Top tip for a silky smooth chin is to use the old ladies hair conditioner rather than shaving creams and foams, It works a blinder. I use to hack myself to bits on my neck, even with a new blade, but using conditioner (even cheap stuff) is really good.
Give it a go next time you have a shave...
I think you will find that its a impact crater. Sure I read somewhere that folks witnessed the event back in the 11th century. More than likely wrong though :thumbsup: