Examine source code of Sunset Orbit - Animated

{
  "theme": {
    "images": {
      "theme_frame": "FirefoxPersona-BLZ-Sunset-Orbit-Animated-header3.png"
    },
    "colors": {
      "frame": "#2000a0",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Sunset Orbit - Animated",
  "manifest_version": 2,
  "description": "To rate or comment, login here:\n<a href=\"https://addons.mozilla.org/en-US/firefox/addon/sunset-orbit-animated/#id=373957\" rel=\"nofollow\">https://addons.mozilla.org/en-US/firefox/addon/sunset-orbit-animated/#id=373957</a> \nSee all my personas here:\n<a href=\"https://addons.mozilla.org/en-US/firefox/collections/BrianZ/personas/\" rel=\"nofollow\">https://addons.mozilla.org/en-US/firefox/collections/BrianZ/personas/</a> \nThis aPNG file has 44 layers:  a non-animated preview layer + background layer + 42 planet layers at 62ms each = 16 fps.  Smallest and largest planet sizes where chosen arbitrarily at 20 and 80 pixels, all centered on one plane of view, with changing size and position used to create the illusion of circular motion in space.  Intermediates are positioned at every 5 degrees of circular motion, with constant angular velocity, where relative size and lateral position were calculated from the sine and cosine of each angle relative to the starting point.    I intentionally did not include the full orbital path, in order to keep the file size below mozilla's limit, and also to provide a break in the animation to relieve the demand on PC resources.   Time on = Time off.\nIt's a good thing our planet doesn't orbit every 5 seconds ;o)\n(animation, red, blue, purple, yellow, planet, orbital motion)\n(c) 2012 BrianZ  All Rights Reserved"
}