Keeping space-myths aside, many of us even remember reading in our school textbooks about the Great Wall of China being the ONLY man-made structure that?s visible on earth from outer space! Some have even mentioned about this gigantic marvel being visible from the moon!
With the sole intent of ?clearing the air? as far as such theories are concerned, even NASA (National Aeronautics and Space Administration) has dedicated an exclusive page on its official website, explaining why these beliefs are part of a space misconception! So here?s a look at some hardcore facts to give you a glimpse of reality:-
If you rely on the unaided eye, the Great Wall of China is not visible to astronauts even from the Lower Earth Orbit! In fact, no man-made structure on earth is visible from outer space when viewed using your naked eye.
What?s actually visible to astronauts are the natural contours and landscape of the earth, along with the blue hues of the oceans, and although the Great Wall is pretty huge (roughly measures 5500 miles in length), it?s definitely not wide enough to be visible without a visual aid!
In 2003, when Yang Liwei , the first Chinese Astronaut forayed into outer space, it?s obvious that the first glimpse that he strived to get from his shuttle window was that of the Great Wall! But he clearly stated that the structure was not visible to him. Even when he took an aerial photograph using a 180 mm zoom lens, he couldn?t identify the wall on it. Talk about hearing it from the horse?s mouth!
On the contrary, the Ancient Pyramids of Giza in Egypt, the Toyota Center in Texas and even well-lit cities have been visibly demarcated in radar images produced by satellites and also manually!
It needs to be remembered that what?s visible and what?s not, specifically depends upon the ongoing weather and atmospheric condition, the camera resolution, the shape, age and illumination of the structure and so on!