Comets are a lot like the Toronto Maple Leafs hockey team.  They get you really excited early on, and just when your hopes are highest, they become a continual disappointment.  Then you go through the same thing the next time around.  More often than not, comets with great expectations fizzle or burn up.  Here are my top five comet fizzles from recorded history. But comets, unlike the Leafs, can sometimes succeed.  They can live up to expectations and become a beautiful night sky jewel.  Hale-Bopp comes to mind from 1997, when it exceeded the expectations and became the comet of a...