UNESCO inscribed the Maya city of Chichen Itza, home to the great pyramid Kukulkan, as a World Heritage Site.

East German border guards shot and killed a would-be escapee near the Berlin Wall, one of the last such deaths before the Wall's fall the following year.

A U.S. appeals court ruled that Apple's operating system code was protected by copyright, a major precedent-setting decision against clone makers like Franklin Computer.

The United Nations adopted the Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, reshaping international drug enforcement law.

Aboard the Mir space station, cosmonauts continued a research mission studying long-duration spaceflight effects, part of the growing Soviet effort to master orbital endurance.

The USS Vincennes fired two missiles at an Iranian passenger jet over the Persian Gulf, mistaking it for a hostile aircraft and killing all 290 people aboard.

Chile's 1988 plebiscite result was confirmed: voters had rejected another eight-year term for dictator Augusto Pinochet, forcing a democratic transition.

F. Ross Johnson proposed a management-led leveraged buyout of RJR Nabisco, igniting the largest and most cutthroat corporate takeover battle of the 1980s.

The Morris Worm, released the previous day, spreads across thousands of computers, forcing researchers to disconnect systems and prompting the first major CFAA prosecution.

The Soviet space shuttle Buran launches unmanned, orbits Earth twice, and lands automatically—its only flight before the program's cancellation.

NSFNET established one of the earliest high-speed transatlantic network connections linking American research networks to European counterparts, a foundational step toward the modern global internet.

The World Health Organization observed the first World AIDS Day, launching an annual global campaign of awareness during the height of the epidemic's terror and stigma.

Soviet Soyuz TM-7 carrying French astronaut Jean-Loup Chrétien docked with the Mir space station, deepening Cold War-era space cooperation.

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Chile's electoral tribunal certified the 'No' victory from October's plebiscite, forcing General Augusto Pinochet to schedule democratic elections and end his dictatorship.

A terrorist bomb hidden in luggage detonated aboard Pan Am Flight 103, killing all 259 aboard and 11 people on the ground in Lockerbie, Scotland.