The Perihelion Effect

Distance vs Velocity over the year

Change in earth’s orbital velocity over 1 year

Actual JPL Ephemera Data

Note the strange bumps in the acceleration near the time of perigee and apsis



Distance from earth to sun


Distance vs Acceleration

60 month extrapolation


Range (“delta”) and range-rate (“delta-dot”) of target center with respect
to the observer at the instant light seen by the observer at print-time would
have left the target center (print-time minus down-leg light-time); the
distance traveled by a light ray emanating from the center of the target and
recorded by the observer at print-time. “deldot” is a projection of the
velocity vector along this ray, the light-time-corrected line-of-sight from the
coordinate center, and indicates relative motion. A positive “deldot” means the
target center is moving away from the observer (coordinate center). A negative
“deldot” means the target center is moving toward the observer.
Units: AU and KM/S

Joseph Schuster

The Power of Perihelion

We are all familiar with the idea of holiday stress. That feeling that time is going by faster and faster from Autumn until New Years.

Read More »