More Notable Events on July 20: 1994 O. J. Simpson offers $500,000 reward for evidence of ex-wife's klller 1988 Michael Dukakis selected Democratic presidential nominee 1984 Vanessa Williams is asked to resign as Miss America 1976 U.S. Viking 1 lands on Mars at Chryse Planitia, 1st Martian landing 1969 1st men on Moon, Neil Armstrong and Edwin Aldrin, Apollo 11