Appreciate the detailed response. I was aware that the known bodies that could possibly give us a close call are relatively small; you show that even a small body like Chiron could tweak things, albeit just a wee bit. I would assume then that larger bodies would do considerably more tweaking...
Our planet being smacked by a huge asteroid is a common doomsday trope. But what if our planet didn't actually get smacked but came close to getting smacked? Could a sufficiently large body, or perhaps a group of several large bodies, pass close enough to alter the workings of the Milanković...
Glad to be aboard. I have a layman's interest in things like Milanković cycles, and I was looking for a place to discuss such with those more knowledgeable than I am.