Dim stars, small worlds

[mike wightman]

Here is an article that may be the first step on the way to explaining all those populated planets around dim "stars" that exist within Traveller canon.

 

[robject]

Well, really, I don't think Traveller takes type T and type L stars -- brown dwarfs -- into account. Maybe Malenfant should tell us if we need worry about these.

 

[mike wightman]

More info...

I was reading an article that many brown dwarfs may be upgraded to dim red... but I can't find the article at the moment.

 

[Malenfant]

I wrote an article on Brown Dwarfs (L and T) for JTAS, but AFAIK you can only get it by subscribing to JTAS .

 

[Jeff M. Hopper]

I posted this question to the TML, but wouldn't the Brown Dwarf's light spectrum be in the deep infra-red? If it is then it could provide plenty of heat for a habitable world, but the light would be wrong for photosynthetis as we know it. Could photosysthetic life evolve under those conditions?

I can understand placing a human habitable world there, but the ecology would have to be either the leftovers of someone's terraforming or bizarre by our standards to give that world a breathable atmosphere.

 

[DED]

Who says that you need to have an ecology based on photosynthesis? If the planet is warm enough that it isn't a just a block of ice, there's no reason that chemosynthesis couldn't be the planet's foundation for life. It's going on down in the deep dark ocean trenches here on Earth. Of course, the planet needs to be geologically active.

 

[Ran Targas]

^ Or what if the worldlet is inside the gas giant's magnetic field (similar to Io) and the lifeforms tap the tremendous amount of radiation as an energy source? Could be an environment where crystalline or metallic lifeforms could thrive, yes?

 

[mike wightman]

Hmm, crystalline or metallic lifeforms?

On a moon around a gas giant, getting their energy from magnetic fields and radiation...

What a great idea, please consider it borrowed

 

[robject]

How about lifeforms which developed on a very small (size S?), unstable, very thin atmosphere, tectonically active world, were flung into space -- either from the planet's erupting gas vents, or as the world was bombarded by debris from space -- and adapted to the mineral-rich, vacuum environment of an asteroid belt. They survive by eating and hoarding water and minerals gathered from asteroids in their vac-tite, radiation-safe, translucent shell. They move by squirting very brief jets of water vapor.

 

[Golan2072]

Originally posted by Jeff M. Hopper:
but the light would be wrong for photosynthetis as we know it. Could photosysthetic life evolve under those conditions?

Depends on the pigment; Chlorophyl and similar pigments used in photosynthesis absorb visible light. In an IR-intensive world, an IR-absorbing pigment (which, IIRC, is chemically possible/existant) would eventually evolve into a photosynthetical one.

And chemosynthesis, mentioned here, is an interesting option as well - imagine sophonts who "eat" sulfur and even have sulfur deposits insiode their bodies instead of fat as an energy reserve (some bacteria do so).