I apologize for straying from the subject of your post, and I find that fascinating. I had thought that the orbits would have become more and more stable with time. I had no idea Mercury could stray from the fold.

And, I've read many times that Earth's Moon was formed by a collision between Earth and a "Mars-like" object. Well, where is that object? Is it indeed Mars, but it happened so long ago that there isn't a scintilla of evidence on observable Mars? Is it an object that just kept going and wandered out of the Solar System?

Or were things so poorly formed it could have been incorporated into Venus, Mars and maybe Mercury.

Someone must have an idea.

Thanks.

Arf