[thayne]

Just too faint for the naked eye to see is actually really, really bright compared to a lot of astronomical objects of interest. Enough that it could easily saturate a long exposure, and depending on how close it gets to the target, completely ruin the frame.

Fortunetely, that's less of a problem in the middle of the night, bu there is something else that worries me. What if far from sunrise or sunset the sattelite occludes an object you are observing, without leaving a trail? Hopefully, statistics would level that out, but with enough of these sattelites, the chances of that happening go up, and it may lead to incorrect results.