Google Earth just keeps getting more powerful with its awesomeness. Google Earth Historical Images is now in place. Previously, a snapshot of a location was all that was available to users. Google Historical Imagery now lets viewers “go back in time” to view images. Over time, this unique feature will make it possible to move back and forth over time to see how an area has changed.
For example, fly south of San Francisco in Google Earth and turn on the “clock” slider in the tool bar. Watch how fertile farmland changes into Silicon Valley.