Discovered Appeared Not observed Appeared before discovery Not observed before discovery Returns in the future
2028 Mar. 15 59P2018 Sept. 16 59P2009 Mar. 7 59P1999 Sept.16 59P1990 Nov. 22 59P1981 Nov. 30 59P/1971 O11972 Nov. 28 59P/1963 Q11963 Dec. 7