traverse-our-universe:“This is a small example from an ambitious all-sky photographic survey c
traverse-our-universe:“This is a small example from an ambitious all-sky photographic survey completed during the mid to late 20th century. Every piece of sky was photographed on large glass plates. This astrophotography provided a catalog for astronomers to use in seeking out targets and planning observations. It is also an archival snapshot of the entire sky. Over 1,000 of these photographic plates were later digitized into a database used to aim Hubble.” (from the book Hubble’s Universe: Greatest Discoveries and Latest Images) -- source link