Fox With A Shotgun, on 04 October 2017 - 06:09 PM, said:
But those can actually happen. I mean, if you had a world with a really thin atmosphere with hardly any greenhouse gases, you can theoretically have a tundra world closer to the star than a continental one.
A black hole, though? That thing doesn't even emit thermal radiation XD It sucks it in!
well it would depend on the distances involved I suppose. figure a continental world would be around earth orbit range (assuming a type G star) so the tundra world being inside of that orbit would be getting more sunlight from the star which would make it more likely to melt any ice that may have been there, assuming enough of an atmosphere that wouldn't cause it to subline directly to a gas. it would be like if mars and venus swapped orbits. all the ice on mars would melt due to higher temps from it's new orbit. I can see a desert world or an ocean world inside a continental world orbit but I don't think you can hit the lower temps for a tundra world in those conditions.
I suppose if there was a tidally locked thinner atmosphere world the ribbon between the day/night side could have a tundra environment between the melting of the ices on the edge of the dark side by whatever heat transfers from the light side. but not enough to classify the whole world that way I wouldn't think. only other scenario that might work would be a bigger tidally locked world with a thick atmosphere to transfer heat to the dark side to melt the accumulated ice there to some degree and make it tundra-ish for that half of the planet?
but yeah no way a black hole should have anything habitable around it- unless the planet hitched a ride on a star the black hole is about to eat- which isn't the case there.