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Ceres is one of the more interesting candidates for life in our solar system. Ceres is in the habitable zone for our solar system (although just barely), it's s
by gaukes 6y ago
Ceres is one of the more interesting candidates for life in our solar system. Ceres is in the habitable zone for our solar system (although just barely), it's surface temperature is -30 F (eq. to winter in Greenland), and it's detected that the water on the surface is 20% carbon by mass (though that can mean a lot of things).
- api 6y agoThe question is whether there is a source of energy for that subsurface ocean. If it's geologically dead the entire thing could be uniformly quite cold. Unlike some of the moons of Jupiter and Saturn it's not headed by gravitational tidal effects.
- baggy_trough 6y agoIf that's the case why would it be an ocean at all, rather than a block of ice?
- ojnabieoot 6y agoThe article said it was a brine ocean, so salinity or some other solute - even at Earth gravity and air pressure, highly saline water can have a freezing point as low as -20C.
- baggy_trough 6y agoThe maximum surface temperature on Ceres is -118C. How would you get to -20C without geological heating?
- api 6y agoPressure? Water unlike most materials expands when it freezes.
- darkerside 6y agoWhen you apply pressure to ice, does it melt or freeze? Google says, https://van.physics.illinois.edu/qa/listing.php?id=1593 https://van.physics.illinois.edu/qa/listing.php?id=1593
- ojnabieoot 6y agoThe idea of multicellular life on Ceres is implausible for the reasons you mentioned, but there could be something like archaebacteria or other extremophiles with very slow metabolisms and which don't reproduce very often. As it's a brine ocean, the water could be chemically "hot" enough that a form of life is sustainable in a bio-geological cycle. Here's an interesting article exploring the lowest possible temperature for life on earth (which is largely focused on vitrification blocking cellular metabolism but has both theoretical and empirical insights): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3686811/pdf/pone.0066207.pdf https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3686811/pdf/pon...
- op03 6y agoI had to stand around waiting for a bus in 0 F for a few years of my life. Did not detect any life around that bus stop.
- saagarjha 6y agoThis is an excellent microcosm of the problems searchers of extraterrestrial intelligence face.
- 618033988749894 6y agoThat was one late bus.
- nkrisc 6y agoYou didn't look closely enough. You were surrounded by it.
- orthecreedence 6y agoAre you an android?
- bzb4 6y ago0 degrees fahrenheit = -17.778 degrees celsius
- smithza 6y agoWhat of the lack of atmosphere and lack of active mantle/core? Solar energy has little chance of staying within the system.
- bjo590 6y agoIsn't surface temperature a good proxy value of the amount of energy inside the system?
- jayparth 6y agoWell not necessarily. The Martian equator can get as hot as 18C. It doesn't retain the heat (due to no atmosphere) and it gets cold like even a few centimeters off of the surface.
- Symmetry 6y agoThe potential lack of vulcanic and geological activity now is a big problem. For the first 700 millions years life on Earth depended on chemosynthesis and that's where the energy for that comes from. Presumably there could have been more active geology far in the past, though, possibly implying life that died out.
- toshk 6y agoI always wondered why we are overly focused on the conditions that created life on earth. Arguably it makes sense to see similar conditions lead to life. But do we really know enough to assume that's only way?
- freehunter 6y agoBecause it’s hard to detect life on other planets. It’s easier if we know what we’re looking for. We know where we came from, so it’s easier to detect.
- renewiltord 6y agoWell, look at it this way: you left your home in the morning for work, went to lunch, went back to work, met a friend for coffee, dropped by the office to pick up your stuff, then got home and found you didn't have your wallet. You know that, in the past when you lost your wallet, you dropped it somewhere or you left it behind somewhere. However, because you are a free individual and because the universe is full of possibilities (including the event that the quantum froth poofed your wallet away and created an identical one in your hedge), you can do practically anything now in search of your wallet. Do you: * Retrace your steps to see if your wallet is anywhere along the path * Call your mother and see if she has your wallet * Begin a global wallet-hunt in case the wallet was transported to Cuba Like most people you have an intuitive understanding of what to do: Given limited resources you should allocate them in order of decreasing likelihood of success. Most things do not lead to life. Our prior on "There is silicon-potassium self-replication on Charon" is pretty low because our prior on "X self-replication" is pretty low for most things. Try it out. Suggest an alternative and honestly set your priors on it, then condition those priors on the evidence that you have seen on Earth, and the limited evidence from the Moon and Mars. Now look at those posteriors for your alternative and compare it with the kind of life we know. Almost certainly microscopic, but if it isn't, you should publish.
- BurningFrog 6y agoEveryone agrees that (1) as far as we know, life can arise from a zillion different circumstances, and/but (2) the sane thing is to first look for it in environments similar to the only place we know has life.
- loosetypes 6y agoWould evolutionary timelines or cycles be slower in an overall colder planet? (Thinking of those interactive diagrams for temperature on the kinetic energy of molecules zooming around in closed space)
- clarkmoody 6y agoDid you ever read Dragon's Egg? It's a speculative hard sci-fi that posits ultra-fast evolution for life on the surface crust of a neutron star!
