This tool allows you to alter the size, color, and amount of layers in a sphere representing the different layers a planet might have. You can also add a note for each layer, perhaps to note down the temperature, makeup, or anything else you wish to note down. The tool is very simple to use, but I've written down the instruction below.
This tool is obviously aimed at planets, but you can use it as a representation of all sorts of circular objects. Your imagination's your only limit.
The default setup is 8 layers, all set at various sizes, and in various colors. But you can change each layer as follows:
Selecting a layer: You can select a layer by simply clicking on it. It'll receive a white border, and a text field will appear above all the buttons. The color field will also be set to the background color of the selected layer, which further helps indicate whether a layer is selected.
Toggling layers: You can toggle layers on and off by simply clicking on the 'Toggle layer X' buttons.
Size: The size can be changed by selecting a layer, entering a number (up to 500) in the size input field, and then clicking the 'Set size' button.
Color: The background color of a layer can be changed by selecting it, then picking a color using the color picker next to the 'Set color' button, and then clicking that button. Note that older browsers won't have a color picker, so you'll have to enter a hex value yourself to set the color.
Toggle texture: Pressing this button will toggle the texture of the layers. Some might prefer just a smooth color over the different shades.
It's possible to save up to 5 planet setups, you can do so by simply clicking the save buttons. This will save the entire setup, including the notes for each individual layer, locally in your browser. This only works if you don't use incognito mode, and only if you use a modern browser (so no IE7 for example). You can close your browser after you've clicked save, it'll still be there when you open it again.
When you want to load a planet, simply click the corresponding load button, and it'll load the planet you've saved before.
You can print a planet, along with all the notes you've made, by simply using the default printing option in your browser. "Ctrl + p" on Windows, or "Command + P" on Apple will usually do the trick.
The text will be printed in black. If you intend to print your creation, I recommend not leaving gaps in the layers you use. So if you need 4 layers for example, use layers 1 to 4, not 1, 3, 4, and 8 for example. This way, if you have any notes written, all the notes will be printed below each other, rather than with gaps in between. It's good to save paper after all.