Main-terrain with Terragen: The rock-formations are created with "generate terrain"- settings: Perlin Noise - Glacination-,Canyonism- and Size of Features-values at 3/4th with random origin. Then with "modify terrain" using "Scale Vertical" once with 200% ! Sky- and light- and haze-colours set green, playing around with overall-haze-setting until scene covered with light haze-layers. Larger clouds with 3/4th-slider-setting and colour light-green.

Additions: The extra planet/moon are added with PaintShopPro5. I´ve used the gradient-blur-function to blur the edges, used the drop-shadow-function to add some green-lighted atmosphere. The texturing of the planet/moon is done with the airbrush-, RGB-lighten-tools and a little smoothing-retouch.