* Astronomy

On 6 May, 2000, the Aldershot Observatory was opened to the public for the first time
http://en.wikipedia.org/wiki/Aldershot_Observatory#Use

The Eiffel Tower was officially opened to the public in 1889.
http://en.wikipedia.org/wiki/Eiffel_Tower

The 1976 Friuli earthquake took place in northeast Italy on Thursday, May 6, 1976. 
http://en.wikipedia.org/wiki/1976_Friuli_earthquake

Crazy Horse surrenders to General Crook at Red Cloud Agency on May 6, 1877
https://en.wikipedia.org/wiki/Crazy_Horse#/media/File:Crazy_horse_c1877.jpg

IAU Working Group on Star Names (WGSN) were approved by the IAU Executive Committee at the EC98 meeting 6 May 2016
http://www.pas.rochester.edu/~emamajek/WGSN/WGSN_bulletin1.pdf (PDF)

David Cornell Leestma (born May 6, 1949) is a former American astronaut 
http://en.wikipedia.org/wiki/David_Leestma

Donald Alan Thomas (born May 6, 1955) is an American engineer and a former NASA astronaut.
http://en.wikipedia.org/wiki/Donald_A._Thomas

Chiaki Mukai (born May 6, 1952) is a Japanese doctor, and JAXA astronaut. 
http://en.wikipedia.org/wiki/Chiaki_Mukai

Aleksandr Aleksandrovich Skvortsov is a Russian cosmonaut. 
http://en.wikipedia.org/wiki/Aleksandr_Aleksandrovich_Skvortsov

Robert Edwin Peary, Sr. (May 6, 1856 - February 20, 1920) was an American explorer
http://en.wikipedia.org/wiki/Robert_Edwin_Peary

Grove Karl Gilbert (May 6, 1843 - May 1, 1918) was an American geologist.
https://en.wikipedia.org/wiki/Grove_Karl_Gilbert

Buddha's Birthday
http://en.wikipedia.org/wiki/Buddha%27s_Birthday

André Weil (6 May 1906 - 6 August 1998) was an influential mathematician of the 20th century
http://en.wikipedia.org/wiki/Andr%C3%A9_Weil

Robert Henry Dicke (May 6, 1916 - March 4, 1997) was an American physicist 
http://en.wikipedia.org/wiki/Robert_H._Dicke

Knut Jørgen Røed Odegaard (born 6 May 1966) is a Norwegian astronomer
http://en.wikipedia.org/wiki/Knut_J%C3%B8rgen_R%C3%B8ed_%C3%98degaard

Anlaug Amanda Djupvik is a Norwegian astronomer.
http://en.wikipedia.org/wiki/Anlaug_Amanda_Djupvik

Jana Tichá (born 1965) is a Czech astronomer. 
http://en.wikipedia.org/wiki/Jana_Tich%C3%A1

Eugeniusz Rybka (May 6, 1898 - December 8, 1988), was a Polish astronomer
http://en.wikipedia.org/wiki/Eugeniusz_Rybka

Carl William Hergenrother (born 1973) is an American astronomer
https://en.wikipedia.org/wiki/Carl_W._Hergenrother

Willem de Sitter (6 May 1872 - 20 November 1934) was a Dutch mathematician, physicist and astronomer.
http://en.wikipedia.org/wiki/Willem_de_Sitter

'Observations on the Two Lately Discovered Celestial Bodies' by William Herschel
http://www.jstor.org/sici?sici=0261-0523%281802%2992%3C213%3AOOTTLD%3E2.0.CO%3B2-R

Asteroid (417) Suevia was discovered by Max Wolf on May 6, 1896 in Heidelberg
http://en.wikipedia.org/wiki/417_Suevia

Eta Aquarids meteor shower
http://astronomy.activeboard.com/t2856244/eta-aquarids-meteor-shower/