April 28
This day in history:
- 1991 – Space Shuttle Discovery launches on STS-39, the first unclassified shuttle mission for the United States Department of Defense.
- 1294 – Temür, grandson of Kublai, is elected Khagan of the Mongols with the reigning title Oljeitu.
- 1952 – Dwight D. Eisenhower resigns as Supreme Allied Commander of NATO in order to campaign in the 1952 United States presidential election.
- 1983 – The West German news magazine Stern begins publishing excerpts from the purported diaries of Adolf Hitler, later revealed to be forgeries.
Births:
- 1984 – Dmitri Torbinski, Russian footballer
- 1865 – Charles W. Woodworth, American entomologist and academic (d. 1940)
- 1900 – Heinrich Müller, German SS officer (d. 1945)
Deaths:
- 1945 – Benito Mussolini, Italian journalist and politician, 27th Prime Minister of Italy (b. 1883)
- 1978 – Mohammed Daoud Khan, Afghan commander and politician, 1st President of Afghanistan (b. 1909)
- 1841 – Peter Chanel, French priest, missionary, and martyr (b. 1803)
Holidays:
- National Heroes Day (Barbados)
- Sardinia Day (Sardinia)
- *Workers' Memorial Day and World Day for Safety and Health at Work (international)*
Random Article of the day:
Near Infrared Camera and Multi-Object Spectrometer
The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) is a scientific instrument for infrared astronomy, installed on the Hubble Space Telescope (HST), operating from 1997 to 1999, and from 2002 to 2008. Images produced by NICMOS contain data from the near-infrared part of the light spectrum.
NICMOS was conceived and designed by the NICMOS Instrument Definition Team centered at Steward Observatory, University of Arizona, USA. NICMOS is an imager and multi-object spectrometer built by Ball Aerospace & Technologies Corp. that allows the HST to observe infrared light, with wavelengths between 0.8 and 2.4 micrometers, providing imaging and slitless spectrophotometric capabilities. NICMOS contains three near-infrared detectors in three optical channels providing high (~ 0.1 arcsecond) resolution, coronagraphic and polarimetric imaging, and slitless spectroscopy in 11-, 19-, and 52-arcsecond square fields of view. Each optical channel contains a 256×256 pixel photodiode array of mercury cadmium telluride infrared detectors bonded to a sapphire substrate, read out in four independent 128×128 quadrants.
NICMOS last worked in 2008, and has been largely replaced by the infrared channel of Wide Field Camera 3 after its installation in 2009.