I wonder what kind of buglife lives down in the depths.
Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds
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Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds
#72Ceres 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).
I 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?
Well, 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.
Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds
#73Is this actually H2O water? I read the article but I am still unclear. I am often excited to hear that water was discovered on some planet or moon but its always a disappointment to learn that its liquid methane or some other liquid that is not actually H2O water.
What other kind of substance is called 'water'? As far as I know only H2O is described as water.
Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds
#74Earlier quoted context omitted.
I 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?
Numerous other ideas exist for alien life, but most of them have their shortcomings. It all boils down to chemical reactions and physics. Imagine a universe of only helium. No valence electrons would be readily available, so chances are you are not going to see helium molecules. Lithium, sure, as a metal. Continue examining various smaller (and more plentiful elements). Fluorine? Well, only one slot available, so you…
Another problem with silicon is that its basic oxide (Silicon Dioxide) is a solid that is non-reactive with virtually everything.
If you assume water based life, there is almost certainly going to be oxides involved, such as how CO2 is involved with earth life.
And I think water based life chemistry is an extremely good bet, because alternative liquids based off of light, common elements are either only liquid at very low temps, (ammonia, methane) extremely reactive ( Hydrogen fluoride, hydrogen sulfide), or both.
Another consideration with silicon is that the earth contains vastly more silicon than it does carbon (in many ways life on earth is fairly carbon starved), yet life based on carbon arose, not silicon.
Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds
#75Earlier quoted context omitted.
Numerous other ideas exist for alien life, but most of them have their shortcomings. It all boils down to chemical reactions and physics. Imagine a universe of only helium. No valence electrons would be readily available, so chances are you are not going to see helium molecules. Lithium, sure, as a metal. Continue examining various smaller (and more plentiful elements). Fluorine? Well, only one slot available, so you…
This is so non esoteric. I can't remember who said it but I'm reminded of the old saying: "if you can't explain something to a high school student then you don't understand it". You certainly understand it and I certainly appreciate you sharing your understanding in such an accessible way, thanks.
I think it was Feynman: https://kottke.org/17/06/if-you-cant-explain-something-in-si...
Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds
#76Ceres is a good place for a lander and rover then. Might be some action there. Face it, Luna and Mars are boring, low-value real estate.
Upper atmosphere of Venus could be high value, if we just shift the states and view the surface as deep underwater and the clouds as land.
Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds
#77> Dwarf planet, believed to be a barren space rock, has an ‘extensive reservoir’ of brine beneath its surface, images show Believed by who? We already knew it was made substantially of ice. Isn't this just discovering that some of it is liquid? Wikipedia quotes a PDF from 2017 regarding the quantity of ice, and by then the fact of Ceres having so much ice had already been worked into the story line of The Expanse.
Previously it was thought to be mostly frozen and hydrated minerals (mud), without any substantial oceans.
Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds
#78Ceres 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).
I 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?
Everyone 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.
Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds
#79Ceres is a good place for a lander and rover then. Might be some action there. Face it, Luna and Mars are boring, low-value real estate.
Upper atmosphere of Venus could be high value, if we just shift the states and view the surface as deep underwater and the clouds as land.
I thought the atmosphere was mostly carbon dioxide and sulfuric acid. What makes it potentially high value?
Re: Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds
#80Earlier quoted context omitted.
I 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?
Numerous other ideas exist for alien life, but most of them have their shortcomings. It all boils down to chemical reactions and physics. Imagine a universe of only helium. No valence electrons would be readily available, so chances are you are not going to see helium molecules. Lithium, sure, as a metal. Continue examining various smaller (and more plentiful elements). Fluorine? Well, only one slot available, so you…
Thank you for that write up.
What about non-chemical life. What I mean by that is something like a giant CPU with traces literally the size of freight trains? I recently finished the first Dark Tower book and it’s got me thinking about scale.