Planetary Collision Calculator
This web tool calculates the outcome of collisions between
gravity-dominated bodies and generates collision outcome maps. The
scaling equations are appropriate for collisions onto planetary bodies
larger than about 1 km. Other online tools calculate the outcomes
for impact cratering events. The method is
Leinhardt, Z. M., and S. T. Stewart. Collisions between
Gravity-Dominated Bodies: 1. Outcome Regimes and Scaling
Laws. Astrophysical Journal, 745, 79 (27pp),
The impact angle axis is scaled by probability such that the
horizontal extent of each regime is proportional to the likelihood
of that collision outcome. Mlr is the mass of the largest remnant
after the collision; Mtot is the sum of the projectile and target
mass; Vesc is the mutual escape velocity. Catastrophic disruption
is defined as the specific energy needed to gravitationally
disperse exactly half the total mass. Note that between perfect
merging and hit-and-run, there is a graze-and-merge regime. Some
perfect merging outcomes (e.g., for Mprojectile <<
Mtarget) include impact cratering events.
The 'Save PNG' button will generate an image from the html5 canvas
Partial wish list: Add reverse impact calculation for erosion of projectiles in hit-and-run events; add optional graze-and-merge regime; add optional probability scaling for velocity axis.
Please email problems/corrections to sts at ucdavis.edu
Updated September 2018.