The planet problem is identical to the atom problem .... you want absolute space size doesn't matter.
So lets not even worry about planets or atoms which are too hard to test for you and I ...
we have 3 marbles.Set the 3 marbles into your model we can both easily do it and test things.
You can't do it can you .... you are a mechanical/electrical guru why can't you do it?Why Newton?Atom/planet or marble they all work it's the same universe.
YOUR PROBLEM IS CLASSIC PHYSICS IS WRONG and you are stuck ... I know it, you know it as does everyone.
It's called the collapse of Newton's universe ... PLOP .. universe all gone
Here is the best model anyone has ever been able to make for a museum and it's not very good even children have trouble with it
SO WE HAVE A GOOD SETUP WE CAN BOTH TEST CALLED 3 MARBLES AS CAN ALL THE READERS
WE CAN MAKE IT 2 MARBLES IF IT HELPS
SO LETS TEST ... COME ON NEWTON 
The best bit is we haven't even got to the hard bit of stacking atom models on top of atom models which we should be able to do to build a solid and then apply pressure .... oh the problem gets a lot worse Newton.
Are you feeling rather silly yet Newton?
Absolute space is dead absolutely marbles tells me so!!!!!
