Gravity simulator.

dlofnep

http://phet.colorado.edu/sims/my-solar-system/my-solar-system_en.html

I had fun toying with this. It's a solar system & gravity simulator. It's difficult to create any sort of functional solar system that doesn't eventually destroy itself. Give it a go

Rubecula

Seemingly simple (it isn't) and a bit of fun.

dlofnep

It's a shame you can't zoom out and add more bodies. Interesting to see how a planet is ejected from the solar system by a larger planet.

muppeteer

Who needs spirograph when you have a solar system to play with.

Cú Giobach

Well, that was fun.
Gravitational snooker.

shizz

Brilliant stuf

dlofnep

Been toying with this a bit more... It's interesting to see how a larger planetary body can bring on an elliptical orbit of a smaller planet. It's easy to see why planets beyond the 3 gas giants are extremely elliptical, while any before them have a more rounded orbit.

shedweller

My 6 year old loves to play "God" with it. More like Darth Vader the way he was laughing when planets fell into the sun or got flung out of the system!

Should i be worried?

John mac

My 5 year old loves it too, tries to see how long he can make them survive , and what patterns they make,

dlofnep

This one is fun too

http://www.nowykurier.com/toys/gravity/gravity.html

You can add as many objects as you like, define their mass, etc.. If you click generate proto-disk you can get an idea of how a solar system is formed.