|Astrophysics on the flyby is fun|
Gravitational precession-by-solar-spin-backpass-subduction of Mercury's perihelion:
An asteroid approaching a significant gravitational mass, planets, stars, accelerates towards, fast-passes, and decelerates beyond, leaving the asteroid advanced in position though with no greater end-velocity if not significantly redirected ... eg. planet Mercury, orbiting the sun in 88 days while the sun rotates in 27 days (innards slower ~34 days), is being pulled backward continually by the solar nearside mass continually passing, and to a lesser extent forward by its farside ... Nevertheless, Mercury has orbital velocity, and its ephemerides were mistaken; except, Mercury does back at perihelion, dropping deeper and perihelion precesses ... Newton is said to have computed the effects of the planets but no mention of this solar tidal advance-- whence Einstein's correction thereto is dubious simplistic calculatory serendipity, called, frame-dragging, that is actually Newtonian-were-he-more-thorough, back-passing.
NB. Recognize that this is not velocity-energy-loss as in resistance-drag, but back-passing positional delay only while near; Normal-progress apparent-velocity-energy is recovered spontaneously as it recedes from perihelion .... This is somewhat akin to an inductive transformer passing-back flow in its secondary:-- With no observable resistance-drag, Mercury's secondary back-flow is 'elastic'.
(Nevertheless, we expect some of both, as cumulative-directional aether-slippage corroborates its top-energy-flyby-motion.)
A premise discovery under the title,