The great wall of china

[The Rut]

How can the great wall of china be seen from space when at its widest it is no wider than a modern motorway, surely this must be just a myth that is taken as a fact.

[cupra]

You're right - it's another urban legend! Depending on the height of orbit, plenty of man-made structures can be seen - here's a photo from the Space Shuttle photography database

http://earth.jsc.nasa.gov/photoinfo.cgi?PHOTO=NM23
-762-210

[Quizmonster]

According to the NASA website, the current definition of where 'space' begins is..."the lowest altitude that permits a vehicle to orbit the earth without entering the earth's atmosphere. That altitude is approximately 100 km (62 miles)." So, space begins around 60 miles above the earth's surface. From that height, there are lots of man-made things which are visible, as the earlier answer says. Seeing the Great Wall from the MOON, however - which is what is usually claimed - is exactly as likely as seeing a schoolboy's 12-inch ruler if he held it aloft 400 miles away!

[PaulYukochan]

It is very wide if you turn it 90 degrees in either direction