First, lets create some texture. Find an image of texture or rock or whatever you want to use. This is what I started with:
I cropped it down to the part I wanted:
Next I put that on a new document four different times all going opposite directions:
Then go to Edit > Define pattern and save it as texture or rock or whatever suits you.
Now on to the planet.
Create a new document, fill it with black.
Create a circle with the Elliptical Marquee tool. Color it whatever color you want. Duplicate it two times but make these two layers just black circles.
Add the following effects to the atmosphere layer:
Set the layer mode to Screen.
Now on a new layer add your texture (or pattern if you want to call it that). Go to your paint blucket, choose your pattern:
Go To Filter > Distort > Spherize. Do this a couple times.
You will have something similar to this:
Now turn your shadow layer on. Select it and move it to whatever area you want.
Go to Filter Blur Gaussian Blur. I used 50 pixels but you use whatever you want.
Or you could lower the opacity of the shadow layer to 95%, so its not completely covered.
I wanted the orange color to show up a little bit more so I did a color overlay on the rock later:
That left me with this:
You could also use the Sharpen tool to add even more texture:
Now we will add some rings.
Open a new document, fill it with black. Make your default foreground and background layers are black and white, you can do this by just pressing D on your keyboard.
Go to Filter > Render > Clouds.
Now go to Filter > Distort >Twirl and use the highest setting.
Now we will erase the middle and around to get our rings.
I used the Elliptical Marquee tool to cut out the outside and the inside.
Then I went back over the edges with a soft brush and lowered the opacity to about 60%.
Don’t worry about making it perfect. (I put mine on a black background now so you can see it better)
Now take your transform controls and make it as small as you need for it to look like rings.
Go to Filter > Noise > Add Noise:
Now Go to Image > Adjustments > Levels and move the middle arrow until you get something similar:
Now we are going to go to Image > Hue/saturation to add some color and match it up to the planet.
Move it to your planet photo:
Set the layer mode to screen and erase parts so it looks like it goes around the planet.
Now I also duplicated my shadow layer. I set the opacity to 61%. I want some of the ring darkened but not all of it. I also don’t want it overlapping my planet shadow so I erased this layer except for where it covers the ring. If that was confusing here is what I meant in pictures. (I am temporality am hiding my original shadow layer so you can see what I mean by I just left this new shadow layer on the ring only and not the planet):
It just makes it look more realistic I think.
Now turn your original shadow layer back on. Here is my final image:
And, for a slighty altered look, you can take the Burn tool, lower the opactity and go over the ring layer: