Xearth is a favorite of mine in the ham shack. It displays an image of the earth, as seen from your favorite vantage point in space as your PC’s wallpaper.
Xearth updates the displayed image every five minutes. The time between updates as well as many parameters can be changed using the settings. There are a variety of options you can set, each found in individual tabs like image, viewpoint, sun, labels, display, time, shading, dots, and Earthquakes. It’s great for always knowing where the greyline is in the world.
Download Xearth here
The projection can be orthographic, mercator, or cylindrical.