ET Bases Found On Saturn Moon In HD Photo, NASA Site! March 2017, Video, UFO Sighting News.

Date of discovery: March 2017
Location of discovery: Saturn Moon Enceladus
Source: http://photojournal.jpl.nasa.gov/catalog/PIA11124

These structures are hidden in the canyons of the moon. The cameras used by NASA for these space missions are some of the newest and most high tech innovations in the world, so you can be that there are no mistakes or glitches in these photos. NASA takes these photos for scientific exploration and studies, so glitches are something that NASA cannot afford if they want to keep up the publics trust. The structure here are layers upon layers, each different shade of black is a whole new layer (floors) of the structures that were made. Why hide them? Well, most the structure is below the ground and if you only have a few exits and entrances to go underground, you sure as hell don't want them found and destroyed by your enemies. So, aliens who live virtually forever want to up the odds of survival by camouflaging themselves, their ships and their structures. 
Scott C. Waring