🧐 It has been over twenty years since it became apparent that the Universe is full not only of red-dwarf stars , but also of rocky planets orbiting said stars .

The scientific consensus since then has become that these worlds are relatively hostile to life , and thus are not suitable candidates for future inhabitation . The reasons for this are varied , and include environmental factors such as extremely intense radiation regimes , inadequate volatile resources , and inadequate atmospheric densities .

There are however , several significant underappreciated mitigating factors which could potentially moderate the abovementioned negative ones , and result in these particular exoplanets actually being not only survivable , but permanently livable as well .

The foremost factor regarding the above is the directionality of the hard radiation given off by red-dwarf stars . Most of this is emitted in the poleward latitudes of these stars , and thus does not collide with the planets orbiting in the plane-of-the-ecliptic of these bodies . The second most impactful (and surprising) factor is the likely prevalence of at least some atmosphere on many of these worlds , this resulting from both robust and near-eternal volatiles replenishment regimes , and also moderately strong planetary magnetic-fields . The tertiary moderating factor is the likely presence of constantly circulating atmospheres evidencing planetary superrotation , and thus taking excess thermal energy from the starlit sides and redistributing it to the unlit sides of these planets . Lastly , tidal-heating might have a significant effect upon the thermal regime of these worlds, this then affecting their overall abilities to maintain planetary dynamos , and by extension , planetary magnetic-fields as well .

There are also a myriad of lesser factors which could potentially affect both the usability and the hhabitability of the abovementioned planets , but the number of parameters and synergies involved is far to large for any facile generalizations .

Edited December 12Dec 12 by Professor-M
Esthetics

1 hour ago, Professor-M said:

The foremost factor regarding the above is the directionality of the hard radiation given off by red-dwarf stars . Most of this is emitted in the poleward latitudes of these stars , and thus does not collide with the planets orbiting in the plane-of-the-ecliptic of these bodies .

Still needs to be quantified, though, since most is not all, so the question is how much radiation is involved?

I am curious about the propensity and possibility for worlds evolving life naturally and how similar or different to life as we know it but I am not interested in the potential for human colonization. I think interstellar colonisation is an attractive fantasy - a good topic for imaginative fiction - but very not-realistic. It is not a reasonable goal or motivation, especially in the absence of the technological and economic capabilities needed.

Even if we were close to the technological capabilities required for sending people there such a planet would have more attraction as something for people to study more directly - but not colonise. I think if we do achieve the technological and economic capability to send people to the worlds of other stars with enough equipment and resources to establish a colony we won't need planets to colonise for any species survival reasons. Artificial habitats in space, difficult as those are, seem more reasonable, offering greater potential, because they can be almost anywhere and be made with just right conditions inside for humans and biosystems that support human life.

Assuming it is technologically and economically feasible to send people (unlikely) an exo-planet with life might rate a mission for studying and sampling using probes and rovers, from the safety and comfort of a space habitat - but even uncrewed robotic missions seem extraordinarily difficult and expensive. Sending people would be much more so. I hesitate to say intrinsically impossible, just impossible in practice.

The value of such a world will be diminished by attempting to colonise it even if not involving remaking the native biology (ie kill and replace or genetically modify) to be more human and Earth species friendly. It seems rather primitive and short sighted to me to sacrifice that extraordinary scientific opportunity to study alien biology for such a self indulgent goal as conquest, terraforming and land ownership.

I also suspect any planet with life will have a low probability of being biochemically compatible with terrestrial life. Even if it has an atmosphere roughly equivalent to Earth in Nitrogen, Oxygen, water vapour and etc (such atmosphere here is a product of life) it is optimistic to imagine humans could breathe unfiltered air safely; living biology is extraordinarily inventive when it comes to allergens, poisons, diseases and parasites. For most of Earth's living history this planet didn't have atmosphere humans could safely breathe.

I expect it will be detection of bio-signatures that finds evidence of life beyond our solar system, probably with a lot of arguing about the validity. We may yet find evidence of life within this solar system and obtain living samples (not likely but possible) - and go on to determine if such life originated and was spread from Earth, emerged independently or is indicative of interstellar pan-spermia.

Edited December 15Dec 15 by Ken Fabian