There's a myth the Great Wall of China is the only human-built object visible from space. It can even be seen from the moon, according to the legend.
Cosmonaut Oleg Artemyev of Russian space agency Roscosmos is pretty sure he photographed the epic structure from space, but that doesn't mean it's easy to spot from orbit.
Artemyev posted a photo of China as seen from the ISS on Sunday. "The @Space_Station flies over China. @Astro_Alex and I think that in this photo we can see the Great Wall of China. I've been looking for it for a long time!" he wrote.
Artemyev references his International Space Station crewmate Alexander Gerst, a European Space Agency astronaut. They both think they can see the wall in the image, though it's hard to tell which of the many lines across the landscape it might be.
If the Great Wall is indeed in the image, then the ISS crew can see it from space, though they spotted it with the help of a camera.
NASA says the wall generally isn't visible to the unaided eye from low Earth orbit. Though the wall spans thousands of miles, it isn't very wide.
"In fact, it is very, very difficult to distinguish the Great Wall of China in astronaut photography, because the materials that were used in the wall are similar in color and texture to the materials of the land surrounding the wall -- the dirt," NASA scientist Kamlesh Lulla said in 2005.
And how about the claim that you can see the Great Wall from the moon? Not a chance. Astronauts who visited our lunar neighbor said no man-made objects on Earth are visible from that distance at all.
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