So Dan, can you show us a...

[Quibit]

Video of Earth and Venus colliding in Universe Sandbox 3!!! I think they should explode into many new pieces, so the pieces could form a new planet! (according to "The Universe" documentary "10 ways to destroy the earth" Watch it on YouTube and you might get some ideas for 3!

[DiamondMiner10]

I love that show! Finally someone mentions it! Also the part when they crash together i am not sure if they come back together but i think its a great idea.

[Xriqxa]

Gravity should pull them back together to create a ~2 earth amass planet, it depends whether you are talking about a crossed orbit collision or launching them at each other at high speed