Modeling the surface and interior structure of comet nuclei using a multidisciplinary approach

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National Aeronautics and Space Administration, National Technical Information Service, distributor , [Washington, D.C, Springfield, Va
Comets., Galactic nu
StatementC.R. O"Dell, principal investigator, Panos C. Dakoulas, co-invesigator, George M. Pharr, co-investigator.
SeriesNASA contractor report -- NASA CR-188635.
ContributionsDakoulas, Panos., Pharr, George M., United States. National Aeronautics and Space Administration.
The Physical Object
Pagination1 v.
ID Numbers
Open LibraryOL15390891M

Get this from a library. Modeling the surface and interior structure of comet nuclei using a multidisciplinary approach. [C R O'Dell; Panos C Dakoulas; George M Pharr; United States. National Aeronautics and Space Administration.]. Even now, only two comet nuclei (Halley and Bor-relly) have been observed at close distances, where their shapes and sizes can be clearly seen, and none has yet been probed beneath the surface.

Nevertheless, it is the nucleus that, by its structure and composition, determines. from spacecraft platforms close to the comet. For this purpose, a flexible 3-dimensional model of the nucleus and a physical description of the dust acceleration processes in the nucleus neighborhood were developed.

By using realistic shape assumptions for the nucleus we performed a forward modeling of the dust coma structures around the comet. Introduction.

Description Modeling the surface and interior structure of comet nuclei using a multidisciplinary approach FB2

The understanding of the physical structure of comet nuclei has been slow in developing. The surprising variations in the concepts of comets since Newtons day are well documented by Sekanina (a)and need not be repeated here. Estimates of the nuclear density are relatively recent, rising from extremely low values to gm/cm 3 (Whipple, ) based on the icy conglomerate Cited by: The approach was notable for several reasons: it was the first approach of which photographs exist, and the first for which spectctroscopic data were obtained.

Furthermore, the comet made a relatively close approach of AU, making it a spectacular sight. On 18 May the Earth actually passed through the tail of the comet.

comet using the 90 MHz COmet Nucleus Sounding Experiment by Radio Transmission 63 (CONSERT), which will perform a three-dimensional tomographic investigation of the comet’s 64 internal structure.

Above the crystallization front the material is modified due to metamorphic processes, while the interior of the nucleus retains its original composition and structure.

As the comet approaches the Sun, the surface of the nucleus is warmed and the heat wave penetrates downward from the surface and activates metamorphic by: seen in the many comet comae and the fly-bye images of Comet Halley.

A thorough review of the literature on this subject was made and reported upon in this document. (_ASA-CR-IBSO_b) MODELING THE SUqFACF AND NOI INTERIOR SIP, UCT!.I_E OF COMET NUCLEI USING A MULTInlSCIPLINARY APPROACH final Technic_1 Keport, I _ay - 30 S_p. H. Rickman, The nucleus of Comet Halley—Surface structure, mean density, gas and dust production.


Details Modeling the surface and interior structure of comet nuclei using a multidisciplinary approach FB2

Space Res. 9 (3), 59–71 () CrossRef ADS Google ScholarCited by: 5. The Deep Impact observations of low thermal inertia for comet 9P/Tempel 1 are of profound importance for the observations to be made by the Rosetta spacecraft at comet 67P/Churyumov-Gerasimenko. While sub-surface sublimation is necessary to explain the observations, the depth at which this occurs is no more than 2–3 cm and possibly by: 8.

Comet physical characteristics as inherited from their formation stage may be very diverse, both in terms of composition and internal structure. The subsequent evolution of comet nuclei involves.

models – which use surface characteristics as boundary conditions – must be applied to assess the physical processes and internal properties that are indeed inaccessible to observations. The field of modelling comet nuclei made a tremendous leap forward after the detailed observations of comet 1P/Halley by the ESA/Giotto.

Kreutz argued that the comets he studied are possibly fragments of some much larger comet that fell apart at a close approach to the Sun. Sungrazers have.

Abstract. The cryosphere, which comprises a large portion of Earth’s surface, is rapidly changing as a consequence of global climate change.

Ice, snow, and frozen ground in the polar and alpine regions of the planet are known to directly impact atmospheric composition, which for example is observed in the large influence of ice and snow on polar boundary layer : Jennie L. Thomas, Jochen Stutz, Markus M. Frey, Thorsten Bartels-Rausch, Katye Altieri, Foteini Bala.

Incorporating continuum mechanics, quantum mechanics, statistical mechanics, atomistic simulations and multiscale techniques, the book explains many of the key theoretical ideas behind multiscale modeling.

Classical topics are blended with new techniques to demonstrate the connections between different fields and highlight current research trends. applications to the structure of atomic nuclei.

The author systematically develops these models from the elementary level, through an introduction to tensor algebra, to the use of group theory in spectroscopy. The book's extensive and detailed appendix includes a large selection of useful formulae of tensor algebra and by: comet nucleus.

