NASA’s New Horizons spacecraft recently made a flyby of Kuiper Belt Object MU69, nicknamed Ultima Thule, an object 4 billion miles from Earth that is the farthest object any spacecraft has ever explored. The foray into this region of outer space will provide scientists with a glimpse not into a distant part of a region never before seen up close by humans but also a look at a pristine celestial body that might provide clues as to how Earth formed. Scientists theorize that Ultimate Thule is likely the result of a collision that occurred shortly after the birth of the Solar System. The first images, taken 28,000 kilometers from the object, show a snowman-like appearance of “two connected sphere-like shapes held in contact by mutual gravity.”
So what does Ultima thule mean? Ultima thule is Latin and has been used over to the centuries to refer to an area of the world that is the most distant and inaccessible. In other words as NASA describes, it’s a place “beyond the known world.” The term was originally used in ancient Greek and Roman literature and cartography to denote a mythical island in the area furthest north. In classical and medieval cartography and literature, this term took on the meaning of anyplace beyond the known world at the time. Claudian, the Latin poet, proclaimed, “ratibusque impcrvia Thule” which means “where no ships can sail.”
The mythical island of Thule shows up with different variations in spelling over the years: Tile, Tyle, Tylen, and Thyle. This astronomy and geography manuscript from the mid 11th to 12th century shows a map of the world. In the lower right corner, the island of Tylen can be seen.
Marginalia from a manuscript from around the same period also contains a notation for “thule insula”.