A few days ago, I was speaking to a friend about the effect that building a real-life Death Star would have on the earth. Sure, we don't exactly have the engineering or astronomical knowledge to make that a reality, but it's interesting to think about the effects of such a massive change. If we assume that the Death Star has properties nearly identical to our own moon in terms of mass and radius, we would definitely expect a change in tides due to its gravitational pull on the earth. Also, if the Death Star were orbiting our earth as our moon does, we would either have twice as many eclipses due to the two "moons", or the two would end up crashing into each other. These are things to consider when working on such a massive scale. The bigger a change you make, the more it affects the smaller details.
Also, the government told us no.