They can only flash when they are in sunlight. So the middle of the night (except at the highest latitudes during summer) will always be safe from Iridiums, even uncontrolled ones. Then you just have to worry about bad weather, light pollution, meteors, and auroral displays messing up your beautiful astrophotos. PS: I'm planning on trying to observe the upcoming total solar eclipse from "Dillingen" in Bavaria. I thought since that's where my last name comes from, and it's almost on the center line, I just had to go there for it. However it is too small to be listed in any of the NASA prediction tables. Is there anyone that could calculate local circumstances for the eclipse given a latitude, longitude, and elevation? I'd be most grateful.