N-Body Problem - need a simple answer for a created planetary system

[Althistorybuff]

Ok, I'm trying to get a grasp on the n-body problem as I want an earth-like planet with two large moons of roughly the same size. One scenario is same sized moon twice as far out or a closer moon (Io-type) half the distance between Earth and Luna. Basically, they would NOT be sharing an orbit or Lagrange Point.

From what I gather, the Earth isn't massive enough to hold both bodies without them gravitationally pushing one another about too much, at least over medium to long term. I'd like to have this be relatively stable for billions of years. No crashing into the Earth of being expelled.

 

Is this possible?

 

Everything I hear says no, that the system would become unstable sooner rather than later, though I don't know the definition of "sooner" or "later".

Even the Sun-Rest of Solar System (500 to 1) or the Jupiter-60 moons System has a level of interaction (thousands to one) gravitationally.

Is the idea of a 2nd large moon around Earth not possible?

 

If not, what would be the constraints?

I don't need the math, just an idea of how long this would last.

Is there a "golden ratio" when the gravity of the large body (Earth) would MOSTLY cancel out the two moons' gravitational effect upon one another? 500 to 1, 1000 to 1?

 

Would creating a certain resonance with their orbits (2 to 1, 3 to 2, whatever) make a difference?

Thanks.

Edited March 22, 2017 by Althistorybuff

[Sensei]

Google for "star system simulator online"

https://www.google.com/?#q=star+system+simulator+online

There are available simulators in web browser window where you can enter mass of object, start radius, and start velocity of object.

 

After starting simulator you will observe how they behave over time.

 

You could try this for instance:

http://www.stefanom.org/spc/

Edited March 22, 2017 by Sensei

[Althistorybuff]

Thanks.

[KipIngram]

Google for "star system simulator online"

https://www.google.com/?#q=star+system+simulator+online

There are available simulators in web browser window where you can enter mass of object, start radius, and start velocity of object.

 

After starting simulator you will observe how they behave over time.

 

You could try this for instance:

http://www.stefanom.org/spc/

 

Oh my, that is fun.