You ll need to install the gnome task scheduler but all this requires is entering sudo apt-get install gnome-schedule in a Terminal window. When it s finished installing you ll be able to access the scheduler in Applications System Tools Schedule Tasks. Hit the “new” button and make the description whatever you want like “Moving Wallpaper”. Set a Rotating Picture of the Earth as Your Ubuntu WallpaperThis trick is fueled by the ever-useful wget command which will download a photo of the earth from die.net at a specified time interval. In the command box type in wget -r -N http static.die.net earth mercator 1600.jpg and set the default behavior to suppress output. Die.net uploads a new photo every 3 hours so I picked an interval of 6 hours to compromise my desire to have a semi-accurate view of the Earth at that time and my desire to not overflow Die.net s servers. You can specify a custom time period by clicking the edit button next to a time interval in the Advanced section. After you ve set it up hit the run button the one with the gears icon so it will download the first photo. Then right click on your desktop and hit Change Desktop Background. The photo will be stored in ~ static.die.net earth mercator on your hard drive so navigate there and choose 1600.jpg as your wallpaper. Now it should automatically update at the time interval you specified in the last step giving you a cool picture of the world s sunlight at that time of day.

via Set a Rotating Picture of the Earth as Your Ubuntu Wallpaper.