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Author Topic: Looking for a way to have the axis point at the star year-round.  (Read 384 times)

OldKingSol

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I'm working on a specific simulation for a fictional solar system I'm making, and one of the requirements for the primary inhabited planet is that its northern axis leans toward the primary star year-round. It's not a full 90 degree tilt, but about 75-85 degrees, so the southern hemisphere would be permanently iced-over while the northern hemisphere would be perpetually hot and dry. Is there a way to accomplish this in US2? I looked through some threads about tidal locking, but that didn't quite do it.

Any help would be greatly appreciated. Thanks for your time. :-)

electricpants

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Re: Looking for a way to have the axis point at the star year-round.
« Reply #1 on: July 21, 2017, 09:56:28 PM »
Yes, you press the 'Tidal Lock' button. (Haven't played the game for awhile, so i forgot what tab it's in)

But you can't have a planet that perpetually faces the star with any axial tilt, except 0 (180 would make the planet rotate, because it would be spinning in the opposite direction of it's orbit, giving it a day-night cycle, which tidal locked planets don't have).

It's because, "simple answer, Tidal locking with solid bodies by definition, the same side of the planet or moon faces the object it orbits all of the time. Obliquity doesn't make much sense if the planet's primary rotation is in sync with it's orbit around an object. (Tidal Locked planets do in fact rotate). So, it seems counter intuitive that a planet could have a high obliquity and at the same time, be tidally locked to the object it orbits." (Answer from https://astronomy.stackexchange.com/questions/16499/can-a-tidally-locked-planet-maintain-an-obliquity)

Physics_Hacker

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Re: Looking for a way to have the axis point at the star year-round.
« Reply #2 on: July 27, 2017, 05:38:30 PM »
Yes, you press the 'Tidal Lock' button. (Haven't played the game for awhile, so i forgot what tab it's in)

But you can't have a planet that perpetually faces the star with any axial tilt, except 0 (180 would make the planet rotate, because it would be spinning in the opposite direction of it's orbit, giving it a day-night cycle, which tidal locked planets don't have).

It's because, "simple answer, Tidal locking with solid bodies by definition, the same side of the planet or moon faces the object it orbits all of the time. Obliquity doesn't make much sense if the planet's primary rotation is in sync with it's orbit around an object. (Tidal Locked planets do in fact rotate). So, it seems counter intuitive that a planet could have a high obliquity and at the same time, be tidally locked to the object it orbits." (Answer from https://astronomy.stackexchange.com/questions/16499/can-a-tidally-locked-planet-maintain-an-obliquity)

They don't mean tidal ocking, they mean axial locking, essentially. Meaning the axis of the planet could precess at the same rate as the revolution of the planet, making the axis always point toward the star. Our axis takes (if I remember correctly) 23,000 years to make one full precession, but if it only took a year, depending on the position of the earth in its orbit when first made to rotate that way, either the north or south pole would be in constant light or dark forever, even if we retained out 24-hour day.
There is currently no way to do this but it would add a layer of realism to simulations, even involving non-fictional ones, as even a 23,000 year precession cycle can effect whats day and whats night on a certain date in this or that century. Also, I think many people would have a fun time setting both the rotation and precession to be really fast and watch as the planet acts like a top XD

Me

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Re: Looking for a way to have the axis point at the star year-round.
« Reply #3 on: July 30, 2017, 02:01:43 PM »
Ok i kinda knows that you want several axis to rotate, and that's certainly possible in Universe Sandbox2, from what i know, i found out by tweaking these parameters ringed in red you can make several axis rotate, but you have to tast in random numbers to make your following descision. Unfortunately, the other axis have the same rotation speed as the primary rotation axis  :-\

electricpants

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Re: Looking for a way to have the axis point at the star year-round.
« Reply #4 on: August 02, 2017, 09:19:51 AM »
Our axis takes (if I remember correctly) 23,000 years to make one full precession, but if it only took a year

Correct me if I'm wrong, but I don't think planetary axis' can precess that fast.

Physics_Hacker

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Re: Looking for a way to have the axis point at the star year-round.
« Reply #5 on: August 08, 2017, 08:37:17 PM »
Our axis takes (if I remember correctly) 23,000 years to make one full precession, but if it only took a year

Correct me if I'm wrong, but I don't think planetary axis' can precess that fast.

Fairly sure thats the right number, only in a few thousand years Polaris will not be the north star.but I'll look it up...

I was close, its 26,000 years, so yeah, they can and do..

electricpants

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Re: Looking for a way to have the axis point at the star year-round.
« Reply #6 on: August 09, 2017, 12:07:08 PM »
Our axis takes (if I remember correctly) 23,000 years to make one full precession, but if it only took a year

Correct me if I'm wrong, but I don't think planetary axis' can precess that fast.

Fairly sure thats the right number, only in a few thousand years Polaris will not be the north star.but I'll look it up...

I was close, its 26,000 years, so yeah, they can and do..

Well, I meant an axis that precesses every year.
I guess it's my fault for quoting that entire part, though. :-\

Physics_Hacker

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Re: Looking for a way to have the axis point at the star year-round.
« Reply #7 on: August 12, 2017, 04:50:13 PM »
Our axis takes (if I remember correctly) 23,000 years to make one full precession, but if it only took a year

Correct me if I'm wrong, but I don't think planetary axis' can precess that fast.

Fairly sure thats the right number, only in a few thousand years Polaris will not be the north star.but I'll look it up...

I was close, its 26,000 years, so yeah, they can and do..

Well, I meant an axis that precesses every year.
I guess it's my fault for quoting that entire part, though. :-\

Ah, I understand. And while it may be unlikely, maybe the planet is heavier on one pole than the other and so the gravity of the star pulls on it to make it stay? Maybe it suffered an impact that made this take effect?There are some situations where it could happen...