Ohhhh - about 93 million miles (Further at night)Originally Posted by mk10
More down to Earth - as an example of distant viewing of city scapes I have seen Boston downtown from Wachusett at about 45 miles distant. It was a fairly clear November day and the taller buildings could be discerned with the naked eye.
Other than the curvature issue the biggest handicap to distant views is moisture in the atmosphere. Clear, cold winter days are best.
This thread has wandered some, but still very interesting.