Numerical and Probabilistic Analysis of Asteroid and Comet Impact Hazard Mitigation

Numerical and Probabilistic Analysis of Asteroid and Comet Impact Hazard Mitigation

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Published: 2010

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The possibility of asteroid and comet impacts on Earth has received significant recent media and scientific attention. Still, there are many outstanding questions about the correct response once a potentially hazardous object (PHO) is found. Nuclear munitions are often suggested as a deflection mechanism because they have a high internal energy per unit launch mass. However, major uncertainties remain about the use of nuclear munitions for hazard mitigation. There are large uncertainties in a PHO's physical response to a strong deflection or dispersion impulse like that delivered by nuclear munitions. Objects smaller than 100 m may be solid, and objects at all sizes may be 'rubble piles' with large porosities and little strength. Objects with these different properties would respond very differently, so the effects of object properties must be accounted for. Recent ground-based observations and missions to asteroids and comets have improved the planetary science community's understanding of these objects. Computational power and simulation capabilities have improved such that it is possible to numerically model the hazard mitigation problem from first principles. Before we know that explosive yield Y at height h or depth -h from the target surface will produce a momentum change in or dispersion of a PHO, we must quantify energy deposition into the system of particles that make up the PHO. Here we present the initial results of a parameter study in which we model the efficiency of energy deposition from a stand-off nuclear burst onto targets made of PHO constituent materials.


Hazards Due to Comets and Asteroids

Hazards Due to Comets and Asteroids

Author: Tom Gehrels

Publisher: University of Arizona Press

Published: 2021-11-30

Total Pages: 1317

ISBN-13: 0816547416

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In 1993, the U.S. Department of Defense declassified information dealing with frequent explosions in the upper atmosphere caused by meteoric impact. It is estimated that impacts have occurred of a magnitude equivalent to the atomic bomb detonated at Hiroshima. Not all such space voyagers meet their end in the atmosphere, however; huge craters attest to the bombardment of earth over millions of years, and a major impact may have resulted in the extinction of dinosaurs. An impact in Siberia near the beginning of this century proves that such events are not confined to geologic time. Hazards Due to Comets and Asteroids marks a significant step in the attempt to come to grips with the threats posed by such phenomena. It brings together more than one hundred scientists from around the world, who draw on observational and theoretical research to focus on the technical problems related to all aspects of dealing with these hazards: searching for and identifying hazardous comets and asteroids; describing their statistics and characteristics; intercepting and altering the orbits of dangerous objects; and applying existent technologies—rocket boosters, rendezvous and soft-landing techniques, instrumentation—to such missions. The book considers defensive options for diverting or disrupting an approaching body, including solar sails, kinetic-energy impacts, nuclear explosives, robotic mass drivers, and various propulsion systems. A cataclysmic impact posing a threat to life on Earth is a possibility that tomorrow's technology is capable of averting. This book examines in depth the reality of the threat and proposes practical measures that can be initiated now should we ever need to deal with it.


Comet/Asteroid Impacts and Human Society

Comet/Asteroid Impacts and Human Society

Author: Peter T. Bobrowsky

Publisher: Springer Science & Business Media

Published: 2007-06-10

Total Pages: 549

ISBN-13: 3540327118

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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.


Looking Before We Leap

Looking Before We Leap

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Published: 2010

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There are many outstanding questions about the correct response to an asteroid or comet impact threat on Earth. Nuclear munitions are currently thought to be the most efficient method of delivering an impact-preventing impulse to a potentially hazardous object (PHO). However, there are major uncertainties about the response of PHOs to a nuclear burst, and the most appropriate ways to use nuclear munitions for hazard mitigation.


Planning Ahead for Asteroid and Comet Hazard Mitigation, Phase 1

Planning Ahead for Asteroid and Comet Hazard Mitigation, Phase 1

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Published: 2009

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The mitigation of impact hazards resulting from Earth-approaching asteroids and comets has received much attention in the popular press. However, many questions remain about the near-term and long-term, feasibility and appropriate application of all proposed methods. Recent and ongoing ground- and space-based observations of small solar-system body composition and dynamics have revolutionized our understanding of these bodies (e.g., Ryan (2000), Fujiwara et al. (2006), and Jedicke et al. (2006)). Ongoing increases in computing power and algorithm sophistication make it possible to calculate the response of these inhomogeneous objects to proposed mitigation techniques. Here we present the first phase of a comprehensive hazard mitigation planning effort undertaken by Southwest Research Institute and Los Alamos National Laboratory. We begin by reviewing the parameter space of the object's physical and chemical composition and trajectory. We then use the radiation hydrocode RAGE (Gittings et al. 2008), Monte Carlo N-Particle (MCNP) radiation transport (see Clement et al., this conference), and N-body dynamics codes to explore the effects these variations in object properties have on the coupling of energy into the object from a variety of mitigation techniques, including deflection and disruption by nuclear and conventional munitions, and a kinetic impactor.


