The current impact earth calculator was created by Robert Marcus, H. Jay Melosh, and Gareth Collins. 

 

The original impact crater calculator was created by H. Jay Melosh and Ross A. Beyer. 

This was a short routine to evaluate the scaling equations to determine the diameter of a crater given details on the nature of the projectile, conditions of impact, and state of the target. The transient crater diameter was evaluated by three independent methods, yield scaling, pi-scaling and Gault's semi-empirical relations supplemented by rules on how crater size depends on gravity and angle of impact.

See Melosh, Impact Cratering, chapter 7 for more details.

Copyright 1996, 1997 and 1998 by H. J. Melosh