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Papers by Paolo Farinella
Icarus, 1982
The role of catastrophic collisions in the evolution of the asteroids is discussed in detail, emp... more The role of catastrophic collisions in the evolution of the asteroids is discussed in detail, employing extrapolations of experimental results on the outcomrs of high-velocity impacts. We determine the range of the probable largest collision for target asteroids of different ...
Planetary and Space Science, 1994
Title: Asteroid collisional evolution: Results from current scaling algorithms. Authors: Davis, D... more Title: Asteroid collisional evolution: Results from current scaling algorithms. Authors: Davis, Donald R.; Ryan, Eileen V.; Farinella, Paolo. ...
Icarus, 1993
A model is presented for the ejection of fragments from impact cratering or breakup of existing a... more A model is presented for the ejection of fragments from impact cratering or breakup of existing asteroids and the chance insertion of the escaping fragments into the 'dangerous' regions of the phase spaces close to the 3:1 and g = g6 resonances, where chaotic behavior may arise. It is found that both resonances are effective channels for fragment collection and delivery and their efficiencies are of the same order of magnitude, but they sample in a different way the orbital elements and the physical properties of the parent objects. Although this depends on the poorly known size distribution of small asteroids, it seems possible that a large fraction of near-earth asteroids and meteorites are generated by a small sample of the asteroid population, mostly located in the vicinity of resonances, whose average properties do not necessarily coincide with those of the general population. The g = g6 resonance is probably an effective fragment delivery channel in the moderate-inclination regions near 2.4 and 2.7 AU and near the inner edge of the belt.
Nature, 1994
ASTEROID families are groups of objects produced in disruptive collisions of a parent body. Altho... more ASTEROID families are groups of objects produced in disruptive collisions of a parent body. Although family members are widely dispersed in real space, they cluster in the parameter space defined by their so-called proper elements, and can thus be distinguished from the ...
Astronomical Journal, 1990
... I. IDENTIFICATION BY HIERARCHICAL CLUSTERING AND RELIABILITY ASSESSMENTVINCENZO ZAPPALA AND A... more ... I. IDENTIFICATION BY HIERARCHICAL CLUSTERING AND RELIABILITY ASSESSMENTVINCENZO ZAPPALA AND ALBERTO CELLINO Osservatorio Astronomico di Torino, 1 ... As pointed out by Carusi and Valsecchi ( 1982), on such basic issues as the number of existing ...
Icarus, 1992
Wetherill's (1967) algorithm is presently used to compute the mutual collision probabilities and ... more Wetherill's (1967) algorithm is presently used to compute the mutual collision probabilities and impact velocities of a set of 682 asteroids with large-than-50-km radius representative of a bias-free sample of asteroid orbits. While collision probabilities are nearly independent of eccentricities, a significant decrease is associated with larger inclinations. Collisional velocities grow steeply with orbital eccentricity and inclination, but with curiously small variation across the asteroid belt. Family asteroids are noted to undergo collisions with other family members 2-3 times more often than with nonmembers.
Planetary and Space Science, 1994
Abstract Dohnanyi's [J. geophys. Res. 74, 25312554, 1969; in Physical Studies of Mi... more Abstract Dohnanyi's [J. geophys. Res. 74, 25312554, 1969; in Physical Studies of Minor Planets (edited by T. Gehrels), pp. 263295. NASA-SP 267, 1971] theory predicts that a collisional system such as the asteroid population should rapidly relax to a power-law ...
Astronomical Journal, 1998
Astronomical Journal, 1994
... II. EXTENSION TO UNNUMBERED MULTIOPPOSITION ASTEROIDS VINCENZO ZAPPALA AND ALBERTO CELLINO Os... more ... II. EXTENSION TO UNNUMBERED MULTIOPPOSITION ASTEROIDS VINCENZO ZAPPALA AND ALBERTO CELLINO Osservatorio Astronomico di Torino, Pino Torinese, Italy Electronic mail: zappala® astto2.astro.it PAOLO FARINELLA AND ANDREA MILANI1 Gruppo di ...
Icarus, 1991
By means of a new algorithm which generalizes the secondorder and fourth-degree secular perturbat... more By means of a new algorithm which generalizes the secondorder and fourth-degree secular perturbation theory of Milani and Kne~evi~ (1990, Celest. Mech. 49, 347-411), we find in the a-e-I proper elements space the location of secular resonances between the precession rates of the longitudes of perihelion and node of a minor body and the corresponding eigenfrequencies of the secular perturbations of the four outer planets. Among the most interesting implications of our findings, we can quote: (i) the fact that the g = g6 (or v6) resonance in the inner asteroid belt lies closer than previously assumed to the densely populated Flora region, providing a plausible dynamical route to inject asteroid fragments into planet-crossing orbits; (ii) the existence of another possible meteorite source near 2.4 AU at moderate inclinations, again through g --g6; (iii) the existence, confirmed by numerical experiments, of a region affected in a chaotic way by the s --s 6 (or vl6 ) resonance at semimajor axis = 2.2 AU and moderate inclination, where no asteroid is observed; (iv) the possible presence of some lowinclination "rings" between the orbits of the outer planets where no major mean motion or secular resonance lies very near, allowing minor bodies to survive long times without close encounters; (v) the fact that none of the secular resonances considered in this work exists beyond 50 AU, so that these resonances cannot be effective for transporting inward comets belonging to a possible Kuiper flattened disk. ~
Icarus, 1982
The role of catastrophic collisions in the evolution of the asteroids is discussed in detail, emp... more The role of catastrophic collisions in the evolution of the asteroids is discussed in detail, employing extrapolations of experimental results on the outcomrs of high-velocity impacts. We determine the range of the probable largest collision for target asteroids of different ...
