page_title: Mount Wilson Observatory
section_title: 100-inch Hooker telescope
hierarchical_section_title: Mount Wilson Observatory / 100-inch Hooker telescope
context_page_description: The Mount Wilson Observatory is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a 1,740-metre peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles.
  The observatory contains two historically important telescopes: the 100-inch Hooker telescope, which was the largest aperture telescope in the world from its completion in 1917 to 1949, and the 60-inch telescope which was the largest operational telescope in the world when it was completed in 1908. It also contains the Snow solar telescope completed in 1905, the 60 foot solar tower completed in 1908, the 150 foot solar tower completed in 1912, and the CHARA array, built by Georgia State University, which became fully operational in 2004 and was the largest optical interferometer in the world at its completion.
  Due to the inversion layer that traps smog over Los Angeles, Mount Wilson has steadier air than any other location in North America, making it ideal for astronomy and in particular for interferometry.
context_section_description: The 100-inch (2.5 m) Hooker telescope located at Mount Wilson Observatory, California, was completed in 1917, and was the world's largest telescope from 1917 to 1949. It is one of the most famous telescopes in observational astronomy of the 20th century.  It was used by Edwin Hubble to make observations with which he produced two fundamental results which changed the scientific view of the Universe. Using observations he made in 1922–1923, Hubble was able to prove that the Universe extends beyond the Milky Way galaxy, and that several nebulae were millions of light-years away.  He then showed that the universe was expanding.
caption: Hooker Telescope enclosure
exif: {"Image Make": "Apple", "Image Model": "iPod touch", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "11.4", "Image DateTime": "2018:06:30 15:38:47", "Image ExifOffset": "170", "EXIF ExposureTime": "1/2809", "EXIF FNumber": "12/5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "25", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2018:06:30 15:38:47", "EXIF DateTimeDigitized": "2018:06:30 15:38:47", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ShutterSpeedValue": "7263/634", "EXIF ApertureValue": "4845/1918", "EXIF BrightnessValue": "16795/1508", "EXIF ExposureBiasValue": "0", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash did not fire, auto mode", "EXIF FocalLength": "33/10", "EXIF SubjectArea": "[1631, 1223, 1795, 1077]", "EXIF SubSecTimeOriginal": "984", "EXIF SubSecTimeDigitized": "984", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "3056", "EXIF ExifImageLength": "2448", "EXIF SensingMethod": "One-chip color area", "EXIF SceneType": "Directly Photographed", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF FocalLengthIn35mmFilm": "31", "EXIF SceneCaptureType": "Standard", "EXIF LensSpecification": "[33/10, 33/10, 12/5, 12/5]", "EXIF LensMake": "Apple", "EXIF LensModel": "iPod touch back camera 3.3mm f/2.4"}