Those familiar with my Urando universe* will know that it features a planet populated by humans who were brought there by a mysterious alien civilization only known as the “angels”.
On a side note: I have completed a first draft of part one of The Urando Trilogy, “The Celestial Conspiracy”. I will soon start a throughout edit of this work, partially required by the ongoing Brexit saga. Also the upcoming US presidential elections will affect details of the story.
As stated above, the background of this series involves extraterrestrial intelligence interfering with human affairs over the span of at least dozens of thousands of years. This, of course, requires that those aliens can somehow observe both Earth and Urando from a safe distance.
Tech Times reports that according to scientist James Benford ET can use masqueraded co-orbital objects as a base to spy upon us. This is interesting because, as it mentioned in the article, this would allow any ET scientist to observe our world while residing in interstellar space.
On the backside, for those aliens, is that we might find their equipment if we would launch a mission to such co-orbital objects. And unless these are booby-trapped somehow, their creators cannot do much to prevent us for investigating those objects.
Back to the story. The use of masqueraded celestial objects to spy upon us, is interesting as a plot device.