Alien Life Could Thrive In the Clouds of Failed Stars (sciencemag.org) 67
sciencehabit writes: There's an abundant new swath of cosmic real estate that life could call home -- and the views would be spectacular. Floating out by themselves in the Milky Way galaxy are perhaps a billion cold brown dwarfs, objects many times as massive as Jupiter but not big enough to ignite as a star. According to a new study, layers of their upper atmospheres sit at temperatures and pressures resembling those on Earth, and could host microbes that surf on thermal updrafts. The idea expands the concept of a habitable zone to include a vast population of worlds that had previously gone unconsidered. "You don't necessarily need to have a terrestrial planet with a surface," says Jack Yates, a planetary scientist at the University of Edinburgh in the United Kingdom, who led the study. Atmospheric life isn't just for the birds. For decades, biologists have known about microbes that drift in the winds high above Earth's surface. And in 1976, Carl Sagan envisioned the kind of ecosystem that could evolve in the upper layers of Jupiter, fueled by sunlight. You could have sky plankton: small organisms he called "sinkers." Other organisms could be balloonlike "floaters," which would rise and fall in the atmosphere by manipulating their body pressure. In the years since, astronomers have also considered the prospects of microbes in the carbon dioxide atmosphere above Venus's inhospitable surface. Yates and his colleagues set out to update Sagan's calculations and to identify the sizes, densities, and life strategies of microbes that could manage to stay aloft in the habitable region of an enormous atmosphere of predominantly hydrogen gas. On such a world, small sinkers like the microbes in Earth's atmosphere or even smaller would have a better chance than Sagan's floaters, the researchers will report in an upcoming issue of The Astrophysical Journal. But a lot depends on the weather: If upwelling winds are powerful on free-floating brown dwarfs, as seems to be true in the bands of gas giants like Jupiter and Saturn, heavier creatures can carve out a niche. In the absence of sunlight, they could feed on chemical nutrients. Observations of cold brown dwarf atmospheres reveal most of the ingredients Earth life depends on: carbon, hydrogen, nitrogen, and oxygen, though perhaps not phosphorous.
But what would they eat? (Score:2)
Re: (Score:2)
WE HAVE THE MEATS
Re:But what would they eat? (Score:4, Interesting)
I see that the ACs are idiots, as usual.
The brown dwarf does not really have fusion at its core, but it does have fission. (It is heavy, and absorbs heavy atoms from the nebular cloud it forms from, which settle to its core.) This heats the brown dwarf internally, causing convection.
This supplies energy, and a weather system that will move raw materials around inside the brown dwarf. Dead microbes will be subducted deeper into the brown dwarf, become denaturated from the heat, and become raw materials. Those will be pushed up by convection.
In addition to heat, brown dwarfs DO emit light from blackbody radiation, and being pretty damned hot down there (just not enough for fusion), that is quite a bit in the visible spectrum. That means photosynthetic life can persist in the temperate layers high up.
So, what do they eat?
1) chemicals replenished by denaturation deeper inside the star.
2) Light emitted from deeper inside the star.
3) each other.
Re:But what would they eat? (Score:5, Interesting)
Here genius, because you are clearly an idiot.
Chemotrophs get energy by ingesting electron donating chemical substances, which gives them the energy they need for respiration.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Heterotrophs consume other organisms to gain their energy for respiration.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Autotrophs are able to absorb inert substances, and combine them with some form of radiant or abmient energy, and turn them into lower entropy food supplies that they use to power respiration.
https://en.wikipedia.org/wiki/... [wikipedia.org]
So, again-- the answers are:
1) chemicals
2) each other
3) light
Re: (Score:2)
They eat chemicals, light and each other? And you are calling ACs idiots? How do you eat light?
Holy motherfucker, have you ever heard about photosynthesis, or chemotrophs?
Re: (Score:2)
carbon rich amino acids, ammonia, water, methane, and a whole panoply of the building blocks of life all form abiotically in interstellar dust clouds, such as what this star will form from.
Because there is no fusion inside the star, there is not nearly as much energy to rip these complex molecules apart with, and instead they will form complex interplay and layering inside the star, moving around because of convection.
Sinkers, floaters, oh my (Score:2)
This sounds like it would make an absolutely amazing VR world that you could cruise around in. Even more fun would be designing such a world!
Re: (Score:2)
keep telling yourself that AC. maybe if you repeat it enough times it will come true! (No, really, it wont.)
