we can predict the forward trajectory of nearly every major solar system object using first principles math and experimental observations and it predicts for ye

we can predict the forward trajectory of nearly every major solar system object using first principles math and experimental observations and it predicts for years into the future; every time we find another object in the solar system, we add its position and mass and the model gets slightyl more accurate. """As of DE421, perturbations from 343 asteroids, representing about 90% of the mass of the main asteroid belt, have been included in the dynamical model""" Using polynomial interpolation you can get more or less 100meter level accuracy for any major object at any time. If there are remaining large masses that we haven't identified, they must be fairly small, far, and very dark. (this is one of the most important achievements in human history and represents one of the longest scientific/religious activities; people have been predicting orbital paths for thousands of years.)