Seen from the perspective of the comet nucleus, the S/C describes increasingly dense trajecto-ries that illuminate its interior from all directions, simi-larly to a 3D tomograph (Figure 1) [6].

Using a combi-nation of lower and higher frequencies, this radar sys-tem enables imaging using techniques from the full. their fundamental, atomistic ultrastructure using atomis-tic modeling techniques.

Structure of collagen and mechanical properties Collagen plays a critical role in many biological tis-sues and materials, including tendon, bone, teeth, carti-lage, and many other materials Collagen and its com-ponents have been studied extensively in the.

The International Space Station (ISS) On-Orbit Assembly, Modeling and Mass Properties Data Book provides a program approved, baseline representation of the ISS as modeled using the March NASA approved Configuration List.

The Systems Engineering, Modeling, and Design Analysis (SEMDA) Laboratory of the. approach is taken to derive the equations of motion which yields compact, closed-form equations of motion.

The derivation uses modeling techniques similar to those used in tile robotics literature (e.g., see [3], [4]). The formulation is relatively general and can be used for a large class of spacecraft.

Buy Simple Models of Complex Nuclei: Shell Model and Interacting Boson Model (Contemporary Concepts in Physics) 1 by Talmi, Igal (ISBN: ) from Amazon's Book Store. Everyday low prices and free delivery on eligible : Igal Talmi. The accuracy of comet orbit computations is limited by uncertain knowledge of the recoil force due to outgassing from the nuclei.

The standard model assumes an exponential dependence of the force on distance from the Sun. This variable force times constants A 1, A 2, and A 3 represents the radial, transverse, and normal components of the net force. ON-ORBIT ASSEMBLY, MODELING, AND MASS PROPERTIES DATA BOOK PREFACE This document was constructed by using the NASA approved Blue Book Revision AB Assembly Matrix that provided by the Strategic Planning, Assembly, Requirements, and Configuration office.

The contents of this document are to be consistent with the tasks and products.

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On modeling micro-structural evolution using a higher order strain gradient continuum theory One approach to modeling the dislocation structures observed is through a back stress formulation, which can be related directly to the strain gradient energy. The present work offers an investigation of constitutive equations for the back stress.

signature of a clear single-particle structure of Λ particle in single-Λ hypernuclei [1, 8, 9, 10]. In particular, single-particle Λ states with orbital angular momen-tum ranging from l = 0 to l = 3 have been clearly identified in medium-heavy 89 Λ Y hypernucleus using the (π Cited by: 1.

ejected from a confined region on the surface of comet 67P/Churyumov-Gerasimenko. The images were obtained in January when the comet was at 2 AU from the Sun out-bound from perihelion.

We measure the acceleration of individual aggregates through a two-hour image series. Approximately 50% of the aggregates are accelerated away from the. Mixed-Symmetry Shell-Model Calculations in Nuclear Physics: Enhancing huge model-space computations of nuclei by using a priori knowledge and intuition Paperback – Aug by Vesselin G.

Gueorguiev (Author)Cited by: 1. In the paper, a mathematical model and a numerical algorithm are proposed for modeling the complex of phenomena which accompany the passage of a friable asteroid-comet body through the Earth’s atmosphere: the material ablation, the dissociation of molecules, and the radiation.

The proposed model is constructed on the basis of the Navier-Stokes equations for viscous heat-conducting gas with Author: V. Shaydurov, G. Shchepanovskaya, M. Yakubovich. MATHEMATICAL MODELING OF FIELD DRIVEN MEAN CURVATURE SURFACES by Derek E.

Moulton Approved: Peter Monk, Ph.D. Chair of the Department of Mathematical Sciences Approved: Tom Apple, Ph.D. Dean of the College of Arts and Sciences Approved: Carolyn A. Thoroughgood, Ph.D. Vice Provost for Research and Graduate Studies.

where n e,s/c is the electron density in the surrounding plasma, e is the elementary charge and the thermal speed, defined as the mean of the magnitude of the velocity in any one dimension, is, where k B is Boltzmann's constant, T e is the electron temperature and m e is the electron mass. A S/C is the total current‐collecting area of the spacecraft, including the solar panels which have Cited by:.

A technical analysis of shape-memory polymers (SMPs) and their composites, particularly in adaptive materials, this volume introduces designs linking SMPs to metals, elastomers, foams, nanoparticles and other materials, as well as the engineering of SMPs directly into parts and active (morphing) components.All these computational challenges need to be addressed simultaneously in FSI modeling of clusters of spacecraft parachutes with modified geometric porosity.

The core numerical technology is the Stabilized Space-Time FSI (SSTFSI) technique, and the contact between the parachutes is handled with the Surface-Edge-Node Contact Tracking (SENCT Cited by: As for the origin of the comet, three-dimensional impact simulations using realistic consti- tutive properties showed results similar to the morphology of the nucleus of 67P (Jutzi and Asphaug,).