# What body has the longest path around the sun **URL:** \ **Category:** Factual Questions\ **Created:** [May 15, 2018, 2:14am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185 "2018-05-15T02:14:30Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [May 15, 2018, 2:14am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/1 "2018-05-15T02:14:30Z")
See title. 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? ---
**Author:** ![rat\_avatar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rat_avatar/32/255_2.png) [@rat\_avatar](https://boards.straightdope.com/u/rat_avatar)\ **Post date:** [May 15, 2018, 2:18am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/2 "2018-05-15T02:18:50Z")
The longest known comet period I think is still Hyakutake, which has a period of ~70,000 years. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [May 15, 2018, 2:24am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/3 "2018-05-15T02:24:31Z")
> [@Lucas\_Jackson](#): > > See title. > > 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. ---
**Author:** ![rat\_avatar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rat_avatar/32/255_2.png) [@rat\_avatar](https://boards.straightdope.com/u/rat_avatar)\ **Post date:** [May 15, 2018, 2:32am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/4 "2018-05-15T02:32:40Z")
As far as dwarf planets and larger Sedna has an orbital period of 11,400 years. ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [May 15, 2018, 2:40am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/5 "2018-05-15T02:40:23Z")
Mercury Venus Earth Mars Asteroids Jupiter Saturn Uranus Neptune Pluto The Check in the Mail 😉 ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 15, 2018, 3:26am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/6 "2018-05-15T03:26:11Z")
> [@rat\_avatar](#): > > The longest known comet period I think is still Hyakutake, which has a period of ~70,000 years. [Comet West](https://en.wikipedia.org/wiki/Comet_West) has an unresolved period that could be anywhere from a quarter million years to 6.5 million. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 15, 2018, 3:36am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/7 "2018-05-15T03:36:31Z")
BTW, an Oort cloud object with a circular orbit 100,000 AU out (to pick a round figure) would have an orbital period of around 45 million years. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [May 15, 2018, 3:52am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/8 "2018-05-15T03:52:43Z")
For non-comets, it’s currently [2015 KG[sub]163[/sub]](https://en.wikipedia.org/wiki/2015_KG163), which has a period of 23,094 years. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [May 15, 2018, 4:26am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/9 "2018-05-15T04:26:22Z")
Actually, I did my math wrong–the above theoretical Oort cloud object would have a period around 90 million years. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 15, 2018, 10:44am UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/10 "2018-05-15T10:44:59Z")
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. ---
**Author:** ![Encinitas](https://avatars.discourse-cdn.com/v4/letter/e/ee7513/32.png) [@Encinitas](https://boards.straightdope.com/u/Encinitas)\ **Post date:** [May 15, 2018, 12:40pm UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/11 "2018-05-15T12:40:20Z")
What body has the longest path around the sun? Uh, yo mamma? ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [May 15, 2018, 1:15pm UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/12 "2018-05-15T13:15:47Z")
Jimmy Hoffa would have been my guess. > [@Darren\_Garrison](#): > > [Comet West](https://en.wikipedia.org/wiki/Comet_West) has an unresolved period that could be anywhere from a quarter million years to 6.5 million. Based on pics during its close approach in the 70’s I believe it broke up. ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [May 15, 2018, 1:16pm UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/13 "2018-05-15T13:16:55Z")
[dupe] ---
**Author:** ![burpo\_the\_wonder\_mutt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/burpo_the_wonder_mutt/32/365_2.png) [@burpo\_the\_wonder\_mutt](https://boards.straightdope.com/u/burpo_the_wonder_mutt)\ **Post date:** [May 15, 2018, 2:20pm UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/14 "2018-05-15T14:20:14Z")
When I was a kid, “they” said Comet Kohoutek would be back in 250,000 years. Does it really take that long to pick up another naked space vampiress? ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [May 15, 2018, 4:01pm UTC](https://boards.straightdope.com/t/what-body-has-the-longest-path-around-the-sun/814185/15 "2018-05-15T16:01:24Z")
Wikipedia’s article on [near-parabolic comets](https://en.wikipedia.org/wiki/List_of_near-parabolic_comets) lists one discovered by PANSTARRS, C/2012 S4, with a period of 130,000,000 years. It last visited in 2013. Is it too early too stock up on supplies for the return party? Anyhow, there’s a Wikipedia [page](https://en.wikipedia.org/wiki/C/2012_S4) on this one which is difficult to parse regarding orbital period. Perturbations are a bitch.