Myth 1 of 10
1. Myth: the Great Wall of China can be seen from space
The Great Wall is enormous in length, but narrow: it is generally less than 10 metres wide. From the Moon, no human construction is visible to the naked eye, and even from low orbit the wall barely stands out.
Long, but too thin
Adding up all the sections built in different periods, the wall exceeds 20,000 kilometres. The problem with seeing it from afar is not its length but its width, similar to that of a street, and its colour, very close to that of the earth and stones around it.
The Moon is about 384,000 kilometres from Earth. From that distance, continents, oceans and clouds are visible, but no human work. It would be like trying to see a hair from more than 3 kilometres away.
Astronauts in orbit are much closer, a few hundred kilometres away. Even so, the first Chinese astronaut, Yang Liwei, said in 2003 that he could not see the wall. Photos taken from orbit with long-range lenses can capture it, but to the naked eye it is very hard to distinguish.
From space, what most reveals human presence are the city lights at night, large farmland areas and reservoirs. The myth of the wall is old: it circulated in books and magazines long before anyone went into space.
Did you know? The wall is not a single wall. It is a series of walls, trenches and natural barriers, built and rebuilt by different dynasties over more than 2,000 years.
About this list: these are 10 widely repeated myths, one per page, with what is actually known about each and an extra detail in the "Did you know?" box. The sources are at the end of the list.
