person's lifetime are small, collisions are a random process and could occur at any time. This book collects the latest thoughts and ideas of scientists concerned with mitigating the threat of hazardous asteroids and comets. It reviews current knowledge of the population of potential colliders, including their numbers, locations, orbits, and how warning times might be improved. The structural properties and composition of their interiors and surfaces are reviewed, and their orbital response to the application of pulses of energy is discussed. Difficulties of operating in space near, or on the surface of, very low mass objects are examined. The book concludes with a discussion of the problems faced in communicating the nature of the impact hazard to the public.

This volume is a compilation of the research presented at the International Asteroid Day workshop which was celebrated at Barcelona on June 30th, 2015. The proceedings discuss the beginning of a new era in the study and exploration of the solar system’s minor bodies. International Asteroid Day commemorates the Tunguska event of June 30th, 1908. The workshop’s goal was to promote the importance of dealing proactively with impact hazards from space. Multidisciplinary experts contributed to this discussion by describing the nature of comets and asteroids along with their offspring, meteoroids. New missions to return material samples of asteroids back to Earth such as Osiris-REx and Hayabusa 2, as well as projects like AIM and DART which will test impact deflection techniques for Potentially Hazardous Asteroids encounters were also covered. The proceedings include both an outreach level to popularize impact hazards and a scientific character which covers the latest knowledge on these topics, as well as offering proposals of promising new techniques that will help gain new insights of the properties of these challenging bodies by studying meteoroids and meteorites. Asteroids, comets, meteoroids and meteorites are introduced with descriptions of their nature, origin, and solar system pathways.

Planetary defense from near-Earth objects such as asteroids is a far more nuanced and challenging topic than it might seem. Each day, technology is making it easier to detect asteroid impact threats in advance, but at present, there is still no easy way to design and implement any form of global defense. This book examines how various asteroid deflection methods can change global political affairs. The authors believe that the final policy for potential Earth impacts should be based on practical engineering solutions and innovative architectural structures, while at the same time reflecting the most recent political science contributions in ethical security studies and security cosmopolitanism. Their focus is not limited to effective engineering solutions, but rather extends to how such proposals resonate in possible political structures of the future. Planetary defense cannot be achieved with technology alone; the chapters in this volume highlight the issues that arise when space science and technology intersect with political science. This complex interdisciplinary project not only demands global participation and collaboration, but also proposes the way we can achieve it. The authors explore various concepts of governance and their far-reaching implications for planetary defense and vice versa—how scientific progress in Solar System observations and asteroid collision engineering influence political science and put pressure on the international legal framework. The text is intentionally written for a diverse scholarly and diplomatic audience in a style accessible to non-specialists and practitioners and can be read by those across diverse disciplinary backgrounds.

Leading specialists in various disciplines were first invited to a multidisciplinary workshop funded by ICSU on the topic to gain a better appreciation and perspective on the subject of comet/asteroid impacts as viewed by different disciplines. This volume provides a necessary link between various disciplines and comet/asteroid impacts.

The United States spends approximately $4 million each year searching for near-Earth objects (NEOs). The objective is to detect those that may collide with Earth. The majority of this funding supports the operation of several observatories that scan the sky searching for NEOs. This, however, is insufficient in detecting the majority of NEOs that may present a tangible threat to humanity. A significantly smaller amount of funding supports ways to protect the Earth from such a potential collision or "mitigation." In 2005, a Congressional mandate called for NASA to detect 90 percent of NEOs with diameters of 140 meters of greater by 2020. Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies identifies the need for detection of objects as small as 30 to 50 meters as these can be highly destructive. The book explores four main types of mitigation including civil defense, "slow push" or "pull" methods, kinetic impactors and nuclear explosions. It also asserts that responding effectively to hazards posed by NEOs requires national and international cooperation. Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies is a useful guide for scientists, astronomers, policy makers and engineers.

This volume considers the role comets may have played in the origins and evolution of life. This is the only book dealing in depth with this subject. It is particularly relevant in light of recent investigations of Halley's comet, of new insights into organic synthesis in meteorites and comets, and of new results of numerical simulations of cometary orbits and impacts on Earth. The book is intended as a comprehensive review of current research.

"More than forty chapters detail our current astronomical, compositional, geological, and geophysical knowledge of asteroids, as well as their unique physical processes and interrelationships with comets and meteorites"--Provided by publisher.

Proceedings of IAU Symposium 229 on minor bodies of the solar system, for researchers and graduate students of planetary sciences.

PART 1? WHY RISK ASSESSMENT -- Chapter 1? Understanding Risk Assessement -- 1.1The Target Risks -- 1.2The Quantitative Definition of Risk -- 1.3The Meaning of Quantification -- 1.4Form of the Results of a Quantitative Risk Assessment -- 1.5References -- Chapter 2? Analytical Foundations of Quantitative Risk Assessment -- 2.1Quantitative Definition of Risk -- 2.2The Scenario Approach to Quantitative Risk Assessment -- 2.3Interpretation of Probability and Likelihood -- 2.4Quantification of the Scenarios -- 2.5Assembling the Results -- 2.6References -- Chapter 3? The Rational Management of Catastrophic Risks -- 3.1Benefits of Quantitative Risk Assessment -- 3.2The Role of the Case Studies -- 3.3Comparing Quantitative Risks Using the Case Studies -- 3.4Observations from the Case Studies -- 3.5Insights from Comparing Results -- 3.6Where Do We Go from Here? -- References -- PART 2? Risk Assessment Case Studies -- Chapter 3? Risk of a Catastrophic Hurricane in -- 3.1Summary of the Risk Assess ...