Thirty-five nations, including the US and USSR, sign the Helsinki Final Act, easing Cold War tensions while enshrining human rights principles.

Workers finished hoisting the final antenna section atop Toronto's CN Tower by helicopter, completing the structure that would be the world's tallest for 32 years.

The Soviet probe Venera 9 transmitted the first images ever taken from the surface of another planet, revealing a rocky, sunlit Venusian landscape.

Eighteen-year-old Czech tennis star Martina Navratilova requests political asylum in the United States after competing at the U.S. Open.