# Question on crater formation

1. Oct 21, 2004

### AstroCook

Hi all, I'm a sixth year student in Scotland hoping to go onto study astrophysics at university. Keeping with this i have chosen to do my project on the formation of craters from meteor impacts.
I am wondering if anyone could direct me to a site or suggest some advice on going about this investigation. I was planning on a simple experiment using a metal ball and a box of sand with my variables being the mass of the object, courseness of the sand and height at which the ball is released.

Hope someone can lend a hand and sorry about the length of the thread :tongue:

Thank you

2. Oct 21, 2004

### Integral

Staff Emeritus
First a qualifier, I am not an expert in crater formation.

I am not convinced that your proposed experiment will yield meaningful results. Consider that meteors tend to break up on impact. This statement is based on the fact that we can calculate the energy of the meteor based on the size of the crater, I do not think that they have ever found a single piece, in or under a crater, big enough to cause the crater. How often will your ball bearing breakup upon impact with the sand? I think you will need to find a impact surface which is bound tighter together and a "meteor" which is less less tightly bound.

Then comes the issue of impact energy, how do you scale that? It will be a very difficult problem to find the appropriate combination of material properties and velocity to actually model the situation experimentally.

3. Oct 21, 2004

### meteor

Hi, meteor here
Maybe this can help
http://arxiv.org/abs/astro-ph/0402051
The paper contains an analysis of the frequency distributions vs. diameter, of the 42,000 craters contained in the Barlow Mars Catalog

4. Oct 22, 2004

### Phobos

Staff Emeritus
Welcome to Physics Forums, AstroCook!

I seem to recall hearing about some similar research...perhaps in relation to studies on the KT event. Search the literature. From what I recall, they weren't dropping ball bearings into sand but were firing them with powerful guns in order to simulate the actual impact velocities.

5. Oct 22, 2004

### Chronos

6. Oct 26, 2004

### ThomasJoe40

Hi, AstroCook, I am quite interested as well. I am, actually a freshman at UCL astronomy and physics department, hehe, and my first practical session on astronomy is actually about impact craters...

I don't know if this would help: http://www.solarviews.com/eng/vencrate.htm, it is an introduction on the craters on Venus. Craters on Venus is quite characteristic and totally different from other planets due to some nature of the planet (I guess you may already known this)... anyway, another one is a reference book called Planetary Landscapes by Greeley, R. London, Allen and Unwin, 1985, in that book, pp 39 - 43 general process, pp 95 - 98 Lunar craters, pp 118 - 122 Mercurian craters, pp 173 - 174 Martian craters, pp 139 - 142 Venusian craters...

OK, hope that helps, and... welcome to the forum¬¬

7. Nov 3, 2004

### AstroCook

Thanks

hey all,
thanks for all the replies and sorry for not posting sooner. I discussed the point raised in this thread with my teacher and we decided that the more basic the better. In this experiment i will be looking to see if a relationship can be established between the dimensions of the crater and the speed/mass of the impacting object. Marks will be given generally for good practice, identfying possible errors and the suggestion of improvements, this is why my teacher says that the simplicity will serve me well.

Thanks again for all your help, ill be sure to add the site and suggestions to my project.

8. Nov 7, 2004

### meteor

This, today
http://www.newscientist.com/news/news.jsp?id=ns99996611
"The discovery of the largest field of impact craters ever uncovered on Earth is the first evidence that the planet suffered simultaneous meteor impacts in the recent past. The field has gone unnoticed until now because it is partially buried beneath the sands of the Sahara desert in south-west Egypt"

So, AstroCook, do you have your bags prepared for a trip to the Sahara?

9. Nov 24, 2004

### AstroCook

Sahara craters

Cool, sounds like a plan but I think I'll need to leave it for my Masters or Phd days, .