„My Solar System” from PhET (University of Colorado)

https://phet.colorado.edu/sims/html/my-solar-system/latest/my-solar-system_all.html

I encourage you to click/play around with this simulator.

It’s only (?) an educational simulator but it is opensource, has very neat codebase, seems solid and v.much work done, and is quite fun: GitHub - phetsims/my-solar-system: "My Solar System" is an educational simulation in HTML5, by PhET Interactive Simulations.

What is to be noted - simulations are unstable for more than 2 bodies - everything crashes or fell apart after a minute or two.

By the contrast - two bodies systems are overly stable - I couldn’t make two bodies collide by deliberately changing their masses “live” trying to create such scenario.

I do not suspect any fault play here, project is neat and honest imo, it is like it is.

It seems like a model lacks something.

The creator, Augistin Vallejo, is an Astronomy Undergrad, clearly highly talented in coding and visualising.

He also seems pretty passionate, his website has a dozen of atro-projects AVV | Games, one of which is heliocentric/geocentric visualization.

/after all those collisions I wonder if gravity might be a simple moment of inertia conservation force - you know, to keep everything as in the clock/

// I’m not affiliated w/ author, just found it interesting and aligned w/ this forum //


Edit:

At certain (stable) setup moon with 1/10 of weight is completely taking over a planet: screenshare video