Why is the Great Wall of China visible from space?

[seokjin]

I’ve heard this claim so many times, but is it really true that astronauts can see the Great Wall from space with the naked eye? If not, what makes something visible from space anyway?

 

[patoowardfan]

I’ve heard this claim so many times too! But from what I’ve read, astronauts can’t actually see the Great Wall from space with the naked eye. It’s too thin and blends in with the surroundings. What stands out more are things like city lights at night or huge areas like deserts and oceans. So, it’s not the wall, but bigger, brighter things that catch their attention!