Earth Explorer is a useful application very similar to Goggle Earth that allows you explore the whole world. It provides satellite, topographic, and blend views of any part of the world. You can easily know basic information about any country or city of the world by simply looking for it with its search tool. You can even import your own data to the map and place marks and paths. You can easily calculate distances with a ruler that shows you the kilometers between two different locations. It even has the ability to show political boundaries, longitude-latitude grids, geographical features like rivers, streams, etc., detailed information on earthquakes, among other useful things. What is great is that all the maps can be saved and printed for educational or informational purposes.
What is more, you can connect the program to a GPS, show GPS track, and report GPS location to manager server periodically when the GPS is connected.
Unfortunately, the zoom is not that powerful as that of Google Earth: since it only has 30m/pixel resolution you won't be able to see the cities per se.
In short, Earth Explorer is a wonderful tool to explore the world from your pc.