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Need help with a planet...and other questions!

  1. Oct 13, 2015 #1
    Hi!
    So...as you can see from the title,I'm having a problem with an alien planet in a story I'm creating,but not one you'd think would be:
    The planet harbours boron-nitrogen-based life with ammonia as a solvent.The only problem in this is:
    Boron is scarce.So,I need help in terms of making up a plausible reason for boron to exist in large quantities on that planet.I read somewhere(can't remember where) that "this problem can be largely solved by star systems with increased levels of cosmic ray spallation." Can someone explain what does this exactly mean? Yes,I have searched it up,and,unfortunately,since English isn't my first language,Wikipedia wasn't kind to me with all of its complex terms! So,any help would be greatly appreciated!

    Oh -- and,that being said -- it would be of great help if you could give me your opinion on two questions I'd like to ask you!

    -The planet being cold(for obvious reasons) and dark(but not entirely dark) -- how do you think that would influence the senses of the living beings on the planet? I'm also planning the planet to have one intelligent alien civilization,so how do you think the environment would influence them too?

    -Which element do you think would be most plausible as an alternative to oxygen on the planet?

    That's all,thanks guys.
     
  2. jcsd
  3. Oct 13, 2015 #2

    mfb

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    High-energetic cosmic rays can split up nuclei and produce boron out of heavier elements.
    In the solar system, there are about 30000 atoms of carbon for every atom of boron. And we have cosmic rays as well. I don't see how this works out.

    Even on Pluto (where ammonia freezes), the days are significantly brighter than an Earth night with a full moon. Eyes are useful on the surface as long as the atmosphere is not completely blocking light.
    I don't know your BN-based life.
     
  4. Oct 13, 2015 #3

    JBA

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    I am not an astronomer or physicist but the below is what I have found and what might be the possible source of the Boron you need for your planet.

    spallation
    A type of nuclear fission reaction in which cosmic rays of light cause a nucleus to emit a large number of nucleons (protons and neutrons), leading to the formation of new elements (nucleosynthesis).

    nucleosynthesis
    The formation of heavier elements from lighter elements by nuclear fusion in stars.

    From other sources I found:
    1. Basically, at this time Boron can only be created inside the supernova of a star.
    2. The small amount of Boron on our planet was formed during the very early stages of the creation of our universe.

    From this information, I might suggest that there may be two reasons why your planet could possess a large amount of Boron:

    1. Your planet was formed during the early formation of our universe when there was much more free Boron to be gathered during the planets formation.

    2. It was near enough to a supernova to have been bombarded with a large number of boron modules ejected from the supernova while the planet was forming around another star.

    In either case, there should also be a large number of other heavy radioactive elements from the supernova on the planet as well; and, that might also lend to your story.
    For example,: Only a civilization of creatures composed of stable heavy elements should be able to survive on a planet with a very high level radioactivity level from the those radioactive elements.

    I hope this give you some help with your problem.
     
  5. Oct 13, 2015 #4

    mfb

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    The fraction of heavier elements increases over time. The big bang didn't produce boron, you need stars producing carbon, ejecting this, and then cosmic rays making boron out of it. That process needs time.
    Why? Radioactivity can be dangerous to life on Earth because it breaks chemical bonds. Those chemical bonds are (in general) stronger for lighter elements.
     
  6. Oct 13, 2015 #5

    JBA

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    I stand corrected regarding my comment regarding the creature survival issue, I expanded a biological survival beyond its application without realizing it.

    With regard to my comment regarding the early formation please see the multiple statements in the below Wikipedia reference, although you may consider an unreliable source.

    https://en.wikipedia.org/wiki/Cosmic_ray_spallation
     
  7. Oct 13, 2015 #6
    Thanks for the answers,guys!

    So,to make a consensus regarding a reason for boron to be abundant on a planet,the first reason you mentioned can or cannot be considered as plausible(for use in fiction,atleast)?
    Also just to note: I'll actually need two planets based on the same biochemistry(boron-nitrogen,ammonia) that will be very distanced between themselves(with,for example,Planet 1 being far closer to Earth,than Planet 2).
     
  8. Oct 13, 2015 #7

    DaveC426913

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    What do you mean by alternative? Do you mean a respiration requirement? An erstwhile oxidizer?

    What makes you assume it needs either? You'd have to figure out what the BN cycle needs as fuel source.
     
  9. Oct 13, 2015 #8
    "What do you mean by alternative? Do you mean a respiration requirement? An erstwhile oxidizer?"

    By alternative,I meant a respiration requirement.

    "You'd have to figure out what the BN cycle needs as fuel source."

    That would be the case if I:
    1.Had a good scientific knowledge(I don't.)
    2.Was more focused on the science,instead of the story.Note that what I'm trying to do here is to just inject that bit of plausability into the story,without having to do heavy research.
     
