The thread below reminds of something from last night. I was watching an episode of The Orville, where the ship "suddenly" encountered another, massive ship from 450,000 km. That made me think about just how far that distance is, and how surprising that such a massive ship (it contained it's own full ecosystem, it was that big) wouldn't be detected until it was that close; it really broke the immersion for me. For reference, that's similar to the distance from the earth to the moon (average ~385,000 km).