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Space Earth

Brown Dwarf Atmospheres As The Potentially Most Detectable And Abundant Sites For Life 79

Posted by BeauHD from the alternative-astronomical-habitable-zone dept.
RockDoctor writes: Yet another provocative paper emerges onto Arxiv from Harvard's Lingam and Loeb. Today they estimate the volume of space occupied by habitable zones (regions where liquid water is stable) in brown dwarf not-quite stars. They find that it could be orders of magnitude greater than the volume in the atmospheres of Earth-size planets. Brown dwarfs are masses of gas which are too small to sustain nuclear fusion (so, they're not stars), but can have a brief period of fusion of deuterium or lithium shortly after formation (so they're not planets; the boundary size is under debate). After this burst of energy, they slowly cool, for billions of years. This leads to a large volume of the star's outer body -- or atmosphere -- with potentially attractive temperature and pressure. If the brown dwarf is orbiting with a larger star, there may be enough light to allow photosynthesis. Supply of chemicals is uncertain, but not impossible.

While this paper is speculative, the prospects for detecting such life by spectroscopy are plausible with observational instruments being designed at the moment. Previous work on abiogenesis and the origin(s) of life has speculated that life could persist in the atmospheres of Venus and Jupiter, using comparable pressure-temperature arguments. In this respect, the proposal is more conventional.
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Brown Dwarf Atmospheres As The Potentially Most Detectable And Abundant Sites For Life More

Brown Dwarf Atmospheres As The Potentially Most Detectable And Abundant Sites For Life

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  • Wicked Cool (Score:5, Insightful)

    by pz ( 113803 ) on Thursday May 30, 2019 @05:13AM (#58677956) Journal

    THIS is the sort of thing that I read Slashdot to learn about. Interesting, if provocative, speculation based on scientific reasoning. Places to look for signatures of extra-terrestrial life.

    I mean, just reading the summary, I learned that there are parts of the atmospheres of Venus and Jupiter that could potentially harbor life. Cool! That means we could and should be looking within our solar system and have a non-zero chance of the other planets being sterile; we kind of suspected that about places like Titan and Europa, but elsewhere, too? Amazing. I'll click on the links and Slashdot will make money. Tell me more!

    The immediately previous article was about plastic pollution. Why is it here? Apparently because of the tenuous connection to News for Nerds since it reports an effect due to usage by the general public of apps on their phones to order their food. Really? Stories about trash? Stop, please.

    • I agree this is an interesting story! Conversely, I'm not sure why you'd have so much interest in other (potential) biomes but not in our own. Ruining the biome of Earth is as much a staple of science fiction as exploring other worlds is.
      • So they're telling us that we don't need a neutron star to have a smoke ring [wikipedia.org] biome?
        • While I'm generally a fan of Larry Niven's work, I never really took to the "Integral Trees" universe. It's got some interesting science behind the fiction, and very relevant to these ideas. If I'd still got my copies of the books, I'd check to see if Larry took ideas from "atmospheric life" in developing the Integral trees.

          I'm pretty sure at various times in his meta-writing Larry mentioned reading Clarke's (?) "A Meeting with Medusa," which also plays around with atmosphere-dwelling life on Jupiter.

    • I agree with you, but the plastic story got more comments.

    • Re: "THIS is the sort of thing that I read Slashdot to learn about. Interesting, if provocative, speculation based on scientific reasoning. Places to look for signatures of extra-terrestrial life."

      Other stars, other worlds, other life? [holoscience.com]

      December 15th, 1999, Wal Thornhill

      In the last few years a new class of faint stars has been discovered. They are called L-Type Brown Dwarfs because the element lithium appears in their spectra. They are the most numerous stellar objects in the galaxy and bridge the gap b

      • Spectral lines of materials like titanium dioxide, water and other molecular species have been reported from low temperature stars for some time - when I had a personal subscription to Science and Nature in the late 90s, I recall seeing reports as "news" in dead-tree form. That much is hard science, The interesting bit of this work is that estimating the abundances of brown dwarfs (which is increasingly well constrained by observation) and working out the relevant volumes of atmosphere makes them potentiall

        • You might not be understanding just how integrated into the Electric Universe this concept is; although it is possible to focus exclusively upon the science they raise, what Wal Thornhill, Dave Talbott and especially Dwardu Cardona have argued is that this is actually what happened to Earth - that the Earth has a complicated history as a wandering planet which began within the illuminated envelope of a brown dwarf star. They then proceed to re-interpret the many confusing aspects of the mythological record

          • You might not be understanding just how integrated into the Electric Universe this concept is;

            I'm a geologist, which is a subset of scientist. I've met the Electric Universe before. I should have printed it's materials onto soft, flushable paper so I could get some use out of it.