  10. Oct 13, 2015 #9

    JBA

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    At this point, I have seen several references that indicate that indicate that No. 1 and No. 2 are reasonable scenario for a high boron level at least for the purposes of science fiction. For example, the below indicates a large amount of Boron in interstellar gas and dust. At the same time, I cannot claim any personal level of knowledge on this subject, everything I am presenting is strictly what I have been able to find on Internet reference sites.

    A star gains heavier elements by combining its lighter nuclei, hydrogen, deuterium, beryllium, lithium, and boron, which were found in the initial composition of the interstellar medium and hence the star. Interstellar gas therefore contains declining abundances of these light elements, which are present only by virtue of their nucleosynthesis during the Big Bang. Larger quantities of these lighter elements in the present universe are therefore thought to have been restored through billions of years of cosmic ray (mostly high-energy proton) mediated breakup of heavier elements in interstellar gas and dust. The fragments of these cosmic-ray collisions include the light elements Li, Be and B.
     
  11. Oct 13, 2015 #10

    mfb

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    Nothing there states that the production rate or even the accumulated amount would reduce over time. More boron is produced than destroyed, so the amount of boron is constantly increasing (but so is the amount of other elements other than hydrogen).
     
  12. Oct 13, 2015 #11

    JBA

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    OK, that makes sense.

    On that basis it would seem to follow that, contrary to my statement about the early formation of the planet, in fact, the later the planet's creation the more boron would be present on the planet; because over time a greater accumulation of boron would accumulate in the interstellar dust and gases from the combination of the early creation plus any intervening supernovas in the vicinity of the plant before its creation.
     
  13. Oct 13, 2015 #12
    "...in fact, the later the planet's creation the more boron would be present on the planet"
    Then,since my story is set in the present,the question,I guess,would be:Was boron abundant enough in the universe some few billions of years ago to create a planet?
    I think the answer may not...well,make me happy haha.
     
  14. Oct 13, 2015 #13

    JBA

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    I think the low level of boron on our own planet earth answers that question for you.
     
  15. Oct 13, 2015 #14
    Yep.Pretty much.So,well...I guess,the conclusion is that there is absolutely NO plausible reasons for a significant amount of boron to exist on a planet...
    When we're talking about alternative biochemistries though,what do you think about nitrogen-phosphorus-based one instead?
     
  16. Oct 13, 2015 #15

    JBA

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    I am not going to be any help on this issue. My specialties definitely do not include any elements of chemistry or potential inorganic life forms!
     
  17. Oct 14, 2015 #16
    Haha,okay! Nonetheless,thanks for trying to help.
     
  18. Oct 16, 2015 #17
    Have you checked wiki:
    https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry#Ammonia

    ?

    Are you creating a planet or a moon? Moons are trendy in this seasons ;) and in this case a moon orbiting a gas giant would be ultra plausible.

    However, if you are following your variant I'd add two important things:
    -heavy radioactive elements tend to decay during billions of years
    -heavy elements (especially if planet become melted because of some... nuclear decay ;) ) tend to drown to the core of planet
    (damn it... I would not be afraid radiation... just evaporating billions year earlier because of thermal heating of some volatiles like... ammonia would seem for me a more inconvenient part)

    So the result that I would see, would be in such case rather stratified planet, with unusually high density in comparison to nearby ice balls.
     
  19. Oct 16, 2015 #18
    "Have you checked wiki:
    https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry#Ammonia ? "
    Yep,I have checked it.What I am,though,struggling to think of,is how most of what is said on it would affect the actual life forms.

    "Are you creating a planet or a moon? Moons are trendy in this seasons ;) and in this case a moon orbiting a gas giant would be ultra plausible."
    I want it to be a planet,actually,but a moon is no problem either!

    And...last,but not least,I don't know if I really have a choice,but I dont really wanna mess with the radioactivity stuff -- it just adds more and more complications that I would need to research etc.

    So,to say it again:I'm aiming for a planet,which is based on an alternative biochemistry(preferably boron,and DEFINITELY not silicon).
     
  20. Oct 16, 2015 #19
    Ideas:
    1) Very slow metabolism? That would affect reaction time.

    2) Easy flight, if your planet resembles Titan: https://en.wikipedia.org/wiki/Titan_(moon)

    3) Very little light for photosynthesis or analogous process (roughly counting, judging from Saturn distance 1/81 or 1/100) Expect desperate fight for light and poor environment that is not able to feed many animals per square kilometre.

    4) Ammonia is good solvent of many salts, no idea how that would affect the environment. Just possibly you can get some salty ammonia and fresh ammonia, no idea what your organism would like.

    5) Still thinking how to get this boron...
     
  21. Oct 17, 2015 #20
    That would,unfortunately,pretty much undo the story I want to create! Instead of the very slow metabolism,I think a slower evolution process would do the job.

