Still working on that world with with a 93% ocean covering. My star Xat is 1.71 LSol, and my planet Jasmi orbits at 2.14 AU. I've been warned that the resulting apparent brightness of about 37% Sol from Earth may halt my world's evolution at the dirty snowball stage; is this necessary?
If so, is there a way to bring my planet to Earth-like or slightly colder temperatures without brightening my star?
I'm hoping to bring my world to a point where it has a band of persistent hurricanes around the equator/tropics/subtropics, or at the least, Nor-easters.
I'm told that Nor-easters would be very difficult to sustain, because I don't have enough land mass to dry out my air columns and mix cool dry air with hot humid air. The only way to change that would be to dramatically change my world map, which I don't want to do. So that leaves me with just a way of heating up my world a bit more.
Based on the answers to a prior question, I can generate heat on and in my planet in a few ways: radiation from Jasmi's core, solar radiation from Xat compounded by a greenhouse effect, frictional heating from incoming meteoroids, and tidal flexing from Jasmi's large moon. As mentioned, the distance from Xat means that it gives Jasmi about 30% of the radiation that Sol gives Earth.
The atmosphere I'm working with is 1.33 Earth atmospheres at the surface--by mass: 67% N2, 16% CO2, 15% O2, 1% CH4, and the remains made up of NH3, H2, Ne, O3, and He. Obviously if I keep this atmospheric composition I'm going to have problems with ocean acidity. I just threw this together and I'm expecting it to change; I just wanted to induce a high greenhouse effect. I could tinker with it by decreasing the CO2 and increasing the N2 and/or CH4.
Tidal flexing would maybe generate some more geological activity, but it wouldn't be incredibly significant.
I could hand-wave away the temperature problem by increasing the amount of radiation from the planet's core, but the distance from the star sets a limit on just how much radioactive material I could put in there without looking too implausible.
I'm concerned about putting an asteroid belt too close to my planet's orbit, because
- shouldn't my planet have cleared its orbit?
- I want my civilization to have as few barriers to space exploration as possible. But the amount of frictional heating I'd need to make up for my lack of solar radiation would be...significant.
Thanks for your help!