August 20th, 1858: Charles Darwin first published his theory of evolution through natural selection in The Journal of the Proceedings of the Linnean Society of London.

August 20th, 1882: Tchaikovsky’s 1812 Overture debuted in Moscow, Russia.

August 20th, 1975: NASA launched the Viking 1 planetary probe toward Mars.

August 20th, 1977: NASA launched the Voyager 2 spacecraft towards the outer solar system.

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Boxing promoter Don King turns 89 years old.

Singer Robert Plant turns 72 years old.

Actor John Noble turns 72 years old.

Weatherman Al Roker turns 66 years old.

Actor Don Stark turns 66 years old.

Actress Joan Allen turns 64 years old.

Director David O. Russell turns 62 years old.

Actor James Marsters turns 58 years old.

Rapper KRS-One turns 55 years old.

Singer Fred Durst turns 50 years old.

Actor Jonathan Ke Quan turns 49 years old.

Actress Amy Adams turns 46 years old.

Actor Misha Collins turns 46 years old.

Actor Ben Barnes turns 39 years old.

Actor Andrew Garfield turns 37 years old.

Singer Demi Lovato turns 28 years old.

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Thursday, August 20th is National Radio Day.