THIS is apropos of Dr Irfan Zafar’s letter ‘Believe it or not’ (Jan 17). He compared the queues of vehicles waiting for CNG with the Great Wall of China and how both were visible from the moon.

Although somewhat suffering from the shortage of CNG in Pakistan myself, I enjoyed the little joke about the long lines.

However, the record must be set straight. Regardless of what “Ripley’s ‘Believe it or not’” and “Richard Halliburton’s ‘Second Book of Marvels’” may state, Nasa has the following to say about the Great Wall of China’s visibility from the moon:

“It has become a space-based myth. The Great Wall of China, frequently billed as the only man-made object visible from space, generally isn’t, at least to the unaided eye in low Earth orbit. It certainly isn’t visible from the moon.”

Nasa’s website further states: “The visible wall theory was shaken after China’s own astronaut, Yang Liwei, said he couldn’t see the historic structure. There was even talk about rewriting textbooks that espouse the theory, a formidable task in the Earth’s most populous nation.”

ADIL MULKI Karachi