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Saturn's moon Titan could harbor life, but only a tiny amount
- Qem 2y agoAre bolide impact events the only possible mechanism for communication between ice crust and subsurface ocean? Is there no analogue to tectonism on Titan ice crust, to subduct nutrient rich ice?
- indoordin0saur 2y agoYeah the study seems to make 4 assumptions: 1.) The life's only metabolic source of energy is glycine 2.) The life is analogous to glycine metabolizing organisms on Earth 3.) The only source of glycine getting deep into the ocean is through these rare impact events 4.) The life can only survive in the deep subsurface ocean
- datameta 2y agoSpeaking of ocean, water is mentioned several times in discussing Titan but the hydrologic cycle analogue consists of various hydrocarbons. But to the fourth point, I wonder to what extent radiation is a factor in mutation of biological material. It turns out Titan has a rather low surface irradiation coefficient due to being rather distant from Saturn's radiation belt, a weak induced magnetosphere (rare for moons!), and the ions are mostly water-based coming from Enceladus while Jupiter's radiation belts are largely sulphur ions coming from Io.
- indoordin0saur 2y agoThe hydrocarbon oceans are on the surface, but there are liquid water oceans beneath the surface.
- datameta 2y agoIf I'm not mistaken, they are water-ammonia mixture down to -97C, so it would a boon for our understanding of life had it evolved in such conditions.
- nkrisc 2y ago> "Our new study shows that this supply may only be sufficient to sustain a very small population of microbes weighing a total of only a few kilograms at most – equivalent to the mass of a small dog," Affholder said. "Such a tiny biosphere would average less than one cell per liter of water over Titan's entire vast ocean." Assuming for a moment that some life does exist in the subsurface ocean, I imagine it would be most likely that you would then expect to find very, very rare, but highly concentrated pockets of life? Unfortunately I couldn't read the linked study because I was stuck in an endless CAPTCHA loop of trying to find an image of a refrigerator among a varying set of only helicopters, ships, and avocados. I feel absurd just writing that.
- pavel_lishin 2y agoThere's only one refrigerator per liter of images in the CAPTCHA.
- marcosdumay 2y agoAnd unfortunately, the GP's monitor is 2D only, so the total amount of refrigerators was zero.
- 38 2y ago> Unfortunately I couldn't read the linked study because I was stuck in an endless CAPTCHA loop of trying to find an image of a refrigerator among a varying set of only helicopters, ships, and avocados I got through on the first try, and I block third party JavaScript with a whitelist
- zoklet-enjoyer 2y agoAs a treat
- dfedbeef 2y agoA tiny wafer thin layer of life
- deleted 2y ago[deleted]
- bpodgursky 2y ago> The researchers specifically focused on one organic molecule, glycine, the simplest of all known amino acids. This is such a goofy assumption. That any life on Titan would use the exact same amino acids as earth-based life. If you have no clue whether something is possible, sometimes it's better to predict nothing at all.
- Tagbert 2y agoIt’s not goofy. We find these amino acids in meteorites and it is clear that they are widespread in space. Glycine being the simplest is probably the most common and most likely to be incorporated by life. It is a good proxy for an estimate.
- bilekas 2y ago> This is such a goofy assumption. That any life on Titan would use the exact same amino acids as earth-based life. I might be wrong, but I think they use this assumption because they KNOW life has already formed this way, it would be goofy to assume methods that we haven't witnessed right ?
- ceejayoz 2y agoThat's still a bit goofy; it's essentially the same thing as the https://en.wikipedia.org/wiki/Cargo_cult https://en.wikipedia.org/wiki/Cargo_cult phenomenon.
- bilekas 2y agoMaybe I missed the mark here but is it not similar to saying "it seems goofy to look on planets with water just because that's what life required on earth"? I'm not in any way educated on these things but are these not basic building blocks kind of things?
- ceejayoz 2y agoWe know the basic building blocks for Earth life. We currently have zero evidence for any life off the planet, water/carbon-based or otherwise. It would likely be a mistake to assume that we're the only possible setup. Maybe life spreads primarily and very slowly in Oort clouds, and we're a bit of an abberation. Even here on Earth, we've been surprised to find life in boiling water and miles underground.
- causality0 2y agoGod what a fucking leap from the actual results of the study to that article title. The only thing the study indicated with even the barest hint of significance is that there is probably only a very limited amount of glycine being transported from the surface to the interior ocean. That's it.
- NoTeslaThrow 2y agoImagine what humanity could be capable of if we had the grace to ignore the title.
- mytailorisrich 2y agoI think the most plausible takeaway is that, assuming this study is "correct", if a process would only allow a few kg of life at planetary scale then that process is not what life would rely on in that environment.
- julik 2y agoI hope there will be sirens... https://en.wikipedia.org/wiki/The_Sirens_of_Titan https://en.wikipedia.org/wiki/The_Sirens_of_Titan
- SamBam 2y agoI'm interested that their conclusion -- that Saturn could only support tiny life forms such as bacteria -- is not dependent in any way on the distance from Titan to the Sun. Am I wrong in thinking that any life must require a steady input of energy, and that this must come from either solar energy or geothermal energy? Quick Googling says that Titan's core isn't known for sure, but probably isn't very hot. If Titan's life were dependent of solar energy, wouldn't it's distance from the Sun imply very little energy to go around, and so very unlikely to have large organisms?
- delecti 2y agoThe gas giants' moons are heated quite a bit by tidal friction. They're warmer than would be expected just based on their distance from the sun.
- adrian_b 2y agoSolar energy can be captured only by living beings that have reached a relatively high complexity after a long evolution. In places with so little solar energy, living beings might never develop means for capturing it. For the appearance of life, a source of internal heat for the planet or satellite is a necessary condition. As another poster has mentioned, in the big satellites of the giant planets such a source of internal heat exists, because of the tidal forces which cause internal friction. For the internal heat to be able to provide energy for life forms, there must exist some kind of volcanism that cycles matter between the interior and the exterior of the satellite or planet, so that substances that were in chemical equilibrium at higher temperatures are brought to lower temperatures, where they are no longer in chemical equilibrium, which can provide the energy for the synthesis of complex organic molecules. (On Earth, the principal source of energy for the bacteria that do not depend on solar energy has its origin in the iron(II) ions from the mantle and lower crust of the Earth, which are brought by volcanism at the surface, where they are no longer in chemical equilibrium with water, so they are oxidized by water to Fe(III) ions, i.e. rust, liberating elemental hydrogen from the water, which can be consumed by bacteria and combined with carbon dioxide into organic substances, without needing any other source of energy. When rocks are recycled by subduction into the mantle, because of the high temperatures the iron ions are reduced again to Fe(II) ions, completing the cycle by consuming a certain amount of internal heat.)
- bagels 2y agoHow do they know that there wasn't already abundant amino acids in the ocean before accounting for current transfer?