Discovered Appeared Not observed Appeared before discovery Not observed before discovery Returns in the future
2039 July 23 28P2021 Mar. 11 28P2002 Dec. 27 28P1984 Oct. 8 28P1966 Dec. 9 28P1948 Dec. 15 28P/1931 S11931 Apr. 30 28P/1913 R21913 Aug. 16