All Tables

Table 1: Summary of the dynamical properties of the bodies injected into the $\nu _{6}$ , 3:1 and 5:2 powerful resonances studied by different authors. The median lifetimes ( Half-Life) of bodies initially in each of those resonances and the median times required to cross the orbit of the Earth ( $T_{\rm cr}$ Earth) have been derived by Gladman et al. (1997). Bottke et al. (2002) determined the median times spent in the NEA region ( $T_{\rm NEA}$ ) for bodies coming from the different resonant regions. On the other hand, the typical end states were analyzed by Gladman et al. (1997) who followed the orbital histories of more than one hundred particles injected into each resonance for up to $\sim$ 100 Myr. Finally, the mean collision probabilities with Earth ( $P_{\rm col}$ Earth), integrated over the lifetime in the Earth-crossing region, were derived by Morbidelli & Gladman (1998).
Table 2: Some of the most important dynamical results derived by Bottke et al. (2002) for bodies coming from the different NEA source regions. The sources studied by these authors were the $\nu _{6}$ and 3:1 resonances, the intermediate source Mars-crossing (IMC) population (namely, Mars-crossers below the $\nu _{6}$ ), the Outer Main Belt (OB) and the Jupiter-family comets. $N_{\rm NEA}$ (H< 18) represents the steady-state number of NEAs with an H magnitude smaller than 18, which is roughly 1 km in size. On the other hand, $\tau$ (Myr^-1) gives the number of bodies injected into the NEA region per million years while $T_{\rm NEA}$ (Myr) is the mean dynamical lifetime spent in the NEA region.
Table 3: Mean values for the intrinsic collision probability $\langle Pi_{\rm c} \rangle$ and the impact velocity $\langle V \rangle$ for the different populations of our model.
Table 4: Values for $f_{{\rm ke}_{0}}$ and $\gamma$ for the different populations of our model.