TASK DEFINITION: You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.
PROBLEM: Category: SPACE MISSIONS 
Clue: The New Horizons mission was launched to explore this planet before it was downgraded to a dwarf

SOLUTION: pluto

PROBLEM: Category: 12-LETTER WORDS 
Clue: Meaning a beginning, it's also a school graduation ceremony

SOLUTION: commencement

PROBLEM: Category: 12-LETTER WORDS 
Clue: From the Latin for "bend the knees", not the cry of a ski instructor, but the act of showing reverence

SOLUTION:
genuflection