What is the only man-made object on Earth visible from space?

Answer 1

"The Great Wall of China" is often cited as being visible from space. As an experiment, go on Google Earth or similar and try and find it at a reasonable satellite height! The "invisibility" is due to the aspect ratio of the structure - it would be long enough to see if it were wide enough. As it is, the arc covered by the width of the wall is too small to be picked up by your eyes.

I suspect some composite structures like cities would be visible at night from their lights.

Recent observations by astronauts indicate that the oil sands operations in Northern Alberta are visible from space.

Answer 2

The Great Wall of China is often cited as the only man-made structure visible from space with the naked eye, but this is a common misconception. In reality, the Great Wall is not easily visible from space without aid. The International Space Station, which orbits relatively close to the Earth, can only see large cities and human-made structures, like highways, not individual walls or specific landmarks.

Answer 3

The Great Wall of China is said to be able to be seen from low earth orbit but this is disputed by most astronauts.

Answer 4

The Great Wall of China