universetoday.com
Discovery of Pluto - Universe Today
Once the planet Uranus was discovered, astronomers have suspected that there are probably more planets in the Solar System. Astronomers used Newtonian mechanics to predict Neptune from its perturbations of Uranus’ orbit. German astronomer Gottfried Galle found Neptune exactly where calculations predicted it should be. Now that they knew the method worked, astronomers set about … Continue reading "Discovery of Pluto"