What are the recommended materials for modeling impact craters?

[UK1989]

Hi

Basically, I am doing an A level project, in which I am investigating impact craters.

I am modeling this by dropping ball bearings into sand, and measuring the depth and width of the resulting crater.

However, my results are quite unclear, and I would really appreciate some guidance on the trends that would be expected.

My main question : would you expect there to be a constant width-depth ratio as the height of the ball drop increases?
Would there be a constant ratio as the weight/radius of the ball increases?

Thanks, any help is much appreciated.

 

[AlephZero]

This site
http://www.tki.org.nz/r/science/science_is/activities/isact_models_craters_e.php suggests using flour not sand.

Flour grains are much smaller than sand and probably have less friction between the grains. That might help getting consistent results if you are doing "small scale" experiments.