* Astronomy

A V-2 (V-2 42 configuration) was launched from White Sands LC33 on December 9, 1948
http://en.wikipedia.org/wiki/History_of_X-ray_astronomy#The_USA_V-2_period

Pioneer Venus 2 arrived at Venus in 1978
http://en.wikipedia.org/wiki/Pioneer_Venus_project

Adriaan Adriaanszoon, called Metius, (December 9, 1571 - September 6, 1635), was a Dutch geometer
http://en.wikipedia.org/wiki/Metius

Gemma Frisius (born Jemme Reinerszoon) (December 9, 1508-May 25, 1555), was a physician
http://en.wikipedia.org/wiki/Gemma_Frisius

Rear Admiral Grace Murray Hopper (December 9, 1906 - January 1, 1992) was an American computer scientist
http://en.wikipedia.org/wiki/Grace_Murray_Hopper

Henry Way Kendall (December 9, 1926 - February 15, 1999) was an American particle physicist
http://astronomy.activeboard.com/t46653795/henry-way-kendall-1926-1999/

Leo James Rainwater (December 9, 1917 - May 31, 1986) was an American physicist
http://en.wikipedia.org/wiki/James_Rainwater

Dr. Steven H. Pravdo (born 9 December 1951) is a Principal Scientist at Jet Propulsion Laboratory
http://astronomy.activeboard.com/t62986207/steven-h-pravdo/

Chester Moore Hall (9 December 1703 - 17 March 1771) was a British lawyer and inventor who produced the first achromatic lenses in 1729 or 1733
https://en.wikipedia.org/wiki/Chester_Moore_Hall

Henry Lee Giclas (December 9, 1910 - April 2, 2007) was an American astronomer.
https://en.wikipedia.org/wiki/Henry_L._Giclas

Robert A. Schommer (December 9, 1946 - December 12, 2001) was an American observational astronomer.
http://en.wikipedia.org/wiki/Robert_Schommer

NGC 613 was discovered by William Herschel on the 9th December 1798. 
http://astronomy.activeboard.com/t55847584/ngc-613/

NGC 957 was discovered by John Herschel on the 9th December 1831. 
http://astronomy.activeboard.com/t55848740/ngc-957/

NGC 1332 was discovered by William Herschel on the 9th December 1784. 
http://astronomy.activeboard.com/t55847640/ngc-1332/

NGC 1353 was discovered by William Herschel on the 9th December 1784.
http://astronomy.activeboard.com/t55847974/ngc-1353/

NGC 1401 was discovered by William Herschel on the 9th December 1784. 
http://astronomy.activeboard.com/t55848007/ngc-1401/

NGC 1426 was discovered by William Herschel on the 9th December 1784. 
http://astronomy.activeboard.com/t55848051/ngc-1426/

NGC 1439 was discovered by William Herschel on the 9th December 1784. 
http://astronomy.activeboard.com/t55848082/ngc-1439/

NGC 2527 was discovered by William Herschel on the 9th December 1784. 
http://astronomy.activeboard.com/t55848320/ngc-2527/

NGC 7826 was discovered by William Herschel on the 9th December 1784. 
http://astronomy.activeboard.com/t55848914/ngc-7826/

Halley's Comet aphelion on 9 December 2023
http://en.wikipedia.org/wiki/Halley%27s_Comet

The Great Comet of 1744 was independently sighted on December 9, 1743
http://en.wikipedia.org/wiki/Great_Comet_of_1744

Comet 3D/Biela approached within 0.0366 AU, 14.2 lunar distances, of Earth on 9th December 1805.
https://books.google.co.uk/books?id=5XXjVF8fuGkC&pg=PA4#v=onepage&q&f=false

On 9 December 1997, sensors aboard DOD satellites detected the impact of a meteoroid at 08:15:55 UTC roughly midway between Nuuk and Qaqortoq, Greenland. 
http://goes.gsfc.nasa.gov/text/9712.greenland/GREENLAND.METEOR.HTML

The Fireball of December 9, 1965
http://astronomy.activeboard.com/t55849267/december-9-1965-meteor/

The Kecksburg UFO incident occurred on December 9, 1965 
http://astronomy.activeboard.com/t14001096/kecksburg-ufo/