Speculative Astronomy - Warm South Pole?

[Mosaic]

Could you - without resorting to "magic!" - have a planet with a cold North Pole and warm South Pole? Oh, and have it be livable by standard humans and animals.

If the axis of rotation were always pointed at the sun (instead of being fixed), you'd get a perpetual summer South and a perpetual winter North. You'd still have regular summer/winter length days and nights, assuming the axis is still tilted and the planet is still rotating. You might have to worry about long-term over heating and over-cooling, but the main effect I see here is it always being summer in the South and winter in the North.

So, if seasons are normally caused by a fixed axis of rotation pointing in different directions relative to the sun at different phases of the planet's revolution around the sun... are there any other ways to cause seasons? What about plain old distance from the sun? If the planet had an oval eliptical orbit and was closer to the sun for a while and farther from the sun for a while... could that mimic seasons? Focusing on the Northern Hemisphere, would that result in a "cold winter" when the planet was farther away and a "warm winter" when it was closer? The angle of the light would still always be "winter" but I wonder if the amount of additional heat would be enough to make "warm winter" almost like summer. (The Southern Hemisphere, on the other hand, would probably go from "warm summer" to "incredibly hot super-summer" and might be pretty desolate.) The sun would appear larger in the sky during "warm winter"/summer than it would during "cold winter." I was going to say that eclipses would be interesting because sometime the moon would be big enough to block the sun and sometimes not... but if the orbit of the moon is perpendicular to the axis of rotation, there would never be a time when it passes between the sun and planet, would there?

The other effect would to have 2 winters and 2 summers per full revolution, so the faux seasons would be really quick. (Maybe too quick for much change to happen in between?) But what if 1 revolution took the equivalent of 24 months? They might measure 1 "year" as Mid-Winter/aphelion to Mid-Winter/aphelion, even though they would be at opposite sides of the sun. One winter you'd see one set of constellations and the next you might see them slightly differently (although a 2AU change in location probably isn't enough to change constellations. But other planets might look a lot more wobbly!).

So, would any of that work? Would that give the Northern Hemisphere a winter/summer experience and an always-cold North Pole, and the Southern Hemisphere a summer/super-summer experience and an always-hot South Pole? Would the planet still be livable (at least in the North)? Any other bizarre repercussion or side effects?

Thanks!

[Staffan Johansson]

I'm not sure about the effects on temperature/seasons, but a strongly elliptic orbit would mean that the time spent closer to the sun would be shorter (at least under Newtonian physics, and in general Starfinder matches those).

Basically, as a planet comes closer to the Sun, it is accelerated more (because of stronger gravity) and thus moves faster. If you draw a line between the planet and the Sun, the area "swept" by that line during a given amount of time is constant no matter where in its orbit the planet is.

It's explained in more detail here, though I figure the animation a few pages down is enough to illustrate the point.

I'm also not sure about non-fixed axes of rotation. Changing an axis of rotation generally requires energy (that's how gyroscopes work), so keeping the south pole constantly turned toward the sun would require a system with continual energy input.

[Simeon]

A somewhat tilted axis pointing the south pole toward the sun would likely result in a warm south pole. That would make it, effectively, tidally locked but along a different axis.

[Ellias Aubec]

What you described there was Verces, with a desert on the side facing the sun, frozen wasteland on the other side and a small habitable zone between them.

[The Sideromancer]

Note that if your magnetic poles line up with the rotational poles (like most planets), you can expect a lot of auroras and other solar effects at the south end since the blind spot of the magnetic field lines up with the direction the solar wind is coming from.

I suppose another possibility is to have a normally-aligned planet with geography making the heat transfer asymmetric (e.g. normally heat moves to the poles via air currents and leaves through deep water currents, so if the south has a lot of ocean ridges disrupting the currents it might be warmer than the north)

[avr]

Angular momentum prevents the south pole being pointed at the sun constantly. The amount of magic or other energy you'd need to contradict that is mind-boggling.

A source of heat at the south pole might work. Starfinder shouldn't have a problem with a mini-sun on the surface, or perhaps below the surface with winds blowing out. The mini-sun might be a gate to the plane of fire, some artifact which generates lots of heat, or maybe a giant borehole leading down to the mantle.

A tidally locked world has temperature of areas mainly determined by where they are relative to the sun. The rotational poles will be on the twilight band and a few mountains could trap the suns rays or deflect them depending on where they are.

[MasterZelgadis]

A tilted polar axis should be enough to have a warmer south pole. At least in one season. Note that temperature differences between seasons would be huge (with a warm south pole you would have an exceptionally cold north pole, but that would switch in summer/winter.

[Arutema]

MasterZelgadis wrote:

A tilted polar axis should be enough to have a warmer south pole. At least in one season. Note that temperature differences between seasons would be huge (with a warm south pole you would have an exceptionally cold north pole, but that would switch in summer/winter.

With a sufficiently long year, this could get interesting. Yes, the south pole is warm this time of year, which will last another 100 or so Golarion standard years, but then it will become uninhabitably cold for another 100 standard years, while everyone has migrated to the north pole.

[Metaphysician]

It probably wouldn't work in terms of realistic geology, but you could *maybe* shift the temperature of the south pole up via an excess of volcanic activity. I'm thinking "the mantle is basically broken open" mind, so it would almost certainly make the area uninhabitable for other good reasons.

[David knott 242]

If you are not insisting on having a cold north pole, you could go with a planet with little or no axial tilt that is so hot as to be uninhabitable anywhere but at the poles. With limited scientific knowledge and no method for surviving the transit through the non-polar areas, nobody on that world would know whether the other pole is hot or cold.

[BigNorseWolf]

Ocean currents. They do weird things.

[Yqatuba]

Well Traxius is already kinda like this.