Inside the Dome
Before we import the dome image, let's prepare a layer for it.
-Click on the expander icon (the wavy line) at the top right of the Layers panel and choose "New Layer..." to open the New Layer dialog box.
-Type the word Dome and press Enter
Now let's import the Dome image. Click on the title bar of the Dome layer to make the layer active and...
-Choose File > Import to open the Import dialog box
-Browse to the Dreamcatcher folder
-Click on the Dome.png file
-Click on Open to copy the image to the clipboard and close the Import dialog box
The cursor changes to an insertion pointer 
to let you know that your image is ready to paste.
-Move the insertion pointer to the top left corner of the canvas and click once.
The Dome.png file is now sitting on the top left of the background image.
There's one small patch to make in the dome image before we start doing more interesting things to it. If you guessed it was to cover up the small dark square at the bottom, you're right. Make the background layer invisible by clicking on the eye icon of the Beach layer.
Next: Creating a vector patch