Any tips for trapping objects as moons?

[bterrill]

My planets just seem to be hungry and eat every object that comes close. I pretty much setup my star and put a few planets and then make a few huge mass objects , explode them in to bits, and let those bits form new planets / add mass to my original planets / get eaten by star/planet , but never seem to capture objects in to orbit of planets automatically.

Definitly have no problem forming new planets out of explosions , or getting objects close to my planets through random gravity interaction just often my planet gobbles them up or it seems uneffected by the planet , even if it's a tiny astroid and a 90 jupiter mass planet.

How often do you guys trap objects as moons?

[Darvince]

Nigh impossible for me.

[plastik2k11]

It does seem difficult, although by luck I did once get a fragment of an exploded Venus to become a moon of earth. When it exploded, it headed out towards Earth's orbit and 'inserted' itself rather nicely. But I guess that was all down to luck with the timing of the explosion and the velocity being just right as it approached Earth.

[bterrill]

Yeah I have only trapped one , though I do run the sim sometimes when I am sleeping. I like to play my system for a few days and then make a new one.

But often , for a few hours I will sit there and add new objects which get flung out sometmies or just eaten (flung out due to playing with binary star systems)

I was setting bigger massed planets up with their own moons but often they will get ripped away, which I don't mind because I like how chaotic the systems become over time , but it would be great if there was more objects orbitting the planets.

Of course, in non-binary systems , I find it's much easier to keep my moons in orbit that I place manually but I really do like the binary star system much better because of the other star effecting the other stars bodies and sometimes planets fling from one star to the other which is kind of cool.

Thanks for the comments , it seems that I'm not the only one then.


p.s. I love this simulator. I've got about 4 friends to buy it lol

[lukas]

Trapping flyby objects as moons is actually a very rare event. It is because there are two possible fates of a small object passing by a large one: a (usually highly eccentric) orbit where the object return to spawn point each lap, or a hyperbolic path, where the flyby just change the direction of the trajectory.

In order to reach a nice circular orbit as our moon have, the flyby object must be affected by other forces than the gravity of the planet. Possible forces include the gravitation from a third object like an existing moon, impacts and breaking by tidal forces. However, disturbances like that are also likely to change the trajectory in an "inappropriate" way, causing a collision or unbinding an eccentric orbit.

[78stonewobble]

I just bought the full game but messed around with the demo for a while.

If you try to run the "small moons" sim.

The different moons coalesce for me into several "combined" moons (which then merges). A few gets flung out but often one single moon starts an orbit around one of the "combined" moons. It's not a stable orbit and after a few ingame days it merges with the bigger moon.

Quite interesting to watch.

[atomic7732]

A great way to trap a moon, it's thought Triton was caught this way, and possibly Mars's moons. You can create a binary asteroid (or another planet with a far out moon), and allow it to pass nearby. If one of the binary pair, or moon is in the right spot on it's orbit, usually when it's moving near (but not exactly) 180 degrees to the other object, it can become caught on the other planet.

[bterrill]

Funny thing is after I made this post I was up to , I don't know, 10,000 object system or so (over about a week) and I witnessed about 3 captures within a few hours.

Like mentioned, they were  achieved by other passing by bodies "helping" them in to the bigger object. Don't get much luck otherwise, but looking around our own real system... obviously trapping moons isn't too common , considering the amount of asteroids and comets in the milkyway and the small amount of moons around all the planets.

It is just rare all around I suppose. Binary asteroids? Interesting..... never thought of this!

I took about 2 weeks off of this game and just started back up 2 days ago and been working on a new solar system so I'll tinker with the binary asteroids just because I find binary orbiting really neat.

[Dan Dixon]

If you can get a moon to be ejected from a 3 body system (where one of those bodies is the moon), then by selecting everything and 'Reversing Velocities' you can get the moon to be recaptured as everything runs in reverse.

Does that help?

If you get this working, post the simulation where it's been saved right after you've reversed the velocities.