4 ms·

TL;DR: With existing technology it’s tough to detect oxygen on smaller far-away planets. However, what we could instead look for is a combination of gases that

TL;DR: With existing technology it’s tough to detect oxygen on smaller far-away planets. However, what we could instead look for is a combination of gases that likely means presence of life on earlier stages, before oxygen becomes abundant in the atmosphere. (The assumption is that the alien life we might find would likely be on early stages of development anyway.) This research is about how such a combination of gases—lots of carbon dioxide, methane, and no carbon monoxide—can be detected and told apart from possible nonliving sources. The new approach should be viable to apply using Webb telescope on smaller planets like the ones in TRAPPIST-1 system.

pecg 9y ago
I'm not a scientist by any means, but since childhood when I was first exposed to the fact that life on Earth needs oxygen (and many other things, in extremely basic terms) to exist, I've been thinking to myself what if there are other distant planets where life has bootstrapped itself from completely different (or maybe opposite) components and conditions. I'm sure someone with more knowledge than I in biology and physics would certainly be able to offer a good explanation or thought.
- taeric 9y ago
  I think the problem there is simply the fact that it isn't knowable. If there is a way for life to be that different, how do you look for it? My first statement is likely stronger than it needs to be. My main question back to you is, how do you look for something that you imagine may exist, but couldn't say how?
  - pecg 9y ago
    > My first statement is likely stronger than it needs to be. My main question back to you is, how do you look for something that you imagine may exist, but couldn't say how? I certainly agree with you, thus seeking for life similar than ours is the only feasible way to spend time in deep space research; we cannot look for something different, because we don't know what to look for.
    - taeric 9y ago
      My apologies on the very late response, but if you haven't read it, I recommend the book The Eerie Silence. Covers a lