How well do you know the night sky? OK, but how well can you identify famous sky objects in a very deep image? Either way, here is a test: see if you can find some well-known night-sky icons in a deep image filled with filaments of normally faint dust and gas. This image contains the Pleiades star cluster , Barnard's Loop , Orion Nebula , Aldebaran , Betelgeuse , Witch Head Nebula , Eridanus Loop , and the California Nebula . To find their real locations, here is an annotated image version . The reason this task might be difficult is similar to the reason it is initially hard to identify familiar constellations in a very dark sky : the tapestry of our night sky has an extremely deep hidden complexity . The featured composite reveals some of this complexity in a 16 hours of sky exposure in dark skies over Granada , Spain . from NASA https://ift.tt/d0wK8Hx