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Cosmic rays are energetic particles coming from space that hit the Earth's atmosphere and produce a lot of secondary radiation (some of which we see in visible light as aurorae). Would it make sense for an organism floating in the upper atmosphere, or even on the brink of space, to try and make this energy work for them, as plants do using the photons from sunlight to split water? Or are cosmic rays too destructive, or too unwieldy, or too sparse for such use? The question is not confined to Earth, of course, or to organisms similar to those living on today's Earth. I'm trying to decide if a microbial biosphere could live off cosmic radiation and its subproducts.

P.S.: This post touches on some of the same points as my question, though I'm thinking more about a rogue planet far from any star-like energy source (i. e. no pulsars or black holes nearby).

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  • $\begingroup$ The overall energy flux of cosmic radiation is minute, while the energy of a single "cosmic rays" is far too big to be useable by any chemical process. $\endgroup$ – Karl Jan 21 '17 at 21:40
  • $\begingroup$ @Karl I guess that must be so, but do you have figures on that? On Wikipedia it says that "cosmic ray energy density averages ~1 eV/cm³" (which is indeed minute), yet it also says that Earth gets ~10⁴ particles of avg 10⁹ GeV per second per square meter (and presumably many more at lower energies). Am I missing something? $\endgroup$ – pablodf76 Jan 21 '17 at 22:03
  • $\begingroup$ Does the organism need to evolve, or can it have been designed in a lab and then put into place? It may not evolve to feed off of cosmic radiation when there's regular sunlight but it's possible that an engineered organism could make use of it $\endgroup$ – Zxyrra Jan 21 '17 at 22:47
  • $\begingroup$ @Zxyrra I'd prefer if it evolved naturally. But in fact I'd consider the possibility of little or no sunlight to begin with (think a rogue planet or something like Planet Nine, way out from the Sun). $\endgroup$ – pablodf76 Jan 21 '17 at 22:55
  • $\begingroup$ At flux of 1 per sq km per year (btw solar energy is around 10 to the power of 20 at least depends on set up) I think ur creature spend their entire life in hibernation... $\endgroup$ – user6760 Jan 22 '17 at 9:49
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I would say that yes, it's borderline possible.

The organism should be very resistant to ionizing radiation; a Universe that allows Deinococcus radiodurans to exist would have little trouble in producing this new critter, even limiting ourselves to DNA.

The organism would of course need to consume ordinary matter to replicate; it would therefore find it way more convenient to (also) extract what energy it can from that matter. Actually it's likely that the capability of absorbing cosmic radiation would evolve from the former; the organism acquires matter and this interacts with cosmic radiation, supplying harvestable energy. Once this kind of matter is more and more incorporated into the new generations of the organism, it will "optimize" itself to directly take advantage of the radiation.

An organism could not begin directly using cosmic radiation, since to do that it would need chemicals and structures that would be already pretty complex. It would need to start from simple chemical reactions, and evolve to first defend against, then make use of the radiation. The most obvious evolution pressure line would be if the defense takes the form of some radiation-hardy chemical, which is transformed on impact generating much higher-energy compounds that would be initially disposed of. Afterwards, any mutation allowing to extract energy from such compounds would have an enormous evolutionary value.

This is not unlike what already happened to radiotrophic fungi, which produce a special kind of melanin that is capable of harvesting energy from gamma radiations. It would be more difficult (!) for our hypothetic organism, in that cosmic rays are much more penetrating and energetic than gamma rays and therefore require proportionally more massive interception.

And, of course, the organism would need to live somewhere with a lot of cosmic rays.

One possibility would be some sort of low-temperature outer space slug capable of accreting a "black ice" carapace. It would migrate to the safe center of cometary nuclei to spawn, then come out when the carapace is thick enough to both defend the young slug and supply it with energy. The slug would need to have a very low metabolic rate, and be based on a totally different organic chemistry than Earth organisms.


There's something along these lines in "Camelot 30K" by physicist Robert L. Forward, where a (macroscopic) lifeform is presented that harvests atomic nuclei transmuted by the impact of cosmic rays on distant comets.

"The initial energy source for the kerac civilization comes from the background cosmic radiation, which creates long-lived excited molecules and free radicals in the ice over long periods of time". He drew an arrow leading to another box that he drew in the rotund shape of an iceworm. "Out on the farms, the iceworms and young heullers tunnel through the untouched ice around the periphery of Camalor. They extract free radicals frozen into the pristine ice and use them as a source of energy to grow and continue tunneling. Those long-lived free radicals are the first level energy source of the kerack food chain, since the iceworms and heullers are harvested as meat. While the iceworms are doing that, they also extract from the dirty ice all the unstable radioisotopes that the dirt and ice contain."

(While different organisms are named - iceworms, heullers, keracks - it is posited in the book that they are actually all alternate phenotypes of a single organism, the kerack hive drone, not unlike what happens with bees).

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Cosmic rays might first affect some non-living substance, which then provides energy and/or nurishment to the life.

That might indeed be a critical factor, like fixing nitrogen for the base of the food chain.

These cosmic rays can cause chemical reactions or nuclear reactions, such as 14C on our planet. So it could be a complex cascade of reactions, bringing energy down into the biosphere.

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  • $\begingroup$ I just had a look at all the reactions cosmic rays create when they hit our atmosphere. Some of them might be useful, but the problem is whether the amounts produced are significant and realistically usable by living organisms. $\endgroup$ – pablodf76 Jan 21 '17 at 22:57
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It can't exist and this is why

This organism would have to be unlike any that lives on Earth. First of all, if the organism was in our upper atmosphere it would be too protected from the cosmic rays for sustainable life. If it has DNA, it would have to be very protected in order to prevent defects and damage. We're talking some kind of biological space suit as it were. All life that we know of has some kind DNA so this is pretty much a given.

Another factor is the distance between organism and producer of the cosmic rays. Obviously the further, the more sparse and unreliable it would be as an energy source, too close and it might get incinerated. Just like Earth, I suggest some kind of Goldilocks Zone where the conditions are 'just right'.

All this being said, I would assume the organism also needs some kind of respiratory system, and a way of excreting unwanted gases, because there isn't any thing that can survive from nothing but charged particles.

To conclude, I do not believe this is possible because the organism needs to be able to absorb harmful cosmic radiation with out being harmed. It also needs to be outside of a planet’s magnetosphere whilst still being able to diffuse with gases.

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  • $\begingroup$ I understand that cosmic rays can be too strong, which is why I also asked about their subproducts (i. e. the secondary particles and radiation that they give off when they collide with the atmosphere). These an organism could use while staying inside the atmosphere. If energy could be extracted from them, an autotroph could use it to split useful molecules and build tissues. I haven't worked out that, since I wanted to check the basic point first. $\endgroup$ – pablodf76 Jan 21 '17 at 20:50
  • $\begingroup$ @pablodf76 But that's nothing new whatsoever. Humans skin absorbs UVB from the sun which produces Vitamin D. Plants use energy from the sun for photosynthesis. You said it yourself, the energy splits water molecules. You're describing Earth ecology. $\endgroup$ – Garto Jan 21 '17 at 21:15
  • $\begingroup$ No, actually I'm describing an alternative to it, using other forms of radiation, that could work either on Earth or on a different planet even if there were no sun nearby. $\endgroup$ – pablodf76 Jan 21 '17 at 21:19
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    $\begingroup$ Using what other forms of radiation? There are no cosmic ray by-products that aren't used by earth life. That would just be a waste. $\endgroup$ – AngelPray Jan 21 '17 at 21:33

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