[ExI] Fermi question

[Kelly Anderson]

On Thu, Dec 22, 2011 at 5:49 AM, Ben Zaiboc <bbenzai at yahoo.com> wrote:
> Stefano Vaj <stefano.vaj at gmail.com> wrote:
>
>> I was thinking that after all from outer space the Chinese
>> Wall emains one
>> of the most obvious man-made structures ...
>
> Urban Myth alert!
>
> The idea of the Great Wall of China being visible from space pre-dates space travel.  It was /expected/ to be visible from space, but in fact isn't.
>
> It's too similar to its surroundings to stand out, which is why far smaller structures are visible from orbit, but the wall isn't.  Apparently, from the Moon, absolutely nothing man-made is visible on the earth.
>

Can't you see the big lighted cities at night from the moon??? Seems
like seeing LA all lighted up wouldn't be that hard. Of course that
isn't really a "structure"...

-Kelly