scholarly journals Reconnecting groups of space debris to their parent body through proper elements

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alessandra Celletti ◽  
Giuseppe Pucacco ◽  
Tudor Vartolomei
Keyword(s):  
Space Debris ◽  
Parent Body ◽  
Statistical Data Analysis ◽  
Proper Elements ◽  
Dynamical Features ◽  
Break Up ◽  
Osculating Elements ◽  
Original Configuration ◽  
Over Time ◽  
Asteroid Families

AbstractSatellite collisions or fragmentations generate a huge number of space debris; over time, the fragments might get dispersed, making it difficult to associate them to the configuration at break-up. In this work, we present a procedure to back-trace the debris, reconnecting them to their original configuration. To this end, we compute the proper elements, namely dynamical quantities which stay nearly constant over time. While the osculating elements might spread and lose connection with the values at break-up, the proper elements, which have been already successfully used to identify asteroid families, retain the dynamical features of the original configuration. We show the efficacy of the procedure, based on a hierarchical implementation of perturbation theory, by analyzing the following four different case studies associated to satellites that underwent a catastrophic event: Ariane 44lp, Atlas V Centaur, CZ-3, Titan IIIc Transtage. The link between (initial and final) osculating and proper elements is evaluated through tools of statistical data analysis. The results show that proper elements allow one to reconnect the fragments to their parent body.

scholarly journals Numerical mean elements for asteroid orbits

1996 ◽  
Vol 172 ◽  
pp. 165-170 ◽  
Author(s):  
Anne Lemaitre
Keyword(s):  
Body Problem ◽  
Minor Planets ◽  
Proper Elements ◽  
N Body Problem ◽  
Double Averaging ◽  
The Mean ◽  
Osculating Elements ◽  
Mean Elements ◽  
Asteroid Families

In the context of the search of asteroid families (i.e. identification of minor planets as potential fragments of an old bigger body), the calculation of proper elements plays an important role. They are quasi-invariants of the motion, obtained by a double averaging process of the restricted N-body problem; firstly the osculating elements are averaged over the short periodic terms (namely the longitudes of the asteroid and of the perturbing planets) so to get the mean elements, and secondly, the mean elements are averaged over the long periodic terms (longitudes of the pericenters and of the nodes of the asteroid and of the perturbing planets) to obtain the proper elements.

scholarly journals What we know about Families of Asteroids

1989 ◽  
Vol 8 ◽  
pp. 273-279
Author(s):  
V. Zappala’
Keyword(s):  
Family Members ◽  
Parent Body ◽  
Classification Methods ◽  
Hypervelocity Impacts ◽  
Mass Distributions ◽  
Proper Elements ◽  
The Family ◽  
Families Of Asteroids ◽  
Asteroid Families ◽  
Degree Of Fragmentation

AbstractAsteroid families are considered for the most to represent fragments of collisional breakup of precursor bodies. If true, this offers the unique possibility to examine the interiors of large bodies and to study the processes of collision on a scale much larger than can be done in laboratory. Indeed, the general features of the mass distributions and of the ejection velocities of the family members can be interpreted in terms of collisional disruption of a parent body followed by self-gravitational reaccumulation on the largest remnant. However, several problems remain open: a) the degree of fragmentation in real families is generally lower than that observed for experimental targets; b) the relative velocities computed including also proper eccentricity and inclination differences are higher by about a factor 4 than those derived from semiaxes differences only; c) only very few of the presently proposed families have distributions of inferred mineralogies consistent with cosmochemistry. Further studies are needed, including better proper elements computation, classification methods, and new investigations on the physics of hypervelocity impacts.

Asteroid families: evidence of ageing of the proper elements

Icarus ◽  
2004 ◽  
Vol 169 (2) ◽  
pp. 341-356 ◽  
Author(s):  
A. Dell'Oro ◽  
G. Bigongiari ◽  
P. Paolicchi ◽  
A. Cellino
Keyword(s):  
Proper Elements ◽  
Asteroid Families

scholarly journals Asteroid Proper Elements: The Big Picture

1994 ◽  
Vol 160 ◽  
pp. 143-158 ◽  
Author(s):  
Zoran Knežević ◽  
Andrea Milani
Keyword(s):  
Point Of View ◽  
Dynamical Structure ◽  
Main Belt ◽  
Secular Resonances ◽  
Mean Motion Resonances ◽  
Mean Motion ◽  
Proper Elements ◽  
Big Picture ◽  
Linear And Nonlinear ◽  
Asteroid Families

