Silly question about comets and like.

The Sun.

Wouldn't all timed pass-bys be the same then? i.e.. Hale Bop is every 75 or so years. There are some that come around yearly, every 2-3 years etc.. Velocity is an obvious factor, BUT, if they were on the same travel course then chances are the slingshot would make most the same speed?

: (

I think the weight of the comets change as they disintegrate in space and they also pass by celestial bodies in a different pattern on their orbit so that changes things as well. Those two things alone would seem to change the orbit somewhat.

Certainly. I haven't studied nor given much thought to this question. Mass/Makeup of the comet changing would certainly a few calculations / trajectories.

So is every comet lopping out past our sun and slinging back? Since the celestial bodies are always moving position, (i.e.. halleys cycle) wouldn't that totally shoot it off in another direction? That's is saying we're in the same spot every 70 some years.