The background from Rise of the Strider :)
[Edit] Added a couple of lighter rings to the planets rings.
Its been brought to my attention that this background has a likness to a background in MetalSlug which it does as I used it as reference to see how the how the rocks, foggy atmosphere etc are done (not resized, copy and pasted, pixeled over etc), and used it in game as I began coding. I forgot about the ref as it was drawn awhile ago and should've checked before unloading.
Ref source: spriters-resource.com/arcade/ms2/sheet/32269