This Day In History : December 18

1966 France

Discovery of Saturn's Moon Epimetheus

On December 18, 1966, the moon Epimetheus was discovered orbiting Saturn. It was initially observed by the astronomers Richard Walker, Audouin Dollfus, and Jean Texereau using the Pic du Midi Observatory in France. Epimetheus is notable for its unique co-orbital relationship with another moon, Janus, with which it shares its orbit.

Also on This Day in History December 18

Discover what happened on December 18 with HISTORY's summaries of major events, anniversaries,
famous births and notable deaths.

Births on This Day, December 18
  • 1890 Edwin Howard Armstrong

    American engineer who invented FM radio

  • 1856 Joseph John Thomson

    English physicist who discovered the electron, Nobel 1906

  • 1839 Théodule-Armand Ribot

    French psychologist who pioneered in experimental psychology

  • 1661 Christopher Polhem

    Swedish scientist and inventor

  • 1934 Boris Volynov

    Soviet cosmonaut (Soyuz 5, 21)

Deaths on This Day, December 18
  • 1934 Mark Felt

    American agent of the Federal Bureau of Investigation

  • 1995 Konrad Zuse

    German engineer and computing pioneer

  • 1915 Louise Blanchard Bethune

    1st American female professional architect

  • 1975 Theodosius Dobzhansky

    Russian-American genetist, biologist and author

  • 2006 Joseph Barbera

    American animator and cartoonist (Hanna-Barbera - Tom and Jerry, Flintstones)


World's First Communication Satellite Launched

On December 18, 1958, the world's first communication satellite, named SCORE (Signal Communication by Orbiting Relay Equipment), was launched into space by the United States. SCORE successfully broadcast a Christmas message from President Dwight D. Eisenhower back to Earth, marking a significant milestone in telecommunications history.

U.S. Abolishes Slavery with the 13th Amendment

On December 18, 1865, the United States officially abolished slavery with the ratification of the 13th Amendment to the Constitution. This historic amendment marked the end of legalized slavery in the United States, affirming that "Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction."

Discovery of Piltdown Man Skull

The discovery of the Piltdown Man skull was announced on December 18, 1912, in England. Found in Piltdown, East Sussex, the skull was initially thought to be a missing link between apes and humans. However, it was later revealed to be a hoax involving a combination of a human skull and an orangutan jawbone, making it one of the most famous scientific frauds in history.

NASA Launches Terra Platform with Earth Observation Instruments

On December 18, 1999, NASA launched the Terra platform into orbit, carrying five Earth observation instruments: ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), CERES (Clouds and the Earth's Radiant Energy System), MISR (Multi-angle Imaging SpectroRadiometer), MODIS (Moderate Resolution Imaging Spectroradiometer), and MOPITT (Measurements of Pollution in the Troposphere). These instruments have provided valuable data for studying Earth's climate, atmosphere, land surfaces, and ecosystems.
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