"In the planetary system, solar gravity determines the orbits of all bodies larger than dust particles for which other forces become important. But even for dus

"In the planetary system, solar gravity determines the orbits of all bodies larger than dust particles for which other forces become important. But even for dust, gravity is an important factor. Near planets, planetary gravity takes over", §3.1 of Krüger & Grün's Chapter 29 in Encyclopedia of the Solar System (2014) <https://doi.org/10.1016/B978-0-12-415845-0.00029-3 https://doi.org/10.1016/B978-0-12-415845-0.00029-3> (it's on scy hob :) ). See Table 29.4. Where dust is gravitationally interesting at the present age of the solar system is probably in ring/moon interactions, but mostly with the moon acting on the ring dusts as with Saturn's Daphnis and Pan (Cassini). Of course there was a lot more dust doing a lot more interesting things gravitationally much earlier in the solar system's history, which might be interesting if you decide to use your approach to simulate the solar system's past (some of that dust could be related to your link to the massive early sun hypothesis paper). :-) Your other paper on stellar flybys provokes an interesting question: could a fly-by deposit a significant mass of trans-Neptunian dust? I'd wager a lot of fresh dust captured out there could increase the eccentricity of planetary orbits through your 0.9 threshold. Although not plausible for the solar system, relatively high mass-density dust around compact binaries can drive the compact binary's orbital evolution. See for example the very fresh Siwek, Weinberger & Hernquist (2023) <https://arxiv.org/abs/2302.01785 https://arxiv.org/abs/2302.01785>, reasonably summarized at <https://astrobites.org/2023/03/13/will-it-merge-investigating-how-gas-disks-can-determine-the-future-of-a-binary-black-hole-system/ https://astrobites.org/2023/03/13/will-it-merge-investigatin...>.