Astronomers Michel Mayor and Didier Queloz reported the discovery of a planet orbiting 51 Pegasi (depicted) as the first known exoplanet around a main-sequence star.
About 200 members of the San Francisco Police Department instigated a police riot in the Castro following a peaceful protest held by the political group ACT UP.
Egyptian president Anwar Sadat (pictured) was assassinated while attending a parade in Cairo to mark the eighth anniversary of the Crossing of the Bar Lev Line at the start of the 1973 Arab-Israeli War.
Two bombs placed by the CIA-linked Cuban dissident group Coordination of United Revolutionary Organizations exploded on Cubana Flight 455, killing all 73 people aboard.
The Egyptian Armed Forces crossed the Suez Canal (pictured) to attack occupying Israeli forces at the Bar Lev Line in the Sinai Peninsula, beginning the Yom Kippur War.