You would think that it would be easy to spot a cosmic structure as enormous as a supercluster holding legions of galaxies, but not so -- the Milky Way can hide all kinds of objects, usually due to dust and stars obscuring the view. If you need proof, you just need to ask the astronomers who have discovered the Vela supercluster, a giant collection of galaxies about 800 million light years away (shown as "VSC" above). They only detected it by making "thousands" of spectroscopic studies of partially obscured galaxies -- it was hidden on the far side of the Milky Way.