Download or read book Hyper Velocity Impacts on Rubble Pile Asteroids written by Jakob Deller and published by Springer. This book was released on 2016-12-01 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis presents a tool to create rubble pile asteroid simulants for use in numerical impact experiments, and provides evidence that the asteroid disruption threshold and the resultant fragment size distribution are sensitive to the distribution of internal voids. This thesis represents an important step towards a deeper understanding of fragmentation processes in the asteroid belt, and provides a tool to infer the interior structure of rubble pile asteroids. Most small asteroids are 'rubble piles' – re-accumulated fragments of debris from earlier disruptive collisions. The study of fragmentation processes for rubble pile asteroids plays an essential part in understanding their collisional evolution. An important unanswered question is “what is the distribution of void space inside rubble pile asteroids?” As a result from this thesis, numerical impact experiments can now be used to link surface features to the internal structure and therefore help to answer this question. Applying this model to asteroid Šteins, which was imaged from close range by the Rosetta spacecraft, a large hill-like structure is shown to be most likely primordial, while a catena of pits can be interpreted as evidence for the existence of fracturing of pre-existing internal voids.

Download or read book Ricochets and Stranding Boulders on Rubble Pile Asteroids written by Esteban Miquel Wright and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Many asteroids are 'rubble piles', conglomerations of weakly gravitationally bounded material. Impacts and spin-out events can produce a population of gravitational bound objects in orbit that can impact the surface at low velocity and a distribution of impact angles. For the first study, we present low velocity, oblique impacts of spherical projectiles into fine sand. With high speed video and fluorescent markers on the projectiles we track projectile trajectory and spin during impact. We delineate impact velocities and angles where projectiles ricochet, roll-out from their impact crater, or stop within their impact crater. We estimate constraints on projectile radius, velocity, and impact angle that would allow projectiles on asteroids to ricochet or roll away from initial impact site. The critical grazing impact angle dividing ricochets from roll-outs increases with impact velocity and is matched by an empirical model that balances a lift force against gravity during the rebound phase. The required friction coefficient during the penetration phase is 4-5 times lower than for sand suggesting it is fluidized near the projectile surface during penetration. In a second study, we compared ricocheting impactors with the same impact velocity and angle into granular media with different mean grain size. The ratio of projectile diameter to mean grain length ranges from 4 in our coarsest medium to 50 in our finest sand. We measure coefficients of restitutions, the ratio of pre- to post-impact horizontal and vertical velocity components, and the angle of deflection caused by the impact in the horizontal plane. Coefficients of restitution are sensitive to mean grain size with the horizontal coefficient about twice as large for our coarsest gravel compared to our finest sand. This implies that coefficients for hydro-static-like, drag-like and lift-like forces, used in empirical force laws are sensitive to mean grain size, with the lift coefficient being the most sensitive. The deflection angles are largest in the coarser media and their size approximately depends on grain size to the 3/2 power. The dependence of impact dynamics on substrate size distribution should be considered in future models for impacts on granular asteroid surfaces. For the third study, we consider how a subsurface seismic pulse affects the surface of an asteroid distant from the impact site. Using dry polydisperse gravel mixture, we film and track the ejecta launched by a single upward propagating pressure pulse. We find ejecta trajectories are independent of particle size, and collisions primarily take place upon landing, where smaller particles are scattered off larger particles, a process dubbed 'ballistic sorting'. A single strong pulse can strand previously buried boulders on the surface and is an additional mechanism for large boulders present on the surface of rubble asteroids such as 162173 Ryugu, 101955 Bennu and 25143 Itokawa"--Pages viii-ix.

