We're going to apply a new Location to the "nearby planet" layer, but first, so you can get a feeling for how the Clipping area and the fractal pattern interact, do the following:

Ctl-drag the image in the Fractal Window upward about 5 or 6 inches, then release it (make sure the "nearby planet" layer is highlighted in the Layers tab and is the only layer whose editable icon is "On".
(While you're dragging, it will seem like the "nearby planet" is going off of the page, but it will float back into place when released.)

 
Observe how the coloring of the planet changes as you drag; that is, how the underlying coloring of the layer moves beneath the stationary circular cutout of the Clipping Shape.

When you have done this, press Ctl-z to undo the Ctl-drag.

 
The image should now look like this:

 
Basically the planet is what I wanted. Its coloring is almost right, but not quite. It needs to be more dusky in order to fit into the low-key tones of the scene and also to add to the sultriness of the mood.

Compare the curent, unfinished planetary object in the upper half of the illustration below with the completed planetary object in the lower half.

 
We will accomplish this final, deepening touch by a combination of a) rotating the gradient, and b) reducing the opacity, of the "nearby planet" layer.