Considering a world where the globe has two orbiting bodies at the opposite sides. They would preferably orbit around the equator. The nature of these bodies is linked to the magic system of the world, but can be simplified for this question so that other one is contributing heat and other one is contributing lack of heat (coldness).

I want the equator area to suffer from drastic and relatively fast temperature changes which make the surface inhabitable. However, getting closer to the poles it should be gradually more habitable, eventually having mild and comfortable climate that allows for agriculture. Earth-like weather phenomena such as storms, winter etc are fine as long as they allow for human-like civilizations to exist.

Preferably the temperatures on equator area would change from very cold to very hot as the bodies orbit it so that when the heat providing body is over certain location, the temperature would be at its hottest (~100C). Then, as the orbiting body continues forward, the temperature starts to decrease and when the cold providing body comes around, the temperature would eventually drop to the low values (~-100C). Hopefully the whole cycle would be few weeks long and when neither of the bodies are straight above a location, the temperatures could moderate to human tolerable range.

Currently, I'm thinking that the orbiting bodies would be smallish compared to the globe, and closer to it than other celestial bodies. As they radiate the heat/lack of heat the dispersion effect would be bit similar what happens with sunlight on earth: polar areas get lower concentration because of the angle the rays reach it, that's why the temperatures and climate are milder there. Bit similar effect would happen on the equator when the orbiters are not directly above a location. Some of the radiation from both bodies would reach the ground and temperatures are affected by both of them. When the orbiter is on the other side of the globe, no radiation would reach the opposite side (blocked by the globe).

Assuming otherwise nearly earth-like planet would the setup be possible?

  • Could the planet be reasonably sized, preferably smaller than earth with at least one continent that spans from near pole (habitable) to the equator (inhabitable)? Idea is that sea could not be buffer between inhabitable and habitable area.
  • Would the climate situation on equator totally mess the climate for the whole planet?
  • Is the cycle of couple of weeks possible, considering things like atmosphere, possible seas and ground heating/cooling fast?

If these are not possible, is there changes to the setup that would allow it?

Other limitations/notions:

  • Other celestial bodies such as sun(s), moon(s) etc can exist or not exist in a way that would make the setup possible.
  • Physical nature of the two orbiters can be hand waved to "just a magical energy source with no mass or gravitational effects" if necessary.
  • Min/max temperatures are not set in stone, but should be outside of something that normal human and most flora/fauna can tolerate for any extended period without specific gear/magical support.
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    $\begingroup$ There is no cold as such. Cold is simply "less warm". There cannot be cold-carrying radiation. To put it otherwise, Earth has a source of warmth (the sun) and all the rest of the sky is a sink in which heat is dissipated; you cannot have a body colder than the cold dark space. $\endgroup$ – AlexP Jun 10 '17 at 21:26
  • $\begingroup$ In the setup that should be tied to the magic system (inserting quite a lot of hand waving here). Basically, magic has two sides, one that causes thermal motion in particles and one that slows down the thermal motion in particles. And whatever else it does. $\endgroup$ – Mer Jun 10 '17 at 21:32
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    $\begingroup$ If the source of cold is magical then how can muggles like us calculate its effects? The basic rule of magic is that you must make up the rules, stick to the rules, and let the reader have a sporting chance of grasping the rules. Everything else is possible. So yes, if there is a magical source of coldness then the setup is possible, because with magic everything is possible. $\endgroup$ – AlexP Jun 10 '17 at 21:43
  • $\begingroup$ Yes, the source of the heat and cold are magical, but the temperature effects (high speed fluctuation on the equator) would be physical responses, and what I'm trying to think here if the whole climate system of the planet would be totally messed up assuming such drastic things happening. I considered leaving the source of the temperature fluctuation out of the question, but thought that it would cause other problems answering-wise. $\endgroup$ – Mer Jun 10 '17 at 21:57
  • $\begingroup$ The size question seems distinct from the temperature questions. Maybe split this question into two? Once you get an answer on the size question, you could include it as a constraint in the temperature question. $\endgroup$ – Brythan Jun 10 '17 at 22:05

You could have the two object follow two different polar orbits that do not quite intersect, at the same speed, separated by one orbit's time.

Polar orbit

This way, their respective areas of influence will never intersect in the Equatorial and Tropical areas, but will (neutralizing reciprocally) in the polar zones. The middle ground will be alternately burned and freezed, except in the very narrow strips between the two areas; these strips will slowly rotate, so that you can't settle them permanently.

Any given area will be burned, then frozen two hours later, left to thaw for eight hours, then the cycle will repeat. If the cold object precedes the hot one by one orbit, then the eight-hour period will be of cooling after a four hours freeze/burn.

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    $\begingroup$ Note that this depends on the objects being in a quite low orbit. With the planet smaller than Earth, low orbit becomes really low. Watch out for atmospheric drag. $\endgroup$ – a CVn Jun 11 '17 at 15:23
  • $\begingroup$ Thank you for your answer. I'll definitely consider this sort of approach too. It does offer bit different "reality" from narrative point of view. $\endgroup$ – Mer Jun 11 '17 at 16:40

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