In the times before automated sky surveys with space observatories such as ESAs Gaia, lots of stars, galaxies, and nebulae were discovered by ways of big photographic surveys.Astronomers used the most advanced large telescopes of the time to produce hundreds of photos, covering a location of the sky. They later on studied the resulting photos, trying to catalog all the new astronomical objects revealed.Advances in Astronomical TechniquesIn the 1970s a new telescope at ESOs La Silla center in Chile carried out such a survey of the southern sky, which still had actually not been taken a look at in as much depth as the sky in the north. Numerous were new to astronomy.Evolution of Sky SurveyingAstronomical sky surveying has actually because transitioned through digital, computer-aided studies such as the Sloan Digital Sky Survey and the Legacy Surveys, to surveys made by area telescopes consisting of Gaia and the Wide-Field Infrared Survey Explorer.Even so, photographic sky surveys contributed immensely to astronomical knowledge for decades, and the archives of glass plates serve as an essential historical referral for large swathes of the sky.