Particularly the Earth’s.
The Sun is emitting the solar wind. This must be pressing against planets and creating a drag effect as the planets push through it. The pressures are minuscule, but over the eons, have they added up to a significant effect?
In the relatively short term (millions of years) the effects of the solar winds are small enough that they aren’t significant.
Over longer periods though, the effects do become significant. Not only does the solar wind push against the planets but it also tends to strip off small bits of mass and those changes in mass for the planets and asteroids also affects their orbits. There are other factors as well that affect the long-term stability of the solar system, such as the gravitational interactions between the planets to each other and the gravitational involvement other objects like asteroids and comets. All together, all of these effects make the long-term stability of the solar system difficult, if not impossible, to predict with any accuracy.
But is it possible to calculate backwards?
[THREAD=400845]Sunlight pressure on planets[/THREAD]
Stranger