Written by Robert
Google Earth has a great feature where you can go back in time and look at previous satellite images. In most metropolitan areas, the images are fairly good quality until about the year 2000 and then they get a little rough. In most populated areas, you can get images back to the mid nineties. In some areas, they've augmented the data with aerial surveys. In those cases you can get data much father back. For instance, at my first home in San Francisco, you can go back to 1938, In downtown Portland, the aerial survey images go back to 1952.
Lets take a look at some satellite imagery of the going queen and see what useless information we can glean from them.