general_fact: 303 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 303 is the number of bipartite graphs with 8 vertices.
trivia: 303 is an uninteresting number.
historical_date: October 29th is the day in 1991 that the American Galileo spacecraft makes its closest approach to 951 Gaspra, becoming the first probe to visit an asteroid.