You design life and a system

[OceanPlanet]

Yes and there’s another poll post. (For Cha’s post, you’re correct.)

Internal structure for 1st planet.

• Crust, mantle and core
• Crust, mantle, outer core and inner core (has induced magnetosphere)
• Crust, mantle, outer core and inner core (has internal magnetosphere)

Atmospheric composition of the 1st planet

• Oxygen-rich atmosphere
• Carbon dioxide-rich atmosphere
• Methane-rich atmosphere
• Earth-like atmosphere

[aah31415 (The maker of SitF, Radiostrocity, The Lifenote and TGBing; The Second Ascended...; And just maybe a security warning come alive...?)]

If it had either methane ot co2 it would probably be very hot…

[OceanPlanet]

So, here’s the results:

1. The planet has it’s own strong magnetic field that can protect from radiation,
2. I’ll combine them into a oxygen and methane rich atmosphere.
   Pie chart for atmosphere:
   
   

[aah31415 (The maker of SitF, Radiostrocity, The Lifenote and TGBing; The Second Ascended...; And just maybe a security warning come alive...?)]

Doesn’t oxygen break down methane?

[OceanPlanet]

It’s maybe the early years of gaining methane in the planet’s history.

[aah31415 (The maker of SitF, Radiostrocity, The Lifenote and TGBing; The Second Ascended...; And just maybe a security warning come alive...?)]

Still reactions will occur as long as both gasses find themselves in the same space.

[Cha (Waluigi)]

That just means less oxygen, a lot more carbon dioxide and water from the methane reaction.

[aah31415 (The maker of SitF, Radiostrocity, The Lifenote and TGBing; The Second Ascended...; And just maybe a security warning come alive...?)]

I presume water and co2 would maintain a greenhouse effect…

[AnthropocenianAge (𝒜𝓇𝓉𝒽𝓇𝑜𝓅𝓁𝑒𝓊𝓇𝒶 𝓌𝒶𝓃𝓉𝓈 𝓉𝑜 𝑔𝒾𝓋𝑒 𝓎𝑜𝓊 𝒶 𝒽𝓊𝑔!)]

I wonder if the moon for the first planet would be possible if it was a small iron meteorite stuck/protected in the first planet’s magnetic field?

[aah31415 (The maker of SitF, Radiostrocity, The Lifenote and TGBing; The Second Ascended...; And just maybe a security warning come alive...?)]

That could work I suppose. Not sure “small moon” is just a captured meteorite though.

[AnthropocenianAge (𝒜𝓇𝓉𝒽𝓇𝑜𝓅𝓁𝑒𝓊𝓇𝒶 𝓌𝒶𝓃𝓉𝓈 𝓉𝑜 𝑔𝒾𝓋𝑒 𝓎𝑜𝓊 𝒶 𝒽𝓊𝑔!)]

This idea might still work if the first moon was the relatively intact remant iron core from a previously destroyed world.

[aah31415 (The maker of SitF, Radiostrocity, The Lifenote and TGBing; The Second Ascended...; And just maybe a security warning come alive...?)]

That would make the system’s interior already have an interesting story…

[OceanPlanet]

Well, I accept it and I have come up an idea on how the methane atmsphere may survive.
The methane is now mostly organic, coming from methanogen, a somewhat dominant bacterial group in their planet, this supply of methane will prevent it from dissepearig due to reaction with oxygen.
That is if they have life.

[aah31415 (The maker of SitF, Radiostrocity, The Lifenote and TGBing; The Second Ascended...; And just maybe a security warning come alive...?)]

You would need a heavy supply of methane to still have half of the atmosphere be it…

[OceanPlanet]

Well, I’d imagine that would about the quarter of the atmosphere of the modern day, like oxygen in Earth.

[aah31415 (The maker of SitF, Radiostrocity, The Lifenote and TGBing; The Second Ascended...; And just maybe a security warning come alive...?)]

So methane percentage in the atmosphere would decrease over time down to a certain level?

[OceanPlanet]

Yes and for plot interest, I would include the intact iron core moon.

[aah31415 (The maker of SitF, Radiostrocity, The Lifenote and TGBing; The Second Ascended...; And just maybe a security warning come alive...?)]

So that’s what you’ll go with?

[OceanPlanet]

Yes and here’s an image.

[aah31415 (The maker of SitF, Radiostrocity, The Lifenote and TGBing; The Second Ascended...; And just maybe a security warning come alive...?)]

Seems more habitable than I’d think…