            • Re: "I'm a geologist, which is a subset of scientist. I've met the Electric Universe before. I should have printed it's materials onto soft, flushable paper so I could get some use out of it."

              Perhaps people can judge for themselves the extent to which you are keeping up with the changes happening right now within your own domain.

              Electric Currents in Outer Space Run the Show [eos.org]

              Editors’ Vox
              Perspectives on Earth and space science: A blog from AGU’s journal editors

              A new book explores our understa

    • OP here.

      Thanks for the comments. Sometimes it can be pretty draining trying to put this sort of news out - there's a lot of negativity on Slashdot. But that has really cheered me up.

      Tell me more!

      I'll work through the rest of the comments just now, but I posted a few more thoughts [blogspot.com] on this, after submitting the summary.

  • This is the thingie that astrominor folks should be looking at:

    Brown Note [wikipedia.org]

  • Motivates more study of solar system Jovians (Score:5, Interesting)

    by joe_frisch ( 1366229 ) on Thursday May 30, 2019 @05:56AM (#58678068)

    This paper seems to also indicate that investigating solar system Jovian planets (and Titan and Venus) for life would be very interesting. Even if nothing is found, understanding the atmospheric chemistry better might help with understanding of measurements on brown dwarfs.

    A Galileo type atmospheric probe optimized to look for and analyze droplets might be really interesting. Gaseous atmospheres may be as good or better a place to look for life as is Mars.

    We could send probes to all of the above for the cost of one aircraft carrier, or 1/50 of the F35 program... (or a few Apple headquarters)

    • Re: (Score:2)

      by dryeo ( 100693 )

      Venus would also be an ideal target for a manned mission. There were plans to do a fly-by with Apollo era spacecraft and Earth atmosphere is a lifting gas on Venus so a blimp could float at the height where the pressure and temperature are habitable.

      • It's a chapter in the book I'm trying to write - and haven't put a word to for 6 months. I really should get back to that.

    • We could send probes to all of the above for the cost of ... or a few Apple headquarters

      Can we send the actual Apple headquarters itself? I hear it looks like a giant spacecraft anyway, so shouldn't be hard to retrofit. MacWorld [macworld.co.uk]

    • A Galileo type atmospheric probe optimized to look for and analyze droplets might be really interesting.

      People have been throwing ideas for a "balloon-mobile" explorer for Titan at the drawing board since before the Huygens probe soft-landed. I'm sure that meeting rooms at JPL, JAXA, ISRO, ESA and ROCKOCMOC will be getting new drawing boards to estimate technologies, costs and science programmes ... well, pretty soon.

      OTOH, I remember hearing Alan Stern trying to drum up support for what became New Horizons

  • The light source seems not too important... (Score:5, Insightful)

    by Sique ( 173459 ) on Thursday May 30, 2019 @06:13AM (#58678112) Homepage
    Considering that Life on Earth probably developed in the oceans, and the first lifeforms probably fed on oxidizing for instance S2+ to S3+ or Fe2+ to Fe3+, a nearby bright star seems not too important to have Life spring up. Photosynthesis was a very late addendum to Life, and developed about two billion years ago, thus about one and a half to two billion years after the first lifeforms.

    What seems to be necessary is a stable, water rich environment with carbon and many different ions, and at least one steady energy source.

    • What seems to be necessary is a stable, water rich environment with carbon and many different ions, and at least one steady energy source.

      There's a significant school of thought within the "origin(s) of life" community that looks at pre-biotic chemistry being powered by geothermal energy (in hydrothermal - warm to hot water - systems). Perfectly respectable science - people get PhDs for studying aspects of this. There's an advert for a related PhD studentship on my desktop at this moment.

