I was reading an article about the hypothetical Planet 9. And it got me wondering what body takes the longest time to orbit the sun. As far as planets go I think Neptune is the answer but surely there are comets and such that take longer.
So, what known object takes the longest to orbit the sun?
Bonus points… what are the chances that there is a Planet 9?
Well Pluto has a longer orbital period then Neptune, IIRC it has a orbital resonance of 3:2 with Neptune.
The answer to your question is so far as we know is the galactic center which is a black hole. As the sun orbits it, it also orbits the sun. Since the BH is a singularity the orbit of the BH is also outside the singularity.
Also yes there is a planet 9, it’s Pluto, time is just a dimension after all.
The orbital periods of comets aren’t actually well-defined. Periods only make sense for things that are periodic. But when a comet passes through the inner Solar System, its orbit will be changed slightly, and what’s a slight change in the inner system will add up to a very significant change in the outer portions of its orbit. It’s quite possible to have, say, an object that comes through the inner system the first time, then comes back again 7,000 years later, then again 4,000 years after that, and then gets put on an escape orbit that’ll never come back again at all.