Objects visible from space

Man-made structures visible from earth orbit without mechanical aids such as a camera or binoculars include highways, dams, and cities. The most commonly cited example, the Great Wall of China is not the easiest one to see.

Cities are easily distinguishable from surrounding countryside by both shuttle astronauts in an Earth orbit 135 miles (217 kilometers) high. They are just as visible on the space station which is in a higher orbit, circling the planet at 250 miles (400 kilometers). Using binoculars, the astronauts can see roads, airports, dams and even large vehicles. Harbors and even large ships and tankers can be seen on the oceans.

The concept has entered popular culture as a meme, metaphor, urban legend, and proverb, that certain constructed objects or effects are so large as to be visible from outer space. For example, a giant beaver dam in Canada was described as "so large it is visible from outer space."

Cities
"The naked eye can tell the difference between cities and countryside from space."

The Great Wall of China
The Great Wall of China is, proverbially, the man-made object most often cited as being visible from outer space.

Other buildings and man-made objects
The "People's House" in Bucharest, Romania is the second largest building, after Pentagon, and has been cited as being visible from space.

A giant beaver dam discovered in Canada in early 2010 was described as being visible from space.

In popular culture
The meme, that some man-made objects are visible from outer space, has gotten into popular culture, often in the form of jokes. For example, Chuck Norris' roundhouse kick is allegedly so powerful, that it can be seen from outer space.