In a message dated 2/12/2007 12:51:22 PM Mountain Standard Time, 
[log in to unmask] writes:

> I recall Bill Rathje commenting that other than the Great Wall of China
> that the only human construct visible from space is the Fresh Kills
> landfill on Staten Island.
> 
> 
> http://www.nyc.gov/html/dcp/pdf/fkl/fien1.pdf
> 
> Silas Hurry
> 
> 
> >Because of the great distance and the resolution of the human eye, I
> >don't think any built structures are visible from the moon. These days,
> >the Great Walls of China (after all, there were a number of them) blend
> >into the surrounding scenery so well that you can't even spot them using
> >Google earth. What you can see from space (but usually no higher than
> >about 350 miles or so) are strip-mined areas, such as we have here in
> >Kentucky, and large swatches of deforestation, especially in the Amazon
> >River basin. At present, the most visible mark of humans to someone in
> >orbit (provided we discount the illuminations of cities at night) would
> >be a certain predilection for very large scale destruction. It's easier
> >to tell what we've destroyed (or economically altered, depending on your
> >point of view), as opposed to what we've built. I can only assume that
> >large-scale deforestations from the late 1800s and early 1900s would
> >also have been visible from space. That might be an interesting
> >historical archaeology topic - "Historic Instances of Large Scale
> >Disturbances Visible From Space, ca. 1800-1900".
> >
> >Daniel B. Davis
> >Archaeologist Coordinator
> >Kentucky Transportation Cabinet
> >Division of Environmental Analysis
> >200 Mero Street
> >Frankfort, KY 40622
> >(502) 564-7250
> 

Don't forget the Kennecott open pit copper mine near Salt Lake City - it 
definitely is mentioned on a regular basis - it is over a mile across.

Mike Polk
Sagebrush Consultants, L.L.C.
Ogden, Utah