      Adding photosynth

  • Homogeneity (Score:5, Insightful)

    by necro81 ( 917438 ) on Thursday May 30, 2019 @07:20AM (#58678322) Journal
    One of the things that makes Earth such a great place for life is its dynamism. There is such a wide range of climates and habitats. There are seasons. There is vulcanism. There are interfaces among air, water, land, and ice that allow mixing and surfaces for reactions to occur.

    By contrast, a brown dwarf is likely to be relatively homogeneous. Like Jupiter, there is probably large-scale convection and "storms", but it's all happening in a more-or-less uniform atmosphere - no solid surfaces, no boundaries between disparate materials, no varied phases.

    This does not by any means refute their hypothesis, but it does make me wonder: if everything is more or less the same, where is the spark that allows life to start and flourish? Where are the evolutionary pressures that force life to adapt and change?

    • Re: (Score:3)

      by lgw ( 121541 )

      The thing about Jupiter is: it's big. Interfaces between different temperatures and chemical mixes in convection zones may be a tiny percentage of its volume, and still be many times the surface area of the Earth. Juptier's atmosphere is also complex, as all convection flows are chaotic. It's certainly not a homogeneous ball of gas.

      A brown dwarf with fusion in its core (probably necessary for a desirable temperature) would have a more complex and chaotic atmosphere. Early life on Earth depended on Iron

    • These places may be suitable for boring old microbial life, but that is still life. The complexity of Earth allows for the developed of more complex multi-cellular and, eventually, intelligent life capable of speculating where else life might exist.

    • but it's all happening in a more-or-less uniform atmosphere - no solid surfaces, no boundaries between disparate materials, no varied phases.

      Someone upthread posted a ... scenario of a brown dwarf ingesting and (slowly) digesting a rocky world. That particular scenario is new to me, but stars "eating" planets, asteroids and comets is old news - it's one of the leading scenarios for explaining "Tabby's Star", and there are plenty of less contentious examples.

      I'm going to give that scenario a bit more thoug

  • ... as how intelligent that life is.

    I would consider it a foregone conclusion that life is positively abundant in the universe. The ingredients necessary for it are simply far too abundant for there to be another option.

    What I am considerably less certain of, however, is at this moment we are asking is anybody else out there, if there is someone else doing the same. While the ingredients for life are provably the most common in the universe, since we do not fully understand what the ingredients for

    • Isn't that last an Arthur C. Clarke -ism ?

      To be honest, I'm not really concerned about there not being anyone else in this galaxy. If there are two simultaneous species in this galaxy then most significant size galaxies and most of the luminous matter in the universe is reasonably close to a living ecosystem.

      What worries me is - what is the "Great Filter"? I'm becoming increasingly convinced that the filter is environmental suicide.

      • Re: (Score:2)

        by mark-t ( 151149 )
        It's possible... although I wasn't attempting to quote anyone, I can easily imagine that I'm not the first to say it.

        The "Great Filter", I think, may simply be the staggering improbability that it would happen at all.

        I mean, if advanced life had only a one in 10 to the hundred thousandth power of ever appearing on a world for example, it would be damn near miraculous that it exists at all.

        We can't actually make assumptions about the chance of advanced life elsewhere, because our existence only testifi

  • Brown Dwarfs are essentially gas giants 13x Jupiter masses or larger.
    While their analysis is interesting, it's pretty narrowly focused on temperatures and the possibility of liquid water. That is a large, large step from 'where we might find life'.

    This leaves a TON of questions: the obvious one being a lack of actual surface.

    They mention gravity only once in the paper; at the very top of the cloud layer, Jupiter's gravity is 2.4x earths; a brown dwarf would be substantially higher.

    As far as I could see in

    • Magnetic fields aren't much of a problem for life on Earth, otherwise natural concentrations of magnetic minerals would be desert wastelands (before the mining operations made them so). Which they're not.

      UV and nitrogen oxides produced by lightening are mutagens - which life evolves to manage the resultant copying error rate. There is considerable redundancy built into the genetic system of life on Earth (most amino acids have two possible encodings in the genetic code, for example) which is probably a rel

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