[idea] Technically possible?

[FireGamersHD]

Hey Developers of the Game and other US² users,

• Is it technically possible that planets get a huge crater after an impact? (For example, after the impact of the moon)
  
  
  • And another Question. It is technically possible somehow if, for example the moon strikes the earth, the moon slowly falling apart?
    
    I hope something like that is implemented in one of the next updates. That would be Awesome!
    
    Greetings from Germany! I'm a big fan of Universe Sandbox ².
    
    (I hope for a reply)

[The Ventifact]

Well, impact craters have been in US2 from early on. Impact craters are somewhat generic right now, but later down the development road map, they'll be improved, I'm sure. It would be cool to see randomly generated craters!

And in the last update, they added "Total Body Fragmentation," which might be close to what you're asking. Assuming you already have the game, body fragmentation is under View > Simulation tab > Collision > Total Body Fragmentation. If you run the simulation at a slower time step, you'll slowly see the body fragment into pieces as it impacts another object. As of right now, it's not real fancy. No rough chunks of debris or rocky ejecta, but it does look nice. However, it's quite a step up from the previous iterations of body fragmenting.

[Greenleaf]

• Is it technically possible that planets get a huge crater after an impact? (For example, after the impact of the moon)
  

The real question is if it is physically correct that earth, post moon impact, has a huge crater... and it is not.
The larger the body, the softer the body, the shallower the crater will be.
Even without considering the heating from such an impact, the surface of Earth cannot support very large high differences. Without having the specific numbers, it is probably in the 20km range.

[Camacha]

Isn't that pretty much the same mechanism that prevents mountains from becoming much higher than they currently are? Even if you discount time and local ground make-up, there seems to be an obvious limit.

[The Ventifact]

Isn't that pretty much the same mechanism that prevents mountains from becoming much higher than they currently are? Even if you discount time and local ground make-up, there seems to be an obvious limit.

I don't think those are really related. Different forces drive the creation of land masses and mountains. Earthquakes, plate tectonics, and volcanism created what we see today. I can't remember specifically where I heard it (probably History Channel or something), Mount Everest grows taller every year due plate tectonics. And as long as there is still tectonic activity, the mountain will continue to grow in height as time goes on.

Actually, just found a link from National Geographic:

http://www.nationalgeographic.com/features/99/everest/roof.html

Says Everest grows 0.1576 inches (about four millimeters) each year. In another several million years, the mountain will probably be over 30,000 feet. We probably won't be around to see that.

Eh, a little of topic, but still very interesting. :)

[Greenleaf]

Isn't that pretty much the same mechanism that prevents mountains from becoming much higher than they currently are? Even if you discount time and local ground make-up, there seems to be an obvious limit.

Yes.
Someone else did a quick calculation here
https://talkingphysics.wordpress.com/2011/09/08/how-high-can-mountains-be/
which looks about right
Add to that the fact that mountains on earth are essentially floating on the fluid under the crust.