Well there would be a lot of it (Score:3)
And if it developed space travel I wonder if it would notice our kind. Would it even interact as well as the aliens in Blindsight [wikipedia.org]?
Re: (Score:2)
Would it even interact as well as the aliens in Blindsight?
Stretching the definition of "well" there, aren't you ? :-(
Re: (Score:2)
Yeah "to same the degree as the Aliens in Blindsight" .
Great book.
Re: (Score:2)
One of the best! (Maybe spoilerish!)
Explores the relevance of consciousness to intelligence and highlights the possibility that alien life is so different from us that our mere attempts at communication could be considered an assault.
If you haven't read his other works I suggest the Starfish/Rifters series in it's entirety. Almost all of his works are free on his website www.rifters.com by the way.
Re: (Score:2)
That's a pretty big "if". The escape velocity of a star, even a brown dwarf, is pretty high, and if you though that the Earth's atmosphere got in the way of space flight, whew! They'd need to go directly to nuclear rocket.
Then there's the question of how large the minimum intelligent entity would be. They need to be diffuse enough to float. Whoops, that means that their brain "cells" need to communicate with each other via wireless transmission. And that implies at each entity would need a huge transmi
Re: (Score:2)
Fair arguments but I think you are assuming that their means of getting around will be too much like ours. Forget space ships. Consider a plume of information laded bacteria squirted up out of the atmosphere into the path of an orbiting asteroid. They splat on to the surface, some survive and grow into a new spacegoing species.
Re: (Score:2)
Chemical reactions slow down remarkably as the temperature drops. I could envision using this as a spore transportation system, but they'd need to pick an asteroid that was either headed out-system (towards another brown dwarf) or headed towards a plausible planet. And the success rate should be expected to be less than that of wind-pollened plants. If they land on a planet they'll be evolving in the kind of environment we know about subject to things like gravity, so they'll probably need to start in an
Larry Niven Called it (Score:1)
Science really should read science fiction.
Re: (Score:2)
I was thinking more Peter Watts. When did Niven suggest this idea?
Re: (Score:1)
slightly different concept, here it's a failed planetary disk, so a failed solar system, but similar.
Re: (Score:2)
"We know A LOT about clouds. If you've got any cloud questions, ask us."
Carl Sagan's Cosmos on possible Jupiter life (Score:2)
https://www.youtube.com/watch?... [youtube.com]
Sinkers? Floaters? (Score:1)
But then again ... (Score:2)
... it might not.
Heard this before. (Score:2)
The Integral Trees/The Smoke Ring, Larry Niven.
Re: (Score:2)
It's an interesting exercise in working out an environment, but TBH, far from my favourite bit of Niven. I can barely remember the plot(s), nor even if I've actually read more than a couple of the books.
Wait (Score:2)
Wait a minute. Maybe alien live could BE the clouds of a failed star. Think about it!
Re: (Score:2)
Hollywood context (Score:2)
>> Alien Life Could Thrive In the Clouds of Failed Stars
Yeah I think they're called Scientologists.
Oceans have life at different layers (Score:2)
Oceans have life at different layers, so why not gaseous atmospheres of varying densities?
Unless there is something magical about life, its seeds are embedded in the fabric of the universe. Earth coalesced out of a dust cloud and without any human intervention, life appeared and evolved to what we have today. This is a natural process. That it could occur in circumstances other than earthlike does not strike me as farfetched. OTOH, we still can't spontaneously make life in the lab so we don't know all its
Re: (Score:2)
Except for very temporary, small-scale local "inversions", the density of atmospheres increases as you descend into them. Same physics from 100-odd Kelvin (Jupiter cloud tops) to many thousands of K (O-stars).
FTFY
We don't know what we
No life, cannot evolve there (Score:2)
No phosphorous, it's as absolutely essential to any form of life as we know it as carbon is for more than one reason. It's a dealbreaker not to have it. No phosphorous, no life. And no there is not replacement for it, the hoopla over supposed replacement of it with arsenic in a certain bacteria has proven to be false. Replace phosphorus with arsenic and you get dead organism.
Re: (Score:2)
Larry Niven... (Score:2)
The Integral Trees/Smoke Ring books explore a similar idea, though it is based around a gas torus surrounding a neutron star. Definitely a fun read as Niven incorporates the physics of such a system in his world building. He did the math and thought through the model exceptionally well.
Gravity would crush life there (Score:1)