What's an aphelion marker?

[Ijon Tichy]

Hi spacefarers,

I noticed that the surface MFD sometimes displays red markers labeled "AP" and "PE" in its altitude ribbon. The handbook tells me those are the aphelion and perihelion markers, but does not give further explanation.
I can't figure this out. What has sun distance got to do with my altitude above ground? So, what are those markers, and what are they good for?

 

[Artlav]

I noticed that the surface MFD sometimes displays red markers labeled "AP" and "PE" in its altitude ribbon. The handbook tells me those are the aphelion and perihelion markers, but does not give further explanation.
I can't figure this out. What has sun distance got to do with my altitude above ground? So, what are those markers, and what are they good for?

Apoapsis and Periapsis would be more precise, which are generic terms for highest and lowest altitude over the current planet.

Which handbook do you use?

 

[Ijon Tichy]

Which handbook do you use?

The "Orbiter Space Flight Simulator 2006 Edition" PDF that comes with the game.

Ok, now I get it! They are just the ApD and PeD figures of my current orbit, right? I was confused by the "helion" suffix... Thank you!