Four perturbation theories presently used to compute asteroid proper elements are reviewed, and their results are briefly discussed (Milani and Knežević, 1990, 1992, 1994, for low to moderate eccentricity/inclination main belt objects; Lemaitre and Morbidelli, 1994, for high e, I objects; Milani, 1993, for Trojans; Schubart, 1982, 1991 for Hildas). The most important recent improvements are described, in particular those pertaining to the upgrades of the previous analytic and semianalytic solutions. The dynamical structure of the asteroid main belt, as defined by the low order mean motion resonances and by linear and nonlinear secular resonances, is considered from the point of view of the effects of these resonances on the accuracy and/or reliability of the computation of proper elements and on the reliability of the identification of asteroid families.

Families among the Hildas and Trojans

2018 ◽  
Vol 14 (A30) ◽  
pp. 24-25
Author(s):  
Tamara A. Vinogradova
Keyword(s):  
Empirical Method ◽  
Proper Elements ◽  
Asteroid Families

AbstractA search for asteroid families among the Hildas and Jupiter Trojans was performed with the use of a new set of proper elements. The proper elements were calculated by the empirical method. Besides well known families, several new probable families were found in addition.

scholarly journals Machine-learning identification of asteroid groups

2019 ◽  
Vol 488 (1) ◽  
pp. 1377-1386 ◽  
Author(s):  
V Carruba ◽  
S Aljbaae ◽  
A Lucchini
Keyword(s):  
Machine Learning ◽  
Hierarchical Clustering ◽  
Clustering Algorithms ◽  
Family Members ◽  
Parent Body ◽  
Clustering Methods ◽  
New Family ◽  
Hierarchical Clustering Methods ◽  
Rotational Failure ◽  
Asteroid Families

ABSTRACT Asteroid families are groups of asteroids that share a common origin. They can be the outcome of a collision or be the result of the rotational failure of a parent body or its satellites. Collisional asteroid families have been identified for several decades using hierarchical clustering methods (HCMs) in proper elements domains. In this method, the distance of an asteroid from a reference body is computed, and, if it is less than a critical value, the asteroid is added to the family list. The process is then repeated with the new object as a reference, until no new family members are found. Recently, new machine-learning clustering algorithms have been introduced for the purpose of cluster classification. Here, we apply supervised-learning hierarchical clustering algorithms for the purpose of asteroid families identification. The accuracy, precision, and recall values of results obtained with the new method, when compared with classical HCM, show that this approach is able to found family members with an accuracy above 89.5 per cent, and that all asteroid previously identified as family members by traditional methods are consistently retrieved. Values of the areas under the curve coefficients below Receiver Operating Characteristic curves are also optimal, with values consistently above 85 per cent. Overall, we identify 6 new families and 13 new clumps in regions where the method can be applied that appear to be consistent and homogeneous in terms of physical and taxonomic properties. Machine-learning clustering algorithms can, therefore, be very efficient and fast tools for the problem of asteroid family identification.

scholarly journals 10. A Statistical Investigation of Asteroid Families: Preliminary Results

1977 ◽  
Vol 39 ◽  
pp. 327-332
Author(s):  
A. Carusi ◽  
E. Massaro
Keyword(s):  
Orbital Evolution ◽  
Statistical Investigation ◽  
Correct Identification ◽  
Physical Origin ◽  
Preliminary Results ◽  
Clustering Technique ◽  
Proper Elements ◽  
Statistical Relevance ◽  
Asteroid Families

The correct identification of asteroid families is a prerequisite for understanding their nature, their orbital evolution and their physical origin. For this reason, a statistical investigation of asteroid families has been carried out, using a new clustering technique developed by A. I. Gavrishin. Proper elements for 2764 asteroids (1810 numbered and 954 Palomar-Leiden-Survey (PLS) asteroids) have been computed. Using these data, the Gavrishin method gives only ten significant classes. Five of them are coincident with the Hirayama families 1, 2, 3, 5, and the Flora group, that cannot be univocally subdivided. The PLS families are recognized. Furthermore many small-sized families reported by several authors lose their statistical relevance.