Download or read book Proceedings of the Workshop for Hypervelocity Impacts in Space written by J. A. M. McDonnell and published by . This book was released on 1992 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Asteroids IV written by Patrick Michel and published by University of Arizona Press. This book was released on 2015-12-31 with total page 946 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade, asteroids have come to the forefront of planetary science. Scientists across broad disciplines are increasingly recognizing that understanding asteroids is essential to discerning the basic processes of planetary formation, including how their current distribution bespeaks our solar system’s cataclysmic past. For explorers, the nearest asteroids beckon as the most accessible milestones in interplanetary space, offering spaceflight destinations easier to reach than the lunar surface. For futurists, the prospects of asteroids as commercial resources tantalize as a twenty-first-century gold rush, albeit with far greater challenges than faced by nineteenth-century pioneers. For humanity, it is the realization that asteroids matter. It is not a question of if—but when—the next major impact will occur. While the disaster probabilities are thankfully small, fully cataloging and characterizing the potentially hazardous asteroid population remains unfinished business. Asteroids IV sets the latest scientific foundation upon which all these topics and more will be built upon for the future. Nearly 150 international authorities through more than 40 chapters convey the definitive state of the field by detailing our current astronomical, compositional, geological, and geophysical knowledge of asteroids, as well as their unique physical processes and interrelationships with comets and meteorites. Most importantly, this volume outlines the outstanding questions that will focus and drive researchers and students of all ages toward new advances in the coming decade and beyond.

Download or read book Asteroids III written by William Frederick Bottke and published by University of Arizona Press. This book was released on 2002-01-01 with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two hundred years after the first asteroid was discovered, asteroids can no longer be considered mere points of light in the sky. Spacecraft missions, advanced Earth-based observation techniques, and state-of-the-art numerical models are continually revealing the detailed shapes, structures, geological properties, and orbital characteristics of these smaller denizens of our solar system. This volume brings together the latest information obtained by spacecraft combined with astronomical observations and theoretical modeling, to present our best current understanding of asteroids and the clues they reveal for the origin an,d evolution of the solar system. This collective knowledge, prepared by a team of more than one hundred international authorities on asteroids, includes new insights into asteroid-meteorite connections, possible relationships with comets, and the hazards posed by asteroids colliding with Earth. The book's contents include reports on surveys based on remote observation and summaries of physical properties; results of in situ exploration; studies of dynamical, collisional, cosmochemical, and weathering evolutionary processes; and discussions of asteroid families and the relationships between asteroids and other solar system bodies. Two previous Space Science Series volumes have established standards for research into asteroids. Asteroids III carries that tradition forward in a book that will stand as the definitive source on its subject for the next decade.

Download or read book The Solar System Beyond Neptune written by M. Antonietta Barucci and published by University of Arizona Press. This book was released on 2008 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new frontier in our solar system opened with the discovery of the Kuiper Belt and the extensive population of icy bodies orbiting beyond Neptune. Today the study of all of these bodies, collectively referred to as trans-Neptunian objects, reveals them to be frozen time capsules from the earliest epochs of solar system formation. This new volume in the Space Science Series, with one hundred contributing authors, offers the most detailed and up-to-date picture of our solar systemÕs farthest frontier. Our understanding of trans-Neptunian objects is rapidly evolving and currently constitutes one of the most active research fields in planetary sciences. The Solar System Beyond Neptune brings the reader to the forefront of our current understanding and points the way to further advancement in the field, making it an indispensable resource for researchers and students in planetary science.

Download or read book Development of a Numerical Simulation Method for Rocky Body Impacts and Theoretical Analysis of Asteroidal Shapes written by Keisuke Sugiura and published by Springer Nature. This book was released on 2020-03-17 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes numerical simulations of collisions between asteroids, based on a unique numerical code developed by the author. The code accurately solves the elastic dynamic equations and describes the effects of fracture and friction, which makes it possible to investigate the shapes of impact outcomes produced by asteroid collisions and subsequent gravitational accumulation of fragments. The author parallelizes the code with high parallelization efficiency; accordingly, it can be used to conduct high-resolution simulations with the aid of supercomputers and clarify the shapes of small remnants produced through the catastrophic destruction of asteroids. The author demonstrates that flat asteroids can only be produced by impacts involving objects with similar mass and low velocity, which suggests that the flat asteroids in our solar system were created in the planet formation era and have kept their shapes until today. The author also shows that asteroid collisions under certain conditions can produce the extremely elongated shape of an interstellar minor body, 1I/‘Oumuamua. In brief, the book offers a comprehensive investigation of asteroid impacts and shapes, making it a uniquely valuable resource.

