The random walk of Main Belt asteroids: orbital mobility by non-destructive collisions

Abstract

Non‐destructive collisions among Main Belt asteroids have effects on their orbits due to the transmission of linear momentum. The efficiency of this mechanism depends on several parameters which are currently poorly known. The most critical aspects are (i) the inventory and size distribution of small Main Belt asteroids, with sizes well below a few kilometres; (ii) the energy threshold for collisional fragmentation and fragment dispersion and (iii) the efficiency of linear momentum transfer. In spite of these difficulties, a general statistical model of the dynamical effects of non‐destructive collisions can be developed, and is presented here. Based on this model, the consequences of different assumptions concerning the asteroid size distribution and collision physics are computed and discussed. Quantitative evaluations of the collisionally induced orbital mobility in different possible scenarios are presented.

The (not so) peculiar case of the Padua family

“…The value of the exponent α found by Ivezic̀ et al (2001) and Parker et al (2008) based on the Sloan Digital Sky Survey in the size range between 0.4 and 5 km is −2.3, in disagreement with that found by Tedesco, Cellino & Zappalá (2005). The exact value of this exponent is important to understand the role that low‐energy collisions may have played in the dynamical diffusion of asteroid families (Dell'Oro & Cellino 2007). Larger absolute values of α produce higher diffusion rates in a , e and sin i , and this should produce notable effects on the proper element distribution of asteroid families.…”

“…The question regarding the possible age of the Padua family will be further addressed in . For what concerns size distributions, other authors (Dell'Oro & Cellino 2007) use a different approach and obtain the exponent of the cumulative distribution in terms of diameters rather than absolute magnitudes. Using the relationship where D 0 = 1329 km, H is the asteroid absolute magnitude and p V is the geometric albedo (see for a discussion of the albedo values in the area of the Padua family), it is possible to obtain the diameters of the Padua classical and frequency families.…”

“…Recently, Dell'Oro & Cellino (2007) analysed the role that low‐energy collisions may have played in the orbital diffusion of asteroids. Non‐destructive collisions among Main Belt asteroids have effect on their orbits due to the transmission of linear momentum.…”

In search of the source of asteroid (101955) Bennu: Applications of the stochastic YORP model

“…For this reason, we do not include here the effects of encounters with massive asteroids (e.g., Carruba et al, 2003Carruba et al, , 2013 and similar reference therein) and collisions capable of modifying the orbits of asteroids (e.g., Dell'Oro and Cellino, 2007). The passage of migrating asteroids through weak mean motion and secular resonances in the inner main belt, which may modestly affect their eccentricities and inclinations (e.g., Bottke et al, 2001;Carruba et al, 2005), were also neglected, partly because including them is computationally expensive but also because most do not strongly affect the delivery rate of small asteroids to powerful resonances capable of delivering them to planetcrossing orbits.…”

Secular evolution of asteroid families: the role of Ceres

“…However, families evolve significantly since the epoch of their formation as a consequence of different processes and perturbatations, such as: chaotic diffusion (Nesvorny et al 2002, Novaković 2010, Novaković et al 2010a, semi-major axis drift due to the Yarkovsky effect (Farinella & Vokrouhlicky 1999, Bottke et al 2001, Spoto et al 2015, secondary collisions (Marzari et al 1999, Milani et al 2014, non-destructive collisions (Dell'Oro & Cellino 2007), and close encounters with massive asteroids (Carruba et al 2003, Novaković et al 2010b.…”