Binary dwarf planets: Dee and Dum

[jfull]

It would be neat to see an addition of a binary system of 2 small (about Bop size, give or take) planetoids orbiting at some point in between the orbits of the current planets. They would have different masses, and might slightly differ from one another in color or features.

Basically they would represent a pair of asteroids.

The main issue with this idea is that I can't think of how the SOIs of two objects orbiting each other would work in KSP.

[leax256]

simply put they don't, least not well.

[jfull]

Well, I did have an idea that there would be a SOI around system as a whole, centered at the invisible barycenter of the two, and then they'd each have their own, far enough apart that there'd be no overlap. I'm not sure if it would actually work out if you did the proper math though.

[Deathsoul097]

The way I see this working is an empty is between the two, and they orbit it as moons exactly parallel to each other, and on the exact same orbit. The only problem would be the bugs that would be caused by the empty. If you went directly into it, it would be like the sun back in 0.13, kraken attack, nearly destroying your computer, and firing the ship out of the solar system, right into the jaws of the deep space kraken, that would rip your craft apart.

[Dunbaratu]

I don't think this is doable for the same reason we don't have L1 Lagrange points. To do it really properly would require calculating gravity as a 2-body problem rather than a 1-body problem with the sphere of influence technique.

Problems with trying to do it with the current 1-body model:

1 - It would have an odd fold in space at the boundary between the SOI's. It would behave really screwy in the space between the two planets. Instead of moving across a nice mild gradient gently transitioning from pulling toward Dee to pulling toward Dum, you'd instead hit a line where it would just instantly JUMP from pulling strongly one way to pulling strongly the other. This will interfere with trying to pull off nice figure-8 paths.

2 - The current model doesn't support the idea of "equal" planets with SOI radii that have equal "rights" butting up against each other. Instead it has a parent/child tree relationship of SOI's. i.e: Mun's SOI is inside Kerbin's SOI is inside Sun's SOI. So to do this you'd need to make one of the two twin planets be a "moon" of the other one, which sort of gets into the next problem.

3 - The SHAPE of the SOI boundary between the two bodies would be wrong. What you'd need would be something akin to when two spherical soap bubbles intersect and form a common wall between them, and that common wall is not shaped like a sphere but gets much flatter between them. But the current model can't do that. It puts spheres inside spheres inside spheres and they all have symmetrical shapes. No egg-shaped SOIs or SOI's flattened on one side are currently supported by the model the game uses.

Don't get me wrong. I'd love this, especially for the screenshots alone of landing on one planet and having the HUGE other planet taking up most of the sky above. But it would require a change in the main game engine to support it.

Edited December 9, 2013 by Steven Mading

[NovaSilisko]

It could be done, but only from a visual standpoint. You could make an invisible planet and then give it two "moons" and it'd look alright, but from a gameplay standpoint that just doesn't work. At the barycentre of this system would be a gravitational singularity - which, if passed, would probably hurl your ship off into the cosmos at FTL velocities (like the sun did before it had a surface)

Edit: aaaactually everything I just said has been stated by other people in the thread. Carry on.

[jfull]

It could be done, but only from a visual standpoint. You could make an invisible planet and then give it two "moons" and it'd look alright, but from a gameplay standpoint that just doesn't work. At the barycentre of this system would be a gravitational singularity - which, if passed, would probably hurl your ship off into the cosmos at FTL velocities (like the sun did before it had a surface)

Yeah, after thinking about it on my own for a bit, most of that stuff occured to me.