Download or read book Mitigation of Hazardous Comets and Asteroids written by M. J. S. Belton and published by Cambridge University Press. This book was released on 2004-09-06 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Physics of the Earth and the Solar System written by B. Bertotti and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews: ".....The book is a very good balance between theory and applications, of analysis and synthesis, keeping always the focus on the comprehension of the physics ruling our planetary system. In summary, this represents both an excellent textbook for students and a fundamental reference, and encyclopedic summary current knowledge, for researchers in the Solar System field." (Alessandro Rossi, Celestial Mechanics and Dynamical Astronomy, 2005)

Download or read book Role Of Permanent Monitoring Panels the Proceedings Of The International Seminar On Nuclear War And Planetary Emergen written by Klaus Goebel and published by World Scientific. This book was released on 1999-07-13 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the opening session the Chairman of the Seminar underlined the important role of the permanent monitoring panels with respect to the 15 planetary emergencies. A special session of the Seminar was devoted to reporting on the activity of these panels. Short papers, abstracts and transparencies in the opening session introduced the subjects of the contributions: 'Climatology and El Nino' (Nadia Pinardi, Neville Nicholls, Congbin Fu, Akimasa Sumi, William Sprigg and Llowell Wood) and 'Desertification' (Douglas Johnson, Xinmin Liu, Lennart Olsson and Norman Rosenberg). Contributions on 'Medicine & Biotechnologies' were presented by Paul Brown, Robert Will, Benardino Ghetti and Guy de The. The Theme 'Defence Against Cosmic Objects' was covered by Walter Huebner, John Remo and William Bottke; 'Water and Pollution' by Herman Bouwer, Gennady Palshin, David Rice and Paolo Ricci; and problems centered upon 'Food' by Carlo Lerici and Silvia Franceschi, 'Proliferation and Weapons of Mass Destruction' was discussed by Henning Wegener, Andrei Piontkovski, Reiner Huber, Tony Mason, Willis Stanley, Gregory Canavan and Povl Olgaard; 'Limits of Development' by Hilmar Schubert and Leonardas Kairiukstis; and 'Energy' by Stanislav Subbotin, Andrei Gagarinski and Eugeni Velikhov. T D Lee closed the Seminar by emphasizing the link between basic science and planetary emergencies.

Download or read book Meteorites and the Early Solar System II written by Dante S. Lauretta and published by University of Arizona Press. This book was released on 2006-07-01 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt: They range in size from microscopic particles to masses of many tons. The geologic diversity of asteroids and other rocky bodies of the solar system are displayed in the enormous variety of textures and mineralogies observed in meteorites. The composition, chemistry, and mineralogy of primitive meteorites collectively provide evidence for a wide variety of chemical and physical processes. This book synthesizes our current understanding of the early solar system, summarizing information about processes that occurred before its formation. It will be valuable as a textbook for graduate education in planetary science and as a reference for meteoriticists and researchers in allied fields worldwide.

Download or read book Flugzeug Z 43 dreiundvierzig Nutzung Betrieb und Steuertechnik written by and published by . This book was released on 1976 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book From Dust to Terrestrial Planets written by Willy Benz and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: The workshop "From Dust to Terrestrial Planets" was initiated by a working group of planetary scientists invited to ISSI by Johannes Geiss in November 1997. The group split to focus on three topics, one of which was the history of the early solar system, including the formation of the terrestrial planets in the inner solar system. Willy Benz, Gunter Lugmair, and Frank Podosek were invited to convene planetary scientists, astrophysicists, and cosmochemists to synthesize the current knowledge on the origin and evolution of our inner planetary system. The convenors raised the interest of scientists from all over the world in the detailed assessment of the available astronomical, chronological, geochemical and dynamical constraints of the first period of inner solar system evolution. In partic ular, this included appraisal of the newest results from astronomical observations by the Hubble Space Telescope, the Infrared Space Observatory, and other space and ground-based facilities of solar-like systems and nebular disks, possibly repre senting early stages of the solar accretion disk and planet formation. At the same time, the current models of the origin, evolution, transport, and accretion processes of circum stellar disks were presented. This included the new insights provided by the recent discovery of extrasolar giant planets, which were considered insofar as they are relevant to the overall dynamics of the inner part of the solar system.

