In October, 2004, Google acquired the Keyhole Corporation, which has offered, since 2001, a $69 program to download and view satellite images. It wasn't big news until the summer of 2005, when Google announced that it would offer a new version called Google Earth–for free! Suddenly millions the world over were able to soar over Mother Earth, zoom down on Zanzibar, hover over the swimming pool of their neighbor's house in Rio de Janeiro, count the cars on the street parked next to the Kremlin in Moscow or fly like a stratospheric bird over the Himalayas.

The "wow " factor of Google Earth is off the charts and will certainly change the way the next generation thinks about the world. There it is, right in front of you, one world, one family, on screen.

What you can see: During the cold war, between 1963 and 1967, the US Corona series KH (Keyhole) spy satellites brought home hundreds of thousands of hi-resolution images that were declassified in 1996. Hence the name, "Keyhole." But only a small percentage of KH hi-res images comprise Google Earth's patchwork of images from different satellites using different technologies. A large percentage is from older, lower resolution Earthsat environmental studies images and more recent sources. Any given view may be a composite of several images, some 30 years old. So, lower your expectations if you are looking for real-time and universal super resolution. You get hi-res in San Francisco, but won't find anything like it for Angkor Wat in Cambodia. And, as you would expect, views are all from the top, and the 3D views are rendered, not real images.

Google-powered: Google brings unprecedented tools for educators, researchers, travelers, students and business. Create, save and e-mail placemarks and tours, and follow intricate tours already prepared by others. For a price you can get GPS device support, drawing tools and better printing. For sheer mind-expanding fun, this blogger, Kanaka Ravi Kumar, says it well: "I'd like to congratulate all technicians behind this awesome creation. I'm very much thankful to them. Opening this site is an odyssey, a never-ending adventure."

http:/www.earth.google.com [http:/www.earth.google.com]