Planetary and Space Science, 1994
Title: Asteroid collisional evolution: Results from current scaling algorithms. Authors: Davis, D... more Title: Asteroid collisional evolution: Results from current scaling algorithms. Authors: Davis, Donald R.; Ryan, Eileen V.; Farinella, Paolo. ...
Icarus, 1993
A model is presented for the ejection of fragments from impact cratering or breakup of existing a... more A model is presented for the ejection of fragments from impact cratering or breakup of existing asteroids and the chance insertion of the escaping fragments into the 'dangerous' regions of the phase spaces close to the 3:1 and g = g6 resonances, where chaotic behavior may arise. It is found that both resonances are effective channels for fragment collection and delivery and their efficiencies are of the same order of magnitude, but they sample in a different way the orbital elements and the physical properties of the parent objects. Although this depends on the poorly known size distribution of small asteroids, it seems possible that a large fraction of near-earth asteroids and meteorites are generated by a small sample of the asteroid population, mostly located in the vicinity of resonances, whose average properties do not necessarily coincide with those of the general population. The g = g6 resonance is probably an effective fragment delivery channel in the moderate-inclination regions near 2.4 and 2.7 AU and near the inner edge of the belt.
Nature, 1994
ASTEROID families are groups of objects produced in disruptive collisions of a parent body. Altho... more ASTEROID families are groups of objects produced in disruptive collisions of a parent body. Although family members are widely dispersed in real space, they cluster in the parameter space defined by their so-called proper elements, and can thus be distinguished from the ...
Astronomical Journal, 1990
... I. IDENTIFICATION BY HIERARCHICAL CLUSTERING AND RELIABILITY ASSESSMENTVINCENZO ZAPPALA AND A... more ... I. IDENTIFICATION BY HIERARCHICAL CLUSTERING AND RELIABILITY ASSESSMENTVINCENZO ZAPPALA AND ALBERTO CELLINO Osservatorio Astronomico di Torino, 1 ... As pointed out by Carusi and Valsecchi ( 1982), on such basic issues as the number of existing ...
Icarus, 1992
Wetherill's (1967) algorithm is presently used to compute the mutual collision probabilities and ... more Wetherill's (1967) algorithm is presently used to compute the mutual collision probabilities and impact velocities of a set of 682 asteroids with large-than-50-km radius representative of a bias-free sample of asteroid orbits. While collision probabilities are nearly independent of eccentricities, a significant decrease is associated with larger inclinations. Collisional velocities grow steeply with orbital eccentricity and inclination, but with curiously small variation across the asteroid belt. Family asteroids are noted to undergo collisions with other family members 2-3 times more often than with nonmembers.
Planetary and Space Science, 1994
Abstract Dohnanyi's [J. geophys. Res. 74, 25312554, 1969; in Physical Studies of Mi... more Abstract Dohnanyi's [J. geophys. Res. 74, 25312554, 1969; in Physical Studies of Minor Planets (edited by T. Gehrels), pp. 263295. NASA-SP 267, 1971] theory predicts that a collisional system such as the asteroid population should rapidly relax to a power-law ...
Astronomical Journal, 1998
Astronomical Journal, 1994
... II. EXTENSION TO UNNUMBERED MULTIOPPOSITION ASTEROIDS VINCENZO ZAPPALA AND ALBERTO CELLINO Os... more ... II. EXTENSION TO UNNUMBERED MULTIOPPOSITION ASTEROIDS VINCENZO ZAPPALA AND ALBERTO CELLINO Osservatorio Astronomico di Torino, Pino Torinese, Italy Electronic mail: zappala® astto2.astro.it PAOLO FARINELLA AND ANDREA MILANI1 Gruppo di ...
Icarus, 1991
By means of a new algorithm which generalizes the secondorder and fourth-degree secular perturbat... more By means of a new algorithm which generalizes the secondorder and fourth-degree secular perturbation theory of Milani and Kne~evi~ (1990, Celest. Mech. 49, 347-411), we find in the a-e-I proper elements space the location of secular resonances between the precession rates of the longitudes of perihelion and node of a minor body and the corresponding eigenfrequencies of the secular perturbations of the four outer planets. Among the most interesting implications of our findings, we can quote: (i) the fact that the g = g6 (or v6) resonance in the inner asteroid belt lies closer than previously assumed to the densely populated Flora region, providing a plausible dynamical route to inject asteroid fragments into planet-crossing orbits; (ii) the existence of another possible meteorite source near 2.4 AU at moderate inclinations, again through g --g6; (iii) the existence, confirmed by numerical experiments, of a region affected in a chaotic way by the s --s 6 (or vl6 ) resonance at semimajor axis = 2.2 AU and moderate inclination, where no asteroid is observed; (iv) the possible presence of some lowinclination "rings" between the orbits of the outer planets where no major mean motion or secular resonance lies very near, allowing minor bodies to survive long times without close encounters; (v) the fact that none of the secular resonances considered in this work exists beyond 50 AU, so that these resonances cannot be effective for transporting inward comets belonging to a possible Kuiper flattened disk. ~