> a good chunk of the action of my work-in-progress Starter Pack is set on a terraformed Earth-mass moon orbiting a Hycean planet of roughly Neptune's mass orbiting its star in the triple phase zone for water (i.e. where water can exist as ice, liquid, or vapour). The moon in question has spin (presumably it got kicked off by a collision with another proto-moon while the moon system was forming), so a magnetosphere, and tides to keep plate tectonics going--but this time tides from its primary planet, not a large sub-moon of its own.
This makes me so curious as to the approach he's taking with this next book, in terms of the biology of creatures native to these bodies (if they exist). I've been thinking a lot about the approach Andy Weir took for the Eridians: start with the physical characteristics of the planet and reverse-engineer biology that was likely to be viable under those circumstances. As someone who typically writes hard sci-fi, I can't help but be drawn to that approach — too many worlds and environments are designed around the characters and it ends up feeling totally incoherent.