These settings are relative to the 0,0,0 coordinate origin that starts on the surface of the planet in the default scene and are referenced from the center of the planet itself. That's why the distance starts out as 6.378e+006, which is exactly equal to the radius - or one half the diameter of the planet - placing the 0,0,0 point just on the surface of the planet.
Distance simply controls the distance of the center of the planet from 0,0,0. Elevation is elevation of the planet above or below the x,z plane relative to the 0,0,0 coordinate origin. Heading is essentially the same - 360 degrees of heading relative to 0,0,0. These are all similar to the sun controls incidentally. Thus if the planet is *at* 0,0,0 Elevation and Heading have no effect. So you can't use these controls to rotate the planet. The effect is greater the further distant from 0,0,0 the planet is.
- Oshyan