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I don't know if there are any astrobiologists or chemists, but this brings to mind one of my favorite pet theories regarding abiogenesis, one that I've been thi

I don't know if there are any astrobiologists or chemists, but this brings to mind one of my favorite pet theories regarding abiogenesis, one that I've been thinking of more and more since the new horizons mission. When we did the flyby of Pluto, I was drop jawed when we saw how dynamic the surface was. I sincerely expected a rockier, more oxidized, surface with no clear evidence of a geological cycle. Obviously what we saw was far more complex, and it brought the idea that a geology of volatile ices would be possible on these more marginal bodies (like Pluto). The question I have is regarding what kinds of chemistry are possible on icy bodies like Pluto. If there is a complex geology, this indicates to me that things are going from liquid to solid (nitrogen ice, oxygen ice, etc..), so are some kinds of chemical bonds (specifically, organic ones) can form if a body like Pluto is has a dynamic geology? Is it possible that the organic precursors for life are constantly accumulating on icy bodies like Pluto, and while obviously, live can't form on Pluto, could an impact discharge a massive quantity of precursor chemistry onto a planet more hospitable? Its an interesting aside that pretty much imminently after the earths surface solidified and cooled after the impact even, life began.

dumbfoundded 7y ago
Not an expert here at all but asteroids often do carry precursors for life. Asteroids on Earth have been found carrying organic compounds: https://www.smithsonianmag.com/science-nature/the-building-blocks-of-life-may-have-come-from-outer-space-3884354/ https://www.smithsonianmag.com/science-nature/the-building-b...
- RosanaAnaDana 7y ago
  Sure, but my point here isn't about presence, but quantity. We've known that radiation can cause the creation of bio-molecules and precursor molecules for a very long time. But there almost no way that process can generate a significant enough quantity of these molecules to really seed planets. Largely its about concentration gradients, which is why I personal have found arguments about life forming via early oceans unconvincing. A couple asteroids (or even hundreds) worth of bio-molecules spread out over an ocean, is still basically nothing. You have to have enough material concentrated in a small enough space; you need a thermodynamic process that postpones equilibrium; then you need a gradient to drive the formation of more and more complicated molecules. Like, Pluto type objects are far and away more common then earthlike objects. If there is a process that can accumulate bio-molecules in mass on these types of bodies, that's pretty game changing.
photojosh 7y ago
You've probably read 'The Vital Question'? [0] I thoroughly enjoyed it and the theory presented that life originated on alkaline marine vents where there were natural energy gradients that could be exploited. > Its an interesting aside that pretty much imminently after the earths surface solidified and cooled after the impact even, life began. So when I read this, it makes me want to read more about how these conditions could have been set up. Can you point me towards a good read(s) on this pre-life stage of Earth? [0] https://www.goodreads.com/book/show/26530386-the-vital-question https://www.goodreads.com/book/show/26530386-the-vital-quest...
- RosanaAnaDana 7y ago
  No I've not read that. My background is in botany and I took coursework in evolutionary biology and evolutionary theory. Its much more technical than the book you referenced, but I highly recommend: https://www.amazon.com/Not-Design-Retiring-Darwins-Watchmaker/dp/0520271297 https://www.amazon.com/Not-Design-Retiring-Darwins-Watchmake... Warning: this book is very much oriented towards a technical discussion in evolutionary biology. Its not really built for entertainment.
  - photojosh 7y ago
    That does look intense. Will add it to the reading list, slot it in after https://www.goodreads.com/book/show/10955059-incomplete-nature https://www.goodreads.com/book/show/10955059-incomplete-natu... – which has been slow-going. However, a quick browse of the TOC and first pages suggests it wasn't quite what I was angling for with my question to you. I had in mind a discussion on the conditions required for abiogenesis, rather than subsequent evolution. Thanks.

dumbfoundded 7y ago

Not an expert here at all but asteroids often do carry precursors for life. Asteroids on Earth have been found carrying organic compounds: https://www.smithsonianmag.com/science-nature/the-building-blocks-of-life-may-have-come-from-outer-space-3884354/ https://www.smithsonianmag.com/science-nature/the-building-b...

RosanaAnaDana 7y ago
Sure, but my point here isn't about presence, but quantity. We've known that radiation can cause the creation of bio-molecules and precursor molecules for a very long time. But there almost no way that process can generate a significant enough quantity of these molecules to really seed planets. Largely its about concentration gradients, which is why I personal have found arguments about life forming via early oceans unconvincing. A couple asteroids (or even hundreds) worth of bio-molecules spread out over an ocean, is still basically nothing. You have to have enough material concentrated in a small enough space; you need a thermodynamic process that postpones equilibrium; then you need a gradient to drive the formation of more and more complicated molecules. Like, Pluto type objects are far and away more common then earthlike objects. If there is a process that can accumulate bio-molecules in mass on these types of bodies, that's pretty game changing.

photojosh 7y ago

You've probably read 'The Vital Question'? [0] I thoroughly enjoyed it and the theory presented that life originated on alkaline marine vents where there were natural energy gradients that could be exploited. > Its an interesting aside that pretty much imminently after the earths surface solidified and cooled after the impact even, life began. So when I read this, it makes me want to read more about how these conditions could have been set up. Can you point me towards a good read(s) on this pre-life stage of Earth? [0] https://www.goodreads.com/book/show/26530386-the-vital-question https://www.goodreads.com/book/show/26530386-the-vital-quest...

RosanaAnaDana 7y ago
No I've not read that. My background is in botany and I took coursework in evolutionary biology and evolutionary theory. Its much more technical than the book you referenced, but I highly recommend: https://www.amazon.com/Not-Design-Retiring-Darwins-Watchmaker/dp/0520271297 https://www.amazon.com/Not-Design-Retiring-Darwins-Watchmake... Warning: this book is very much oriented towards a technical discussion in evolutionary biology. Its not really built for entertainment.
- photojosh 7y ago
  That does look intense. Will add it to the reading list, slot it in after https://www.goodreads.com/book/show/10955059-incomplete-nature https://www.goodreads.com/book/show/10955059-incomplete-natu... – which has been slow-going. However, a quick browse of the TOC and first pages suggests it wasn't quite what I was angling for with my question to you. I had in mind a discussion on the conditions required for abiogenesis, rather than subsequent evolution. Thanks.