BINGO!
"There are a few most likely reasons for this.
1- No high resolution imagery has been taken of the area in question. First of all, satellites have different quality capabilities. Also, the companies that take the images are not going to take and process high resolution images of areas unless they believe enough people/companies will want to buy them.
2- High resolution images were taken of an area but came out poorly due to cloud cover. (if you ever turn on GE's weather cloud layer, you'll see that on any given day, a lot of the earth is covered by clouds.)
3-High resolution images of an area exist but whatever company or entity owns them wants too much money from Google to license them. You have to keep in mind that GE is provided free by Google to most users.
Also, the very clear/close pictures that you see of certain areas are usually shot from airplanes, not satellites, as a special purchase."
http://groups.google...ors/Pq8L-6SbRvE