OpenGL - Rotating the moon around the sun without spinning?

I am working on a graphic model of the moon orbiting the earth. Right now, the moon is spinning around its y axis, spinning around the earth. How can I stop the moon from spinning, but still allow it to go into orbit? Here is the code ..

Edit: Added animated video to demonstrate the problem:

http://www.youtube.com/watch?v=ltGV4pXD5Cs

void DrawInhabitants(GLint nShadow)
{
    static GLfloat yRot = 0.0f;         // Rotation angle for animation 

    if(nShadow == 0)
    {
        yRot += 0.2f; 
    } 

    // Draw the randomly located spheres
    glBindTexture(GL_TEXTURE_2D, textureObjects[MOON_TEXTURE]); 

    glPushMatrix();
        glTranslatef(0.0f, 0.1f, -2.5f);

        glPushMatrix();
            glRotatef(-yRot * 2.0f, 0.0f, 1.0f, 0.0f);
            glTranslatef(1.0f, 0.0f, 0.0f);
            gltDrawSphere(0.1f,21, 11);
        glPopMatrix();

        if(nShadow == 0)
        {
            // Torus alone will be specular
            glMaterialfv(GL_FRONT, GL_SPECULAR, fBrightLight);
        }

        glRotatef(-yRot, 0.0f, 1.0f, 0.0f);
        glBindTexture(GL_TEXTURE_2D, textureObjects[EARTH_TEXTURE]);
        gltDrawSphere(0.3f, 21, 11);
        glMaterialfv(GL_FRONT, GL_SPECULAR, fNoLight);
    glPopMatrix();
}