Eyeball Planets

[ysabetwordsmith]

Tidally locked planets tend to have very different conditions on the hot and cold sides.  This isn't a new idea, but the nickname is new and amusing.  It comes from the circular pattern of zones that can make a bullseye design.  This can have various configurations depending on how close the planet is to its sun.  The article includes several illustrations to show how they might look.

I would love to write this kind of setting.  It sounds like so much fun.

Comments

[siliconshaman]

Hmm.. they'd have a perpetual weather system too.. the air circulation would be as fixed as the planet, without rotation. There would be a storm in the 'eye' of the planet, and somewhere round the twilight zone it would rain forever, as the hot wet winds hit the cold air.

Come to think of it, coriolis forces would cause the clouds to form eyelids at the upper latitudes.

Well ...

[ysabetwordsmith]

With such extremes, there would be permanent drivers of weather. I think it could go different ways, though:

* Some planets would probably evolve a relatively stable set of weather systems in different places.

* Others would be prone to violent weather roaming all over the place.

This would likely depend on the type and amount of atmosphere along with the amount of heat received from the sun.

Less atmosphere and/or heat would mean less churn. More atmosphere would mean more church due to having more space to move around in, while more heat would drive the whole system with greater force. It would also depend on the amount of water (or other liquid) available. Less liquid, less churn; more liquid, more churn.

Another possible driver of erratic weather would be volcanic action. (On a dark side covered in ice, then ice volcanoes are yet another option.) If the planet has active tectonic plates, then volcanoes on the dark side could create a whole different ecosystem there, much as like the black smokers undersea have done here. You could actually have a first-contact scenario if a different sentient species arose on the cold side and the hot side.

And that's just with things we already know about. Eyeball planets might devise their own way of passing energy around, that we haven't seen here because Earth doesn't need it. But we do have analogs: consider certain systems for mass transfer of biological material from water to land (salmon runs) or land to water (herd animals drowning during migrations).

Re: Well ...

[(Anonymous)]

Atmo or hydrosphere rivers, like we used to use for trade? Heat rises, cool sinks would still move some things...

As would moons...

Re: Well ...

[ysabetwordsmith]

Those seem likely.

Really, you're just looking for energy inputs and stuff to move. Heat from the sun, geothermal, tectonic pressure, thermohaline cycle -- there are all kinds of options.

It is dead certain that eyeball planets will have a batch of standard mobilizations that we haven't thought of because they don't happen here. How would someone who only knows freshwater understand a thermohaline cycle?