IAU definition of planet who had theorized on the existence of the large trans-Neptunian object Planet X, and Tombaugh been searching for Planet X when he found Pluto. Almost immediately after its discovery, however, astronomers questioned whether Pluto could be Planet X. Willy Ley wrote a column in 1956 titled "The Demotion of Pluto", stating that it "simply failed to live up to the advance publicity it received as 'Planet X' before its discovery. It has been a disappointment all along, for it did not turn out to be what one could reasonably have expected". In 1978, Pluto's moon Charon was discovered. By measuring
Sailor Pluto doesn't display any personality traits associated with Scorpios despite being born under the sign; it seems to have been picked solely for its astrological significance. Also, according to Naoko Takeuchi's notes in the various artbooks, she mentions that "Setsuna wears hotpants as well at home, but basically she also likes long skirts" and that she believes "Setsuna should forever wear white clothes". The kanji of Setsuna's surname translates as and . Together, they constitute most of the name of the dwarf planet Pluto in Japanese: . Her given name is in hiragana and so its meaning is not inherent, but