Discovered 1888 Oct. 25 by J. Palisa at Vienna.
Named for an island in the northernmost part of the North Sea to which the ancients gave the name Ultima Thule. Its location has never been accurately ascertained. Some writers have thought it to be Iceland, Greenland, or the Shetland Islands. To the ancients, it was the northern limit of the habitable world. (Z 271)
The name is exceptionally appropriate because the planet’s orbit was the farthest from the Sun then known. Except for the special dynamical case of the Trojan asteroids and some other spectacular objects, which probably are cometary nuclei, Thule still occupies this position. It is very near the 3:4 commensurability of period with Jupiter.