This is far more challenging than painting a half circle shape. Here we have a sphere and a set of ellipses. We need to create the impression of a round shape and the key to this is the line that divides the lights from the dark. Any curved line on a sphere creates the impression of a rounded shape.
How to … start with a very precise drawing of the planet and the overall shape of the rings. Use any item that is a suitable size as a template for the planet. You can draw this freehand but you have to make sure there is symmetry from one side of the shape to the other, if one side differs from the other this painting will not be successful. So … use a dinner plate if need be.
The ellipse shape is slightly tilted the right hand side is slightly higher than the left.
Once you have completed your drawing (take a photo of this on a mobile telephone to evaluate the strength of your drawing – I do this as second nature now – it is so useful) you are ready to paint.
Work from dark to light so have an appropriate amount of black, not chromatic black, ready on your palette. Paint in the semi circle shape on the left hand side of the planet first as this gives you shape for the planet and the rings. We are using negative space painting to start. Then paint in the dark side of the planet and then the cast shadow. Your directional brush stroke for the planet should be rounded to the shape of the planet and the directional brush stroke for the shadow should be horizontal, so the two shapes are slightly divorced from one another. Then paint in all the background.
And hey presto! With your negative space painting completed you have the overall shape of your subject. Now paint in the smaller areas of black. The rings could be drawn in with watercolour pencil and then wash over them with a light wash of a cream colour (yellow + white).
The light colours: a blue on the top of the planet, yellow ochre, cream, purple and a small amount of green was the palette I employed. It does take a while to build up all the different tones, and at the very last stages of your painting glaze (wet paint on dry) over the areas on the rings on the right of the composition with a light wash of black.