- loosetypes 6y agoInteresting! Thanks. No I have not. Although I was previously recommended Rocheworld by a former NASA researcher, with the note that Robert L. Forward made every effort to describe a scientifically plausible double planet. Incidentally, it looks like Dragon’s Egg is his only work available on Audible. I’ll add it to my list.
- raghava 6y ago> Dragon's Egg TIL! Oh, looks like this movie "Evolution" ( https://en.wikipedia.org/wiki/Evolution_(2001_film) https://en.wikipedia.org/wiki/Evolution_(2001_film) ) was also on those lines then!
- rbanffy 6y agoIt's an interesting idea, but I find characters developed on the surface of a neutron star will end up being implausibly flat, lacking any depth. (badum tish)
- clarkmoody 6y agoI see what you did there... Also, the book does describe a character's apprehension at climbing to the dizzying heights of a few millimeters off the surface.
- 6y ago
- walrus01 6y agoConsidering that there's organisms that live at ridiculous pressures, with absolutely no sunlight and at the extreme temperatures of deep sea volcanic vents, I would not be surprised at all. https://en.wikipedia.org/wiki/Hydrothermal_vent https://en.wikipedia.org/wiki/Hydrothermal_vent https://en.wikipedia.org/wiki/Hydrothermal_vent_microbial_communities https://en.wikipedia.org/wiki/Hydrothermal_vent_microbial_co...
- crowbahr 6y agoThe question is can life arise in such an environment, or only migrate to one. That's yet to be determined as far as I know: extremophiles have all evolved from less tolerant life forms as far as I'm aware.
- eru 6y agoThough, of course, you might expect to see that, even if life can arise in extreme environments: It's uncontroversial that life is much denser in more hospitable environments. If the extreme environments are in regular contact with the hospitable environments, and if evolution is sufficiently random, you would expect over time that most organisms anywhere have an ancestor in the hospitable environment. Even if life can arise in the extreme environment.
- bitreality 6y agoWhat is the most hospitable environment? A tide pool? Also the most hospitable environment for genesis is likely different from the most hospitable environment for a complex ecosystem.
- Symmetry 6y agoFor life without photosynthesis, which takes a while to develop, some place with a lot of free chemical energy because the first replicators will be very inefficient. White and black smokers under the sea are usually put forward as candidates.
- 6y ago
- austincheney 6y ago-30F is too cold for Earth life though. Enceladus is known to have substantial warm salt water. https://en.m.wikipedia.org/wiki/Extraterrestrial_liquid_water https://en.m.wikipedia.org/wiki/Extraterrestrial_liquid_wate...
- Tepix 6y ago-30F (-34°C) is the surface temperature. There are probably not many people who believe that Ceres has life on its surface.
- QuadrupleA 6y agoHmm... according to wikipedia Ceres' surface is 110 - 155 Kelvin, or a toasty -262 to -181°F. https://en.m.wikipedia.org/wiki/Ceres_(dwarf_planet) https://en.m.wikipedia.org/wiki/Ceres_(dwarf_planet) Which makes sense, with little to no atmosphere. If that's correct I'm a little surprised this got voted up to top comment.
- MPSimmons 6y agoThe comment you replied to almost definitely relied on the data in the "Geology of Ceres" wikipedia entry[1]. This is from 1991, and was strictly an estimate. The Dawn probe in 2017[2] got a better measurement, of 110K-155K. 1 - https://en.wikipedia.org/wiki/Geology_of_Ceres https://en.wikipedia.org/wiki/Geology_of_Ceres 2 - https://sites.nationalacademies.org/cs/groups/ssbsite/documents/webpage/ssb_183286.pdf https://sites.nationalacademies.org/cs/groups/ssbsite/docume...
- xxs 6y agoI read that -30F, converted to C (5/9 of -62, like -35) and ughh, no way. That "planet" is too far away.
- f_allwein 6y agoin case you’re wondering: That’s between -163,15 and -118,15 °C.
- lopmotr 6y agoYou really shouldn't put that 0.15 on the end. The numbers weren't that accurate to begin with so it gives the false impression that those digits mean something. I hope it doesn't feel like I'm picking on you but I can't help myself saying something because this is a pet peeve of mine. Rounding appropriately is taught in physics class at school but I think most people don't learn that or think it doesn't apply outside of class.
- Sharlin 6y agoNot sure why you were downvoted. The concept of significant digits is pretty important.
- 9nGQluzmnq3M 6y ago> the water on the surface is 20% carbon by mass Sorry, can you explain what you mean by this? Are you using "water" figuratively for all liquid, as opposed to H2O?
- Symmetry 6y agoWe conventionally call the Earth's seas "water" despite the fact that they have a lot of dissolved CO2 and fish in them. Presumably Ceres's seas don't have anything like a fish but without microorganisms to scavenge they'll tend to have a lot of carbon containing compounds.
- thefounder 6y agoSource?