[Space] Gliese 581

dataweaver · 10-04-2010, 03:30 PM

True; but they aren't necessarily so low that we need to resort to handwavium to get a reasonably habitable world for the purpose of Space roleplaying.

Note that if the world in question is terrestrial, its atmosphere is more likely to hug the surface, with pressure dropping off more rapidly than on Earth. As such, solar radiation won't have to penetrate as many miles (or km, if you prefer) to get to the surface. This is a mixed bag: on the one hand, this could potentially mitigate the effects of cloud cover in terms of photosynthesis; OTOH, that also provides less atmospheric shielding against solar flares. (OTGH, I suspect that the planet's magnetosphere is the primary defense against charged-particle radiation; and while the planet's slower rotation (assuming tidal locking) works against a strong magnetosphere, a significant iron core and the planet's larger mass would tend to work in favor of one. So even if the atmosphere is thicker at the surface (of which I'm not convinced; too many variables, not enough information), that doesn't have to mean a super-Venus.

10-04-2010, 03:30 PM	#25
dataweaver Join Date: Aug 2004	Re: [Space] Gliese 581 True; but they aren't necessarily so low that we need to resort to handwavium to get a reasonably habitable world for the purpose of Space roleplaying. Note that if the world in question is terrestrial, its atmosphere is more likely to hug the surface, with pressure dropping off more rapidly than on Earth. As such, solar radiation won't have to penetrate as many miles (or km, if you prefer) to get to the surface. This is a mixed bag: on the one hand, this could potentially mitigate the effects of cloud cover in terms of photosynthesis; OTOH, that also provides less atmospheric shielding against solar flares. (OTGH, I suspect that the planet's magnetosphere is the primary defense against charged-particle radiation; and while the planet's slower rotation (assuming tidal locking) works against a strong magnetosphere, a significant iron core and the planet's larger mass would tend to work in favor of one. So even if the atmosphere is thicker at the surface (of which I'm not convinced; too many variables, not enough information), that doesn't have to mean a super-Venus.