The orbit of Pluto crosses the orbit of Neptune because the eccentricity of Pluto is much greater than Neptune and the rest of the Planets. This causes Pluto to stray into the path of the orbital plane of Neptune. Using a present day model to calculate a happenning of more than 100 years is a travesty but Pluto will come within 150000km or 0.001au on three separate years: 2161 2259 2417 Someone please correct me if I am wrong. Any input would be appreciated!!