Solar System made in OpenGL

I've continued my journey into the OpenGL Adventure and came out with another little project. It's not very complicated, basically made of multiple simple operations like translation, rotation and scaling combined.

For example, for the moon, the smallest object in the scene, it's not attached to Earth like it would be in a normal animation editor. For this case we apply a rotation, then translation, another rotation, one more translation, and finally a scalling to get the moon rotation. We apply this sequence at each frame modyfing the angle of the rotation.