Oct 20
1984
The Monterey Bay Aquarium opens
On this day in 1984, a former sardine factory on California’s historic Cannery Row began a remarkable new chapter: The Monterey Bay Aquarium opened its doors, transforming a site once devoted to processing fish into a place dedicated to understanding and protecting marine life.
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© Eric Kruszewski/Design Pics Editorial—Universal Images Group/Getty Images; Photo Illustration Encyclopædia Britannica, Inc.
Featured Event
© Michael Hynes
Opening of Sydney Opera House
Australia’s Sydney Opera House—designed by Danish architect Jørn Utzon, whose dynamic, imaginative, and problematic plan won an international competition in 1957—was opened by Queen Elizabeth II on this day in 1973.
Featured Biography
© Patrick Piel/Gamma Liaison
Christiane Nüsslein-Volhard, a German developmental geneticist who in 1995 was a corecipient of the Nobel Prize for Physiology or Medicine for research into early embryonic development, was born this day in 1942.
More on October 20
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2025
Demolition of the East Wing of the White House in Washington, D.C., began, in preparation for construction of a ballroom. [How often has the White House been renovated?]
NASA Goddard Space Flight Center
2020
NASA’s OSIRIS-REx collected a sample of rock and dust from the asteroid Bennu—the first time a U.S. spacecraft had done so. [Discover who’s competing in today’s space race.]
Andrew H. Walker/Getty Images Entertainment
2014
Fashion designer Oscar de la Renta—whose work, blending European luxury with American ease, helped define standards of elegant dressing among socialites, U.S. first ladies, and red-carpet celebrities—died in Connecticut. [Test your knowledge of fashion.]
MC2 Jesse Awalt/U.S. Department of Defense
2011
Muammar al-Qaddafi, the de facto leader of Libya since 1969, was killed by rebel forces following a revolt that ended his rule.
Image: Encyclopædia Britannica, Inc.
2002
Blue Stream, the deepest underwater pipeline in the world, opened in Turkey and was put in use for the transport of natural gas. [Sort fact from fiction in our quiz about oil and natural gas.]
Michael Ochs Archives/Getty Images
1977
A plane carrying the Southern rock band Lynyrd Skynyrd, known for such songs as Free Bird and Sweet Home Alabama, crashed in Gillsburg, Mississippi, killing singer Ronnie Van Zant and guitarist Steve Gaines, among others. [Take our rock and roll quiz.]
U.S. Department of Defense
1973
During the ongoing Watergate investigation, U.S. President Richard Nixon ordered special prosecutor Archibald Cox fired, resulting in the resignations of Attorney General Elliot Richardson and Deputy Attorney General William D. Ruckelshaus, both of whom refused to carry out his request; the events became known as the “Saturday Night Massacre” of Justice Department officials. [Read a first-person account of reporting Watergate as it happened.]
Michael Ochs Archives/Getty Images
1968
Former first lady Jacqueline Kennedy married Greek shipping magnate Aristotle Onassis. [How much do you know about U.S. first ladies?]
Library of Congress, Washington D.C. (neg. no. LC-USZ62-24155)
1964
Herbert Hoover, who was president of the United States from 1929 to 1933, died in New York City at age 90. [Learn how Hoover was elected—and what his reputation was before he took office.]
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1931
Baseball player Mickey Mantle—who was one of the game’s greatest players, known for his tremendous power as a switch-hitter—was born in Spavinaw, Oklahoma. [Test your knowledge of baseball.]
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1883
Peru and Chile signed the Treaty of Ancón, ending hostilities between the two countries in the War of the Pacific (1879–83). Under the treaty, Peru ceded Tarapacá province to Chile.
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1882
Actor Bela Lugosi—who was famous for his sinister portrayal of the elegantly mannered vampire Count Dracula—was born in Hungary. [Test your knowledge of scary movies.]
Image: Encyclopædia Britannica, Inc.
1822
The Congress of Verona, the last of the meetings held by the European powers in accordance with the terms of the Quadruple Alliance, opened in Verona, Italy. [Sort fact from fiction in our quiz about European history.]
Encyclopædia Britannica, Inc.
1803
The U.S. Senate, after due consideration and considerable oratory, ratified the Louisiana Purchase. [Learn how the Louisiana Purchase transformed America.]
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1740
Holy Roman Emperor Charles VI died, setting off the War of the Austrian Succession. [Test your knowledge of kings and emperors.]
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1600
The Battle of Sekigahara established the hegemony of the Tokugawa family in Japan. [Sort fact from fiction in our quiz about Japanese history.]
