the physics is nice (nicer if you use vector) :D so you now just play with graphics ! (add the picture of earth, sun, atg) (or maybe a shadows!?) nicer if the background is black :D

yeah ~! this is not totally a gas ! this is its molecules ! :D *i think what greenfoot is best for..education!

thanks ! i uploaded the new explosion. yes, for while maybe i should handle this with your code (destroying the missile) :D yes, somekind of "unrealistic" naaah, thats what i think mjrb4 ! :D the Vector class give its own x and y, i just work on the "display" ;) sure, the Vector class, and the SmoothMover class Should i add a Heat class ? (so the missile seek heat, not the jet :D)