Why can’t we see Buildings like skyscrapers from space?
In: Physics
Skyscrapers are really tall buildings; their size is in the “up” direction. Space is up. When someone in space looks down on a skyscraper, it doesn’t look bigger than any other building. Most buildings are just too small to see from the distance of someone in space.
Space starts at 100 km (62 miles) above the ground.
How much detail do you think you can see from an hours drive away? On a clear day you might be able to see a mountain in the distance, but not individual buildings.
Of course if you have the right tools you can totally see small stuff from far away, but not with the naked eye.
Astronauts on the ISS are about 400 km up above the ground. The detail you can see at that distance with the naked eye is rather limited.
Spy satellites in sun synchronous orbits may be as low as 274 km and while none of the agencies that have them are keen on sharing any details of their capabilities, I guess we can safely assume that they can do far better than just seeing big skyscrapers. (You would have to ask the NRO or the CIA for details.)
You *can* make out a few man-made structures from space, though height doesn’t help much.
https://www.mentalfloss.com/article/57961/5-man-made-things-you-can-see-space-plus-one-you-really-cant
Orbits are about 400 km high or 250 miles something need to have a very large area and not height to be spotted from that distance.
It’s the same reason why you can’t properly see a needle pointing directly at your eye. For your eye, it is only a dot (the tip). There may be a long and slander body behind that tip, but it is all hidden from your view behind the tip.
Now, the top of the buildings are the tip of the needle, and they are pointing directly at the person looking down from space. The more directly below the building shall be beneath the observer, the smaller the profile of the building shall be, it doesn’t matter how tall the building is.
Also things appear to your eye to get smaller the further you are away from them. Orbits are several hundred miles up… anything you can see from 100 miles away even if it has a very large area is going to appear very small.
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