Download or read book Hazards of Hypervelocity Impacts on Spacecraft written by Shu T. Lai and published by . This book was released on 2002 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypervelocity impacts by space particles, such as meteoroids and debris, pose hazards to spacecraft. The limits of velocity of meteoroid and debris are derived. Characteristic properties of hypervelocity impacts are momentum transfer, penetration, plasma production, localization, and suddenness. Using McDonnell's empirical formulas derived from laboratory experiments, impact penetrations and plasma production rates in the space environment are calculated. When the critical temperature theorem for Maxwellian space plasmas is used, the energy of the plasma generated is shown to be too low to induce any significant spacecraft charging. The plasma generated, however, can induce a transient, sustained or avalanche discharge between differentially charged surfaces. The discharge current depends not only on the plasma density generated but also on the neutral gas released on impact. A scenario of impact induced hazard following days of passage of a high-energy plasma cloud, such as a coronal mass ejection cloud, is discussed. Some mitigation methods are discussed. Finally, we discuss whether electrons can be accelerated to high energies in a meteor trail.

Download or read book High velocity Impact Phenomena written by A. J. Cable and published by . This book was released on 1970 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Small Bodies in Planetary Systems written by Ingrid Mann and published by Springer. This book was released on 2009-03-01 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: The small bodies in planetary systems are indicative of the material evo- tion, the dynamical evolution, and the presence of planets in a system. Recent astronomicalresearch,spaceresearch,laboratoryresearch,andnumericals- ulationsbroughtawealthofnewandexciting?ndingsonextra-solarplanetary systems and on asteroids, comets, meteoroids, dust, and trans-Neptunian - jects in the solar system. Progress in astronomical instrumentation led to the discovery and investigation of small bodies in the outer solar system and to observations of cosmic dust in debris disks of extra-solar planetary systems. Space research allowed for close studies of some of the small solar system bodies from spacecraft. This lecture series is intended as an introduction to the latest research results and to the key issues of future research. The ch- ters are mainly based on lectures given during a recent research school and on research activities within the 21st Century COE Program “Origin and Evolution of Planetary Systems” at Kobe University, Japan. In Chap. 1, Taku Takeuchi discusses the evolution of gas and dust from protoplanetary disks to planetary disks. Using a simple model, he studies v- cous evolution and photoevaporation as possible mechanisms of gas dispersal. He further considers how the dust grows into planetesimals. Motion of dust particles induced by gas drag is described, and then using a simple analytic model, the dust growth timescale is discussed.

Download or read book Hypervelocity Impact Physics written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-25 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: All large spacecraft are susceptible to impacts by meteoroids and orbiting space debris. These impacts occur at extremely high speed and can damage flight-critical systems, which can in turn lead to a catastrophic failure of the spacecraft. Therefore, the design of a spacecraft for a long-duration mission must take into account the possibility of such impacts and their effects on the spacecraft structure and on all of its exposed subsystems components. The work performed under the contract consisted of applied research on the effects of meteoroid/space debris impacts on candidate materials, design configurations, and support mechanisms of long term space vehicles. Hypervelocity impact mechanics was used to analyze the damage that occurs when a space vehicle is impacted by a micrometeoroid or a space debris particle. An impact analysis of over 500 test specimens was performed to generate by a hypervelocity impact damage database. Schonberg, William P. and Bean, Alan J. and Darzi, Kent Unspecified Center NASA-CR-4343, NAS 1.26:4343 NAS8-36955...