We have seen that the orbits of the planets around the sun can be found, to a good approximation, by only considering a two-body system (a planet and the sun) interacting through a central force. However, all the other planets cause slight variations in the predicted path of an individual planet. Astronomers have been able to calculate the expected precession of Mercury’s apsides (due to the forces of other planets) to be 531 arcseconds per century, and they have observed that the actual precession is 574 arcseconds per century. This leaves a difference of 43" that could not be explained by uncertainties in calculation or measurement and which was noticed as early as 1845.
As we can see from the quote above that the precession of mercury had been calculated to an amazing degree of accuracy well before Einstein's theory of general relativity. To account for the difference between the calculated value and the one predicted by Newton's theory, they came up with mistaken ideas of Vulcan and dust clouds. It was Einstein's theory which gave a final answer. The orbits of all other planets also precess but the value is too small and astronomers in the past didn't notice it for other planets other than Mercury.
Perihelion is the closest point to the sun while the aphelion is the farthest for any orbit.
My question is about the Newtonian precession of 531 arcseconds per century. Suppose, we are looking at the picture shown below from above the solar system. It could be assumed that all the planets lie in same plane. Looking from the top, one would say that precession is taking place counterclockwise as if some force is gradually pulling the entire orbit of planet Mercury in counterclockwise direction.
The Newtonian precession of 531 arcseconds per century was the result of gravitational attraction of other planets onto Mercury. The picture below shows the relative sizes of the planets and their distance from the sun. I think that Mercury should be affected most by Venus, Earth, Mars, and Jupiter since these planets are relatively close to Mercury's orbit. Mercury takes almost 88 days to orbit the sun.
As I said earlier, it appears as if Mercury's orbit is being pulled in counterclockwise direction which suggests, at least to me, that mostly other planets were in such a configuration that their resultant pull onto Mercury was in the counterclockwise direction. If it was not true then there would be times when Mercury's orbit could precess or slide in clockwise direction as well. The diagram below is a crude attempt to show you how I'm thinking. The orbit in cyan is for Mercury, the orbit in red is for Venus, and so on. The arrows show the pull of shown planets onto Mercury.
Could you please let me know if I'm thinking along the right lines? I'm trying to understand it intuitively.