# Donut-shaped planet
**URL:** https://boards.straightdope.com/t/donut-shaped-planet/961249
**Category:** In My Humble Opinion
**Created:** [March 17, 2022, 3:42pm UTC](https://boards.straightdope.com/t/donut-shaped-planet/961249 "2022-03-17T15:42:02Z")
**Posts on this page:** 6
**Page:** 4
### Author:  [@Steve\_MB](https://boards.straightdope.com/u/Steve_MB)
#### Post date: [March 18, 2022, 3:57pm UTC](https://boards.straightdope.com/t/donut-shaped-planet/961249/61 "2022-03-18T15:57:55Z")
> [@Sage\_Rat](#):
>
> I would probably expect the planet to be spinning inline with the Sun so the inner part of the ring would be permanently fairly dark? The ice ring should probably be carried through the whole inner section.
Also, wouldn’t the net gravity on the inner part of the ring be low (or even zero at the very innermost part) because of the opposing pull of the further (but larger) portion of the ring?
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### Author:  [@k9bfriender](https://boards.straightdope.com/u/k9bfriender)
#### Post date: [March 18, 2022, 4:02pm UTC](https://boards.straightdope.com/t/donut-shaped-planet/961249/62 "2022-03-18T16:02:37Z")
I doubt it, as the centrifugal force required to keep the planet in the toroidal shape would necessarily be much greater than the pull of the other side of the planet.
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### Author:  [@naita](https://boards.straightdope.com/u/naita)
#### Post date: [March 18, 2022, 4:32pm UTC](https://boards.straightdope.com/t/donut-shaped-planet/961249/63 "2022-03-18T16:32:03Z")
The known precursors of a nice homey ablate spheroid planet are an infinite variety of slightly less nicely uniform blobs of different sizes. Is there a valid hypothetical path from any configuration plausible to have existed in the universe to a toroidal planet?
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### Author:  [@F.U.Shakespeare](https://boards.straightdope.com/u/F.U.Shakespeare)
#### Post date: [March 18, 2022, 4:58pm UTC](https://boards.straightdope.com/t/donut-shaped-planet/961249/64 "2022-03-18T16:58:07Z")
The topic of this thread is intriguing. I may have to steal it.
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [March 18, 2022, 5:32pm UTC](https://boards.straightdope.com/t/donut-shaped-planet/961249/65 "2022-03-18T17:32:07Z")
I realize that the Repository of All Human Knowledge is a lot harder to search now than it used to be, but there’s a [definitive answer](https://www.straightdope.com/21343064/what-would-gravity-be-like-on-the-inside-of-a-donut) to this, written by a highly intelligent and no doubt very handsome physicist. Even if the planet weren’t spinning at all, and were instead maintaining its shape through some ludicrously-strong material, gravity on the inner edge would still hold you against the surface.
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### Author:  [@eburacum45](https://boards.straightdope.com/u/eburacum45)
#### Post date: [March 18, 2022, 7:47pm UTC](https://boards.straightdope.com/t/donut-shaped-planet/961249/66 "2022-03-18T19:47:39Z")
> [@Sage\_Rat](#):
>
> I would probably expect the planet to be spinning inline with the Sun so the inner part of the ring would be permanently fairly dark? The ice ring should probably be carried through the whole inner section.
I did post this earlier, but you might be interested in this link.
[http://www.aleph.se/andart/archives/2014/02/torusearth.html](http://www.aleph.se/andart/archives/2014/02/torusearth.html)
Sandberg analyses three different scenarios;
zero axial tilt, 23 degrees (like Earth) and 45 degrees. My image depicts the 23 degree case.
Two different mass options are considered, one with a day length of 2.84 hours and one with a day length of 3.53 hours. This is very fast rotation, but not fast enough to eliminate gravity in either case.
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