知る vs 知っている (know vs come to know)

知る is the punctual verb 'to come to know, become aware,' while 知っている (the ~ている form) marks the resulting state 'know, be aware of.' Asking 知っている? ('do you know?') is correct; asking 知る? would be unnatural. Parallel pattern with 結婚する, 死ぬ, 落ちる, etc.