Q on Satellite Orbits + Regression of Nodes

[JamesGoh]

Currently I am studying about mechanics of satellite orbits, however I cannot seem to understand in the regression of nodes, why the line of nodes would rotate in a direction contrary to that of the actual satellite orbit (irrespective if it is prograde or retrograde orbit) ?

Ive tried drawing diagrams of the Earth and retrograde and prograde orbits surrounding them, however I still cannot grasp the concept ?

Is there anything I am not taking into consideration ?

 

[D H]

You are missing what causes the regression of the nodes. The right ascension of the ascending node is a constant in the simple point mass model of an orbit. The node regresses because the simple point mass model is not quite right. The Earth isn't spherical, for one thing. The Lagrange Planetary Equations describe the variation of the osculating orbital elements.

 

[JamesGoh]

lol I am currently studying about the effects of the Earth's oblateness on satellite orbits so thanks for the reminder :)