What if...

[flowen8]

Two planets were to collide in game, what would happen?

[Clamps]

Install hyperedit and find out.

[flowen8]

Oh yeah hyper edit, i forgot about that.

[AustralianFries]

If it ever happened by default, the game would probably either crash, or theyd just go through each other.

[Sbowyer28]

The first thing is anything in the smaller planets SOI would get flung out f the solar system at the seed of light then they'd just pass through each other annhilating any craft in the way

[Richy teh space man]

They just pass through each other, so long as your active vessel is on the surface.

If you want to try it when they're not on the surface, hyperedit it..

[Pipcard]

I don't think the game is designed to simulate planetary collisions.

[Sirrobert]

Scott Manley has a vid where he throws a player made astroid (from a mod) at kerbin, and they just bounce of eachother. I think the terrain is indistructable

[M5000]

Yup, depending on what you're looking at, they either just clip through each other or they bounce off.

Stock/in-game planets will just clip through each other. Though, I do always tend to wonder how their orbital mechanics would be affected...

[mushroomman]

What if you had a craft on Minimus, and you flung Kerbin at it? What would happen to the craft?

[thederper121]

What if you had a craft on Minimus, and you flung Kerbin at it? What would happen to the craft?

It may either explode or get flown off to somewhere because of the gravity effects.

[SuperWeegee4000]

Who needs another planet? Send up a rocket with a long scaffold on top and joust Danny style.

The game ensures that planets cannot collide, so short of installing HyperEdit, no collisions are possible. There are two planets that have orbits that ensure they can't encounter each other... was it Eeloo and Jool? The info's on the Wiki somewhere....