[Space] What is the 'Gaia' type of garden worlds like? ('Habitability 9').

[Daigoro]

Originally Posted by Varyon

*I've opted to have Hope in my space opera setting indeed be a planet with twice Earth's mass (and 1.25G). I haven't yet decided if I'll have it orbiting a K-dwarf like in the paper, a yellow dwarf, or something else entirely, however.

You might be interested to note that Trappist-1c, with 1.17 Earth density, 1.08 Earth radius, and 1.38 Earth mass, calculates to 1.25 g.

[Varyon]

Originally Posted by Daigoro

You might be interested to note that Trappist-1c, with 1.17 Earth density, 1.08 Earth radius, and 1.38 Earth mass, calculates to 1.25 g.

Won't work for Hope (too far away, star too unlike Sol, too much radiation, too young, etc), but might be an option for the hostile aliens* of the setting. Hope isn't going to be in any star system that actually exists in our universe - in fact, none of the inhabited systems (aside from the Sol system, of course) are going to exist in our universe. I'll probably end up buying Space to properly build my setting, but the current plan is to basically make up a bunch of G5sd stars, which I assume will have light output similar enough to Sol for Earth plants to grow in their hospitable zones. Human technology can only breach the barrier between realspace and hyperspace around the astropause of such stars, which is why they are the only ones that get colonized. The alien bioships don't have such a limitation, so they could colonize the Trappist system or similar. The aliens are also incredibly hardy when it comes to resisting radiation, so that won't be too much of an issue (I'll ignore the "possibly still molten" part of the problem with the Trappist planets).

So, thanks for that. I was originally going to basically ignore their "home system," but Trappist sounds too tempting to ignore.

*Actually the descendants of breeding-capable** bioroids created by an immortal mad scientist from Earth. They start as grubs and can differentiate into a wide variety of forms, most of which aren't sapient. Their bioships are actually one such form. I did mention this was Space Opera, right?

**Which apparently means they aren't bioroids in GURPS-speak. Some of their breeding is actually parthenogenesis, with the bioships making genetically-identical individuals for crew, but sexual reproduction is more common on colonies.

[Flyndaran]

Originally Posted by Daigoro

You might be interested to note that Trappist-1c, with 1.17 Earth density, 1.08 Earth radius, and 1.38 Earth mass, calculates to 1.25 g.

M8 stars are almost certainly not going to have photosynthetic life. Almost no light in the visible spectrum. Sad, since it seems like rocky "earth-like" planets may be much more common around red dwarfs than yellow stars like ours.

High gravity, possible dense atmosphere, and thick oceans could still allow one or more of Trappist's planets to have black smoker or radiation eating deep rock inhabiting type life.