1781 - William Herschel sees what he at first thinks is a comet. However, it is shaped like a disc and orbits the Sun beyond Saturn. He declares it a planet. It is the first planet discovered by using a telescope.
1787 - Herschel discovers the moons Titania and Oberon.
1829 - Observers find that Uranus is tilted on its side.
1851 - English astronomer William Lassell discovers the moons Ariel and Umbriel.
1948 - Astronomer Gerard Kuiper discovers the last of the five major moons, Miranda.