Eccentricity & GR precession; Mercury vs. GP-B How big a factor is the Eccentricity of Mercury orbit in contributing to its precession? GR precession has been confirmed in the Gravity Probe B orbit even though it has an eccentricity of zero. The GP-B used a gyroscope to take the place of a detectable aphelion, while Earth has a nearly circular orbit with an eccentricity of 0.016 it gives measurable aphelion that allow modern observations the ability to see the small precession undetectably to 19 century astronomers. Is it the large orbit eccentricity of 0.205 that gives Mercury such a large and easier to notice precession of 43 ArcSec/century? I assume by moving up and down between different levels of GR curved space the effect on precession is magnified. Does anyone have a reference to show or explain what how or what part of the GR formulas account for the eccentricity contribution? If Mercury orbit was a more circular eccentricity of 0.01 what would the precession be? If eccentricity is doubled to 0.41 is there some function to describe how much the precession would increase?