Disruption of Icy Bodies

Catastrophic Disruption of Icy Bodies 9.3.4.I. Impact Strength of Water Ice... 

We use this relationship to discuss tlte disruption of icy bodies of planetary scale. 

Consider what happens in collisions of porous icy bodies when we apply two empirical equations, Eq.(5) and Eq.(6). Figure 12 shows a collisional state map separated by Vi-disp and Vj.acc described on the velocity-porosity plane. This map is calculated for 7 =100 km and rp 20 km. The icy body will be disrupted above the dashed line, and the mixture body will be disrupted above the dashed-dotted line estimated from Eq.(5). Reaccumulation of the fragments will occur below the solid line for both target bodies estimated from Eq.(6). To contribute to planetary growth, the impact condition must be... 

Four principal models have been proposed to explain the presence of alteration phases in chondritic meteorites. These models can be summarized as follows (i) reaction of anhydrous, high-temperature condensate phases with water vapor as the solar nebula cooled to temperatures below —375 K (e.g., Grossman and Larimer, 1974]) (ii) hydration of anhydrous dust in icy regions of the nebula during the passage of shock waves (Ciesla et al., 2003) (iii) alteration within small (tens of meters), ephemeral parent bodies that were subsequently disrupted and their altered components accreted with unaltered materials into the final asteroidal parent bodies (pre-accretionary alteration) (Metzler et al., 1992 Bischoff, 1998) and (iv) alteration within asteroidal parent bodies (Kerridge and Bunch, 1979 Zolensky and McSween, 1988). 

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