Simulating vortices and jets in deep atmospheres of gas giant planets

2020 ◽  
Author(s):  
Rakesh Yadav ◽  
Jeremy Bloxham ◽  
Moritz Heimpel
Keyword(s):  
Giant Planets ◽  
Self Organization ◽  
Surface Dynamics ◽  
Spherical Shells ◽  
Zonal Flows ◽  
Rich Picture ◽  
The Third ◽  
First Case ◽  
Dynamical Features ◽  
Over Time

<p>Decades of observations have painted a dynamic and rich picture of the atmosphere on Saturn and Jupiter. Both planets have a dominant prograde equatorial jet, and strong zonal flows that alternate in direction at higher latitudes, with Saturn also having a mysterious hexagon shape embedded in one of the polar jets. Both planets also have numerous vortices or storms of different sizes scattered on their surface. All these features are striking examples of turbulent self-organization. While observations abound, the physics behind the formation of these dynamical features is still uncertain. Two interpretations have emerged over time: In one, the surface features are shallow, extending to depths ranging from 10s to 100s of kilometers, while, in the other, they extend to 1000s of kilometers. Here we utilize the deep interpretation and investigate the properties of rotating convection in deep spherical shells. We present three cases: In the first case a giant polar cyclone, alternating zonal flows, and a high latitude eastward jet having polygonal patterns form simultaneously; The second case generates alternating zonal flows as well as numerous cyclones and anticyclones on various latitudes; And, the third case exclusively generates anticyclones with few being as large as Jupiter's great red spot. We discuss what drives these features in these turbulent simulations, and what can we learn from these cases about the interior and surface dynamics of Saturn and Jupiter. </p>

scholarly journals A comparative analysis of the outer-belt primitive families

2020 ◽  
Vol 643 ◽  
pp. A102
Author(s):  
M. N. De Prá ◽  
N. Pinilla-Alonso ◽  
J. Carvano ◽  
J. Licandro ◽  
D. Morate ◽  
...  
Keyword(s):  
Physical Properties ◽  
Spectroscopic Data ◽  
Planetary System ◽  
Parent Body ◽  
Comprehensive Analysis ◽  
Asteroid Belt ◽  
Main Belt ◽  
Solar System Formation ◽  
Visible Spectra ◽  
Asteroid Families

Context. Asteroid families are witnesses to the intense collisional evolution that occurred on the asteroid belt. The study of the physical properties of family members can provide important information about the state of differentiation of the parent body and provide insights into how these objects were formed. Several of these asteroid families identified across the main belt are dominated by low-albedo, primitive asteroids. These objects are important for the study of Solar System formation because they were subject to weaker thermophysical processing and provide information about the early conditions of our planetary system. Aims. We aim to study the diversity of physical properties among the Themis, Hygiea, Ursula, Veritas, and Lixiaohua families. Methods. We present new spectroscopic data, combined with a comprehensive analysis using a variety of data available in the literature, such as albedo and rotational properties. Results. Our results show that Themis and Hygiea families, the largest families in the region, present similar levels of hydration. Ursula and Lixiaohua families are redder in comparison to the others and present no sign of hydrated members based on the analysis of visible spectra. Conversely, Veritas presents the highest fraction of hydrated members. Conclusions. This work demonstrates a diverse scenario in terms of the physical properties of primitive outer-belt families, which could be associated with dynamical mixing of asteroid populations and the level of differentiation of the parental body.

scholarly journals Asteroid Family Identification: History and State of the Art

2015 ◽  
Vol 10 (S318) ◽  
pp. 16-27 ◽  
Author(s):  
Zoran Knežević
Keyword(s):  
State Of The Art ◽  
The State ◽  
Classification Methods ◽  
Data Set ◽  
The Third ◽  
Proper Elements ◽  
The Future ◽  
History Of ◽  
Asteroid Families ◽  
Collisional Evolution

AbstractThe history of asteroid families, from their discovery back in 1918, until the present time, is briefly reviewed. Two threads have been followed: on the development of the theories of asteroid motion and the computation of proper elements, and on the methods of classification themselves. Three distinct periods can be distinguished: the first one until mid-1930s, devoted to discovery and first attempts towards understanding of the properties of families; the second one, until early 1980s, characterized by a growing understanding of their importance as key evidence of the collisional evolution; the third one, characterized by an explosion of work and results, comprises the contemporary era. An assessment is given of the state-of-the-art and possible directions for the future effort, focusing on the dynamical studies, and on improvements of classification methods to cope with ever increasing data set.

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