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Article
Topical Issue on Highlights of Planetary Science in Italy
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Article
Retrograde spins of near-Earth asteroids from the Yarkovsky effect
Dynamical resonances in the asteroid belt are the gateway for the production of near-Earth asteroids1 (NEAs). To generate the observed number of NEAs, however, requires the injection of many asteroids into those ...
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Article
Abstracts
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Chapter and Conference Paper
Collisional Evolution of the Asteroid Size Distribution: A Numerical Simulation
We have carried out a set of numerical simulations of the collisional evolution of the main asteroid belt, based on some models of fragmentation and cratering events consistent with the available experimental ...
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Article
Is Nereid a binary satellite?
If real, Nereid's recently observed large photometric variations (Schaefer and Schaefer, 1988) can be explained by modelling this Neptunian satellite as a quasi-contact binary system made of two similar, ellip...
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Article
Formation of binary systems and protoplanetary discs: A unified approach
We develop a new thermodynamic approach to the problem of the last stages of star formation, when a collapsing fragment evolves adiabatically into its final state: single protostar, surrounded or not by protop...
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Chapter and Conference Paper
Asteroid Families
The dynamical and physical studies of asteroid families are reviewed. Some recent numerical results show that the issue of proper elements has to be reconsidered, especially concerning the effect of the proxim...
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Chapter
The Shapes and Strengths of Small Icy Satellites
In the set of small icy satellites of Saturn recently imaged by the Voyager probes, we can observe the transition from irregularly shaped, strength-dominated objects to larger, gravity-dominated bodies with sh...
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Chapter and Conference Paper
On the Rotation of Cometary Nuclei and Small Asteroids
The spin rate distributions of comet nuclei and small asteroids are compared, and it is shown that Whipple’s (1982) finding of a faster average rotation for the asteroid sample was due to observational biases....
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Article
Shapes of asteroids compared with fragments from hypervelocity impact experiments
Light-curve observations have shown that most asteroids are non-axially symmetrical in shape, probably as a result of fragmentation undergone by objects with negligible gravitational binding1. Some earlier labora...
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Article
The shape and structure of Mimas
The Voyager images have shown that Mimas and Enceladus have “regular” shapes, with topography of the order of 1% of the diameter. Therefore, we can compare the global shapes of these satellites with the corres...
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Article
The shape of the small satellites of Saturn: Gravitational equilibrium vs solid-state strength
In the set of small satellites of Saturn recently imaged by the Voyager probes, we can observe the transition from irregularly-shaped, strength-dominated objects to larger, gravity-dominated bodies with shapes...
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Article
Effect of the magnetic pressure on cloud evolution
The effect of the magnetic pressure on gravitational collapse leading to star formation is analysed for a wide range of masses and initial values of the temperature and of the field. The collapse time increase...
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Chapter and Conference Paper
Asteroid Rotation Rates: Comparison between Theory and Observations
Harris’ (1979) theory on the collisional evolution of the asteroid spin rates is compared with the observational evidence provided by the statistics of photometric data. The resulting discrepancies can be qual...
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Chapter and Conference Paper
The Shape of Small Solar System Bodies: Gravitational Equilibrium vs. Solid-State Interactions
We discuss the new data on the shape of small planetary satellites and asteroids, comparing them with the theory of equilibrium figures for self-gravitating masses. This comparison allows to obtain interesting...
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Chapter and Conference Paper
Asteroid Collisional Evolution: Outcomes of Catastrophic Impacts
We discuss how catastrophic collisional events have influenced some outstanding properties of asteroids, like their structure, rotation, shape and family membership. The ultimate outcomes of the collisional ev...
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Article
Lifetime of an elliptical ring around Uranus
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Article
Gravitational phase transitions and the late-type stars
A scale transformation is obtained which allows the Hertel and Thirring gravitational phase transition theory to be extended to more generalized astrophysical conditions. It is shown that by means of this tran...
