Thousands of historical images taken by aircraft have now become part of Google Earth's historical image collection. Once you have loaded Google Earth, select
Historical Images under the
View Menu. (To update to the latest Google Earth version goto
http://www.google.com/earth/index.html.)
Travel to your selected destination. If there are historical images of that area, a clock will appear in the menu. Clicking on the clock will give you a timeline; the hash marks indicate the year that images are available. Clicking on the clock again will bring you back to present day.
