I think many planets may have life below the surface. The hot core of planets behave like a heat reactor. Somewhere between the hot planet core and cold planet surface there should be a balanced temperature a mix. That mix may have a temperature of 0-37C.
We should be able to do the same on earth first. Where's our underground Polar habitats? I personally see Musks' Boring company" stuff as interesting as the rockets, I wish it where cheaper to build cities/tunnels underground.
I think many planets may have life below the surface. The hot core of planets behave like a heat reactor. Somewhere between the hot planet core and cold planet surface there should be a balanced temperature a mix. That mix may have a temperature of 0-37C.
https://en.m.wikipedia.org/wiki/Planetary_core