"Working with the U.S. Geological Survey (USGS), NASA and TIME, we're releasing more than a quarter-century of images of Earth taken from space, compiled for the first time into an interactive time-lapse experience. We believe this is the most comprehensive picture of our changing planet ever made available to the public."
The map data come from the government as part of the Landsat program, which has been capturing satellite photos of the world for four decades. The technology doesn't capture zoomed-in images of buildings, but it's detailed enough to show large, man-made structures such as roads. This allows us to see how the landscape has changed with growth.
Google's work with the imagery to create the Timelapse project is remarkable. The company pored over 2 million images more than 900 terabytes of data and published those in which cloud cover didn't obscure the ground. They did this for every year going back to 1984 and they covered the entire planet. See examples here.
In addition to specific examples published in animated GIFs, you can also explore the imagery in more of a traditional Google Maps interface. Check out deforestation in the Amazon, for example. Or the effect of coal mining in Wyoming. You can also search for specific locations near you.
If you're interested in cool imagery, check out these previous posts: