# Questions about tidally locking a fictional planet to its star **URL:** \ **Category:** Factual Questions\ **Created:** [July 3, 2016, 11:37am UTC](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993 "2016-07-03T11:37:42Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![Askthepizzaguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askthepizzaguy/32/9405_2.png) [@Askthepizzaguy](https://boards.straightdope.com/u/Askthepizzaguy)\ **Post date:** [July 4, 2016, 1:12pm UTC](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993/21 "2016-07-04T13:12:36Z")
I’m loving all the contributions to this thread so far. For the purposes of the story I’ll probably have to find something different to work with, based on these responses, but it’s giving me a lot to think about. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [July 4, 2016, 1:36pm UTC](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993/22 "2016-07-04T13:36:02Z")
Just keep in mind you can rely a little on magic, I understand you want to keep it reasonably realistic but you do have a little wiggle room. ---
**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:** [July 4, 2016, 1:55pm UTC](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993/23 "2016-07-04T13:55:19Z")
Venus’s rotation actually has a resonance with Earth: Whenever the two planets are closest together, she always shows the same face to us. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [July 4, 2016, 4:57pm UTC](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993/24 "2016-07-04T16:57:26Z")
That’s just plain weird … they don’t even rotate the same direction … but plenty of citations on the internet to back up that claim … and I always knew she was a two-faced lil’ twit … ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [July 4, 2016, 5:29pm UTC](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993/25 "2016-07-04T17:29:42Z")
> [@OldGuy](#): > > Also Steve Baxter’s Proxima takes place on a planet circling Proxima Centauri which is tidally locked. He has native life there as well as Earth people colonizing it. I haven’t checked this one, but his science is generally pretty reasonable so you probably don’t need your moon to cool things off enough for life. There have been a number of simulations of the weather for tidally-locked planets; some of them show that parts of a tidally-locked world could be ‘habitable’. which ususally means that liquid water could exist there. Some examples have a small habitable zone near the sub-solar point; others have habitable zones near the terminator, where the local sun is always on the horizon. On a tidally-locked planet with a short year the planet rotates quite quickly, so the atmosphere moves fast enough to spread the heat out more evenly across both hemispheres. Any planet orbiting around Proxima Centauri in the habitable zone would have a fairly short year, and this smearing effect could be quite significant. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [July 4, 2016, 5:35pm UTC](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993/26 "2016-07-04T17:35:01Z")
I have a suggestion which might just work: make the star absolute minimum mass and have the pair orbit another, brighter star, so the near star eclipses the farther star. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [July 4, 2016, 6:26pm UTC](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993/27 "2016-07-04T18:26:54Z")
> [@Chronos](#): > > Venus’s rotation actually has a resonance with Earth: Whenever the two planets are closest together, she always shows the same face to us. Is that a coincidence or is the Earth controlling Venus’s rotation rate? ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [July 5, 2016, 1:23am UTC](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993/28 "2016-07-05T01:23:30Z")
> [@bob\_2](#): > > I have a book, whose title i don’t remember, in which there is a planet that is being farmed for the benefit of earth, with an annual visit by freighters. The planet has an orbit/rotation the makes periods of hot dry climate and extremely cold periods. The whole population gets on a land train to move through the excessively fertile and hostile central area to the hot part. Wheelworld. by Harry Harrison, 1980. The middle volume of the _To the Stars_ trilogy. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [July 5, 2016, 1:42am UTC](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993/29 "2016-07-05T01:42:39Z")
Wikipedia has an [interesting article](https://en.wikipedia.org/wiki/Habitability_of_red_dwarf_systems) on the habitability of planets around red dwarf stars that seems relevant to the question, since [tidal effects](https://en.wikipedia.org/wiki/Habitability_of_red_dwarf_systems#Tidal_effects) are a major issue. [Previous page](https://boards.straightdope.com/t/questions-about-tidally-locking-a-fictional-planet-to-its-star/758993.md?page=1)