system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars Episode IV] „That‘s no moon, that‘s a space station“ there‘s absolutely nothing nearby to give you a size relation of how big it really is. How did they know it from that distance then?
gpt
It looked like Han was looking at readouts from the Falcon when he mentioned it looked like a small moon.  I’m guessing the Falcon had something onboard to give relative size of incoming objects (a necessity for a starship.).  However, Obi-Wan could feel the millions of lives and weight of the dark side inside of the “moon” and correctly interpreted it to instead be a massive space station.