Just thinking if it is possible to have a Fire-Freeze Planet?

A planet with permanent Ice cover on one hemisphere while a hot terrain on the other side of it. A planet that may have moderate equator while the hemispheres are extreme.
I am talking about Temperature Here.

Please Help!
I am developing some kind of game based on this.

Update: -

  • A planet without day-night cycle if possible maybe include.
  • The planet should be literally burning on one side while super frozen on another side
  • $\begingroup$ Is this a planet with an Earth-like atmosphere? $\endgroup$ May 17, 2017 at 4:50
  • $\begingroup$ Welcome to WorldBuilding! If you have a moment please take the tour and visit the help center to learn more about the site. Have fun! $\endgroup$
    – Secespitus
    May 17, 2017 at 7:14
  • $\begingroup$ @JoeKissling not really $\endgroup$ Jul 29, 2017 at 3:40

4 Answers 4


A tidally locked planet, close to the star will have extremes of heat on the sun-side, and extremes of cold on the other. There would be a temperate belt right at the edges, but I doubt that life more advanced than small multicellular globules could develop.


For example, Mercury's Sun side reaches 427 °C (800 °F) and it's far side dips to −173 °C (−280 °F).


  1. Without a large moon to help regulate the planet's orbit, tidal locking can only happen near to the star.
  2. Mercury has 3:2 locking. A planet with 1:1 locking would have even greater temperature extremes.
  • 7
    $\begingroup$ The temp extremes on Mercury are primarily due to its lack of atmosphere, so be careful when using it as an example. $\endgroup$ May 17, 2017 at 5:04
  • 1
    $\begingroup$ It's also important to note that it wouldn't be the planet's equator that would be temperate (as in the question), but rather its terminator. $\endgroup$
    – Phiteros
    May 17, 2017 at 5:13
  • $\begingroup$ I found this (arxiv.org/pdf/1405.1025.pdf) when googling "atmosphere on a tidally locked planet". It's about when the Earth becomes tidally locked because of the Moon. $\endgroup$
    – RonJohn
    May 17, 2017 at 5:21
  • 3
    $\begingroup$ @RonJohn With an earthlike atmosphere there will be very good mixing of the atmosphere, reducing the temp extremes. It is even mentioned in your paper. "The presence of an atmosphere can help distribute the heat across the planet, equalizing the temperatures." Our nice thick atmosphere is an excellent heat exchanger. $\endgroup$ May 17, 2017 at 5:45

Let's assume you want some Earth like features (such as a day/night cycle)

In that case, you want an elongated orbit and a strongly tilted axis of rotation, such that 'summer' for one hemisphere is a long way from the sun, but for the other it is near the sun. So one hemisphere gets an extreme, if short, summer, whilst the other has a cold, long 'summer'.

(Bear in mind that we don't need that much of an elongation in orbit)

This still wouldn't be enough; we'd need a way of storing heat in the 'hot' hemisphere to get it through it's long winter, probably via shallow seas, and the 'cool' hemisphere could have extensive land/highlands with glaciers to reflect heat, furthering the North-South divide. This may bear some resemblance to Earth in the Mesozoic, with a large supercontinent (Gondwanaland) over the south pole and not so much land in the North. Even on earth today, the presence of Antartica means that the Northern hemisphere is ~2K warmer than the South.

So - a combination of orbital features, land mass distribution, albedo feedback and handwaving should do it.


If you want to go with something different, what about a geological explanation. One side is highly volcanically active. Maybe it's due to a fractured crust on that side, the result of a collision with another body early on in its formation, causing a wound that never "healed", but instead remains highly geologically active. Or perhaps the core of the planet is shifted for some reason to be closer to one side of the planet than the other, causing the crust on that side to be thinner and more active. The other would be relatively stable, geologically speaking, but because of all the volcanic ash in the air, it is in a sort of nuclear winter, where little to no sunlight penetrates the cloud cover, causing the other side to be cold. A literal fire and ice planet.


You want a hot Eyeball planet. Tidally-locked (like mentioned above), with a thin atmosphere to avoid efficient heat redistribution and not too much water.

See here or here.

There can be some variety too. Here is an image of the possible climates on Proxima b (from climate models). Details here or here.

enter image description here


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .