Key Takeaways:
- Under the leadership of George Ellery Hale, the 100-inch mirror for Mount Wilson Observatory's telescope was ordered in 1906, with funding provided sequentially by businessman John Hooker and then Andrew Carnegie.
- The project encountered several delays, including dissatisfaction with the initial mirror completed in 1908 by French Plate Glass Companies, subsequent cracking during further attempts, and disruptions from World War I, until Hale approved the first mirror for grinding and polishing in 1910.
- After requiring road widening to transport its 9,000-pound mirror, the 100-inch Hooker Telescope achieved first light on November 1, 1917, initially providing distorted images of Jupiter before yielding a sharp view of Vega upon the mirror's cooling.
- The Hooker Telescope remained the largest in the world until 1948 and was instrumental in significant astronomical discoveries by prominent scientists including Edwin Hubble, Albert Michelson, and Harlow Shapley.
Under the leadership of George Ellery Hale, the mirror for Mount Wilson’s 100-inch scope was ordered in 1906. Businessman John Hooker initially covered the expenses; when he later withdrew his support, Andrew Carnegie would complete the funding. The project was delayed several times, at first by disappointment with the initial version of the mirror that the French Plate Glass Companies in St. Gobain, France, completed in 1908. Further attempts at the mirror were hindered by cracking and then by the outbreak of World War I until finally, in 1910, Hale determined that the first mirror could be used. The painstaking process of grinding and polishing the 9,000-pound piece began, as did the construction of the rest of the telescope and its dome.
As part what would be the largest telescope in the world at the time, the mirror was so gargantuan that the road up the observatory had to be widened before it could be transported. Finally, the 100-inch Hooker Telescope was fully assembled, and saw first light on Nov. 1, 1917. Though a first look at Jupiter was badly distorted by several overlapping images, by the early morning hours, once the mirror had cooled, Hale was able to see a sharp, focused image of Vega. The Hooker would be the largest telescope in the world until the construction of the Hale Telescope in 1948, and would famously be part of groundbreaking discoveries by Edwin Hubble, Albert Michelson, and Harlow Shapley, among others.