    I think making the autotroph organisms dark would solve atleast a bit of that problem,no? And with the biochemistry being totally different,could there be ways around this problem? I really don't know what I am talking about,just asking if the biochemistry being different could affect/solve much of the problem.

    And...I actually have an idea around this,but it's some really really really(multiply "really" by how much times you wish) fictionalized one.

    It involves an ancient alien civilization(one which will have its role in some big parts of the story) heavily influencing the planet's biochemistry while the planet is still young.Not plausible?Nope?Not a tiny bit? Yep,thought so.
     
  22. Oct 17, 2015 #21
    You know the rule of thumb that reaction speed slows down by factor of 2-3, with each ten Celsius degrees less?
    https://en.wikipedia.org/wiki/Q10_(temperature_coefficient)

    Slower evolution? So your planet is ex. 8 bln years old? Then make the star small, as big stars tend to cause problems related to luminosity change during its lifetime.

    Your idea is to:
    a) really make an original and more or less realistic ammonia / boron based life?
    b) place Earth like life to such planet and purely for flavour purposes claim that it uses alternative biochemistry?

    No, it's not an aggressive question, but more a question what are your needs.

    I heard this idea of black plants, but I personally consider this idea as too lucky to be true. On Earth quite a few different strategies were used, some underwater plants really needed light sensitive substance and failed evolving that. (disclaimer: my private opinion and not law of nature)

    Suggestion: what about just trying to follow weird implications from such planet? I thought that's where the fun start... So for example you end up with small, low gravity planet, where trees grow for millennia to reach hundreds of meter and put its competitors in shadow?



    Deus (Alien?) ex machina? Maybe before resorting to that let's think first about some lucky list of events that lead to desired result.

    I'd think more about one thing - on Earth cyanobacteria caused havoc by producing all that oxygen. Maybe you'd think about similar event on your planet?

    Additional issue - have you thought about your planet temperature / composition? Like dunno crust made of water ice, on top of which all this ammonia is flowing?
     
  23. Oct 18, 2015 #22
    It's not an aggressive question,in fact I'm rather glad that you asked,otherwise I don't really know if I would have brought it up! My needs are these:
    -- Yes,I need an original and intelligent ammonia/boron-based life.And I need decent reasons for it to happen! And,since boron is actually scarce in the universe,I was hoping such planet would be such a rarity that there would be few such planets in the observable universe.(since the plot is also a human helping them find another planet after their home has become non-habitable -- and well,I'm kind of worried about revealing too much,so I guess that's enough revealing...or?)

    That's actually a nice idea,and,though,as I said above,it'd have to add up to a planet that harbours intelligent life.Though,wouldn't that cause a problem -- since we know that ammonia has a melting point of -78 C and a boiling point of -33 C,so if the planet was to be a low-gravity one,wouldn't that make its temperature span of liquid state even smaller,like,too small for a stable environment?

    Yeah,that's also a very nice idea! So,you're implying that there could be,a similar organism on the planet that could produce big amounts of boron and literally change the planet.Well,all good,I guess...haha.No,but,in all seriousness,I don't know...do you think such event would be really plausible?

    The planet temperature -- yep,I've thought of it.I actually thought of the planet to be a bigger one than Earth,around 1.5-2 times bigger,so that would wide up the temperature span of the liquid ammonia than what it is on our planet,right? (I don't know how much to be exact,but it won't really be much,I guess?) Also,liquid ammonia on top of water ice...oxygen in a ammonia environment doesn't seem to me like a good idea...?
     
  24. Oct 18, 2015 #23

    mfb

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    The boiling point of ammonia depends on pressure. Increase pressure and you get a larger range.
     
  25. Oct 18, 2015 #24
    OK. Gottcha.

    I thought about this boron origin:
    -Realistically, it must have been created billions of years earlier, so not much evidence would be left anyway.
    -If it was created by cosmic radiation, then by the same process also plenty of lithium and berilium created. So it means that those 2 elements are much more abundant than usual, and that's mostly the only trace left. Radioactive elements already passed away.

    (If the planet is older than Earth, then it has got less U-235. If it has got more lithium it means, that maybe nuclear fission would be harder to provide, but fusion - easier ;) )

    As MFB said - boost atmospheric pressure. You would get it liquid in bigger temperature range.



    I'm afraid - not specially. But you don't need that anyway.



    Free oxygen may react, water ice - not specially. I would not neglect also carbon dioxide. It would be gaseous or condense on ice caps.

    Dunno about this size. I would think that small light ice ball is funnier, as it allows easier flight and easier space travel.
     
  26. Oct 19, 2015 #25
    Could the boron have been dumped there billions of years ago by a primordial civilization as a waste product? But more specifically, why does boron matter to your story? There are plenty of other atoms that are capable of creating genetic codes, and some are far more abundant than boron.
     
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