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Impact and Explosion Effects impacts usermanual usermanual
          by Keith A. Holsapple theory theory
hit counter: v 4.02
© 2003,2007,2015,2017,2018,2020
K. A. Holsapple
explosions Crater DataBase Crater DataBase

The Target:
Geology Type:
Target Type:
Here are generic values for the above geology, Choose "Other" to change them:

Mass density:
Target Cohesion (lab scale):
Assumed Cohesion at this crater scale:
Friction Angle:
Porosity (%):

Surface Gravity

To gravity or asteroid size "Other":


Note that the pressure effects are not known for most cases..

The Explosive:
Explosive Type:

Explosive Weight (Yield)
(equiv TNT weight for Nuclear)

Depth of Burst
PiV versus Pi2
plot from:


To Change Values select "Other":

Specific Energy:
Actual Diameter:
and the Energy is:
To Change select "Other":
+ means buried, scaled to tnt radius

DOB Value:

The Impactor:
Impactor Material:

To Change Values select "Choose":

Impactor Density
Impactor Diameter

(or choose crater diameter below):


From Vertical:

Normal Component:
Plot PiV (type below) versus Pi2 for a range of impactors

So the Mass is: and the Energy is:

The Excavation Crater Size is:
Show me the Profile:

Crater Diameter

(for impacts, can input this and solve for impactor)


Crater Volume
(below original surface)

Crater Mass
(the volume * the initial density)

Ejecta Mass
This needs to be decreased a lot for porous asteroids, that will be updated soon?
Rim Diameter
Lip Height
Formation Time
Melt Mass
Vapor Mass
crater mass/impactor mass
And it is in the Cratering Regime
For this brittle material and defined gravity, craters are spall craters
if their excavation diameter as given above is less than meters
So the Final Crater is a Spall Crater, Its Size is:

(The values in the output boxes above now are for the central excavation pit crater, the spall crater is indicated here:)

An example spall crater with a central pit:
The Average Spall Diameter
Depth (same as excavation)
Spall Crater Volume
(choose the percent or the velocity)
percent of the total, or:
of the mass is ejected with velocity greater than

Ejecta escaping from asteroid: But for this asteroid, the escape velocity is: m/s
so % or kg of the ejecta escapes
Source specific energy:

Required to bust it (Q*):