How to implement earth and sky

I know that this may be more related to computer graphics, rather than OpenGL but many people may be able to answer my question here.
I want to animate a simple object using OpenGL and I have written the code and it does well. Now I want to show some background like ground and sky, but I do not know how to do this.

Vadood Etminan

there are lots of ways to implement a ground and sky…

…for the ground, you can simply use a textured quad…

…and for the sky, you can try a “skydome” or “skybox”…try searching in google or something…

Tin