It is well known that collisions progressively modify the observable properties of asteroids. Unfortunately several uncertainties affect the physics of energetic collisions involving asteroids - and, more in general, massive bodies. The main open question is the value of their impact strength, i.e. the specific energy required for fragmentation. It depends on - not completely known - properties of scaling from the sizes typical of laboratory experiments to astronomical sizes and also on the - even more uncertain - effect of previous collisions, which created fractures and complex internal features in the structure of both impacting bodies. In this paper some consequences concerning the formation of dynamical families are discussed in detail. It is argued that the possible weak family solution recently suggested and seemingly able to reproduce the properties of a family such as Koronis may be consistent with the observed mass distribution but entails an overwhelming amount of fast rotators and binary asteroids. In turn this may also affect the observable spin distribution. Finally, the probability of a suitable parent collision is estimated, showing that this kind of events may take place but only a very few times during the whole history of the Solar System.
Fitting the mass distributions of Koronis family: new ideas and related physical constraints
PAOLICCHI, PAOLO;LA SPINA, ALESSANDRA;
2002-01-01
Abstract
It is well known that collisions progressively modify the observable properties of asteroids. Unfortunately several uncertainties affect the physics of energetic collisions involving asteroids - and, more in general, massive bodies. The main open question is the value of their impact strength, i.e. the specific energy required for fragmentation. It depends on - not completely known - properties of scaling from the sizes typical of laboratory experiments to astronomical sizes and also on the - even more uncertain - effect of previous collisions, which created fractures and complex internal features in the structure of both impacting bodies. In this paper some consequences concerning the formation of dynamical families are discussed in detail. It is argued that the possible weak family solution recently suggested and seemingly able to reproduce the properties of a family such as Koronis may be consistent with the observed mass distribution but entails an overwhelming amount of fast rotators and binary asteroids. In turn this may also affect the observable spin distribution. Finally, the probability of a suitable parent collision is estimated, showing that this kind of events may take place but only a very few times during the whole history of the Solar System.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