Asteroid Impact Risk

Asteroid Impact Risk

Author: Josep M. Trigo-Rodríguez

Publisher: Springer Nature

Published: 2022-03-08

Total Pages: 137

ISBN-13: 3030951243

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This book describes the complexity of impact hazards associated with asteroids and comets. The challenge in this regard lies in the heterogeneous nature of these bodies that endanger our planet, which is why we are conducting new experiments to better understand their unique physicochemical properties. Several generations of astronomers have tracked and mapped the orbits of asteroids and comets over the past few centuries, and telescopic surveys have only begun to discover “new” interstellar objects. In addition, cutting-edge software allow our computers to combine the orbits of these elusive bodies to study how they evolve over time and seek to match asteroid complexes as fragments of asteroidal and cometary disruptions. Impact hazards represent one of the greatest threats to the survival of human beings in the medium term. Geological studies show that the stratigraphic record holds clear geological evidence of these rare but transcendental encounters in the history of life on our planet. The study and quantification of past catastrophes can give us clues to face future challenges in the form of potential impacts. Further, it would be illogical to assume that Earth’s interaction with space is limited to major impacts. Every night, Earth is struck by millions of particles, and dozens of meteor showers occur around the globe every year. The study of lake and ocean sediments reveals the magnitude of the continuous contribution of interplanetary matter reaching Earth: roughly 100,000 tons per year. Accordingly, the goal of this book is to underscore the need for society-wide awareness of the dangers associated with asteroid and comet impacts, on the basis of scientific evidence and with no intention of sparking alarmism. After all, we ourselves may only be the fruit of an opportunity given to mammals sixty-five million years ago to evolve after the conflagration that would be the downfall of the dinosaurs. If we have learned to read Earth’s geological history, we should consider ourselves a very fortunate species, and its teachings should equip us to face this problem. The also book emphasizes the role of space missions to gain insights on these bodies, particularly describing the relevance of the DART (NASA) and Hera (ESA) missions to deflect and study Dimorphos, respectively, the small satellite of the Didymos binary asteroid.


The Asteroid Threat

The Asteroid Threat

Author: William E. Burrows

Publisher: Prometheus Books

Published: 2014-06-10

Total Pages: 294

ISBN-13: 1616149140

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Presents a realistic, workable plan for defusing a potentially lethal threat from a rogue asteroid or comet. The explosion of a large meteor over Chelyabinsk, Siberia, in February 2013 is just the latest reminder that planet Earth is vulnerable to damaging and potentially catastrophic collisions with space debris of various kinds. In this informative and forward-looking book, veteran aerospace writer William E. Burrows explains what we can do in the future to avoid far more serious impacts from "Near-Earth Objects" (NEOs), as they are called in the planetary defense community. The good news is that humanity is now equipped with the advanced technology necessary to devise a long-term strategy to protect the planet. Burrows outlines the following key features of an effective planetary defense strategy: * A powerful space surveillance system capable of spotting a serious threat from space at least twenty-five years in advance * A space craft "nudge" that would throw a collision-course asteroid off target long before it poses the threat of imminent impact * A weapons system to be used as a last-ditch method to blast an NEO should all else fail. The author notes the many benefits for world stability and increasing international cooperation resulting from a united worldwide effort to protect the planet. Combining realism with an optimistic can-do attitude, Burrows shows that humanity is capable of overcoming a potentially calamitous situation.


Rain Of Iron And Ice

Rain Of Iron And Ice

Author: John S. Lewis

Publisher: Addison-Wesley Longman

Published: 1996-01-10

Total Pages: 272

ISBN-13:

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John S. Lewis, a planetary scientist, details the recent scientific study which suggests that massive solid bodies from space pose a very real threat to our planet and explores the implications for the future of life on Earth.