Planet simulator that models gravity to make objects move around. Pressing the Green Flag loads a data set (I recommend Turbo Mode by Shift-Clicking). Pressing the space button launches this data set so that you can see what happens. You can create your own verions using the custom block 'Add Object at...'
There are plenty of more elegant ways of sorting out the velocity update that probably improve speed - mine was somewhat clunked together. The pictures are from assorted places and found using Google - I hope my usage of them is acceptable.
