On New Year’s Day, the New Horizons probe, the first space probe to visit Pluto, will zip past the Kuiper Belt object 2014 MU69 which will become the furthest object in our solar system visited by a space probe. Unfortunately, 2014 MU69 isn’t an easy designation to remember, nor does it roll off the tongue, and so the New Horizons team has come up with a much more poetic name for the object — Ultima Thule.
“Thule was a mythical, far-northern island in medieval literature and cartography. Ultima Thule means ‘beyond Thule’ — beyond the borders of the known world — symbolizing the exploration of the distant Kuiper Belt and Kuiper Belt objects that New Horizons is performing, something never before done.”
Ultima Thule is not an official International Astronomical Union name, just as Mars’ Mount Sharp is officially Aeolis Mons, and IAU officials will likely be just as annoyed by NASA scientists talking about “Ultima Thule” as they were about “Mount Sharp,” but it’s a good name, one chosen by the explorers who are going there.