July 20, 1976. The spacecraft Viking 1 landed on Mars and was the first spacecraft to accomplish this mission. It was part of the Viking project, created by the National Aeronautics and Space Administration (NASA), which consisted in launching two spacecraft to Mars, Viking 1 and Viking 2, named for the fearless Nordic explorers of Earth. The first one was launched on August 20, 1975 and took 11 months to safely arrive and land on the red planet. It was soon followed by its twin, Viking 2, which was launched one month later and landed on September 3, 1976. The primary mission of Viking 1 was to discover if there was life on Mars, but the spacecraft only recovered inconclusive results. The spacecraft was designed to function for 90 days but it continued to collect data for six years and the mission ended in 1982.
Also on July 20: Tekle Giyorgis I begins his first of five reigns as Emperor of Ethiopia (1799); Citizens of Bogotá, New Granada declare independence from Spain (1810); British Columbia joins the confederation of Canada (1871); Police in Minneapolis fire upon striking truck drivers during the Minneapolis Teamsters Strike of 1934, killing two and wounding 67 (1934); Adolf Hitler survives an assassination attempt led by German Army Colonel Claus von Stauffenberg (1944); Harry Gold pleads guilty to spying for the Soviet Union by passing secrets from atomic scientist Klaus Fuchs (1950); King Abdullah I of Jordan is assassinated by a Palestinian while attending Friday prayers in Jerusalem (1951); The Central Intelligence Agency releases documents under the Freedom of Information Act revealing it had engaged in mind control experiments (1977); The Provisional IRA detonates two bombs in Hyde Park and Regents Park in central London, killing eight soldiers and injuring 47 people (1982); James Eagan Holmes opened fired in a midnight showing of The Dark Knight Rises killing 12 people and injuring 58.
Born on July 20: Alexander the Great (356 BC); Petrarch (1304); Richard Owen (1804); Gregor Mendel (1822); Elliot Richardson (1920); Dick Giordano (1932); Natalie Wood (1938); Wendy Richard (1943); Larry Craig (1945); Jay Jay French (1954); Paul Cook (1956); Chris Cornell (1964); Sandra Oh (1971); Vitamin C (1972).