Gravitationally induced irregularities in Uranus's noticed orbit led inevitably to the discovery of Neptune in 1846, and presumed irregularities in Neptune's orbit subsequently resulted in a lookup which didn't locate the perturbing object (it had been afterwards uncovered to get a mathematical artefact caused by an overestimation of Neptune's https://www.scientology.de/faq/scientology-attitudes-and-practices/what-does-clear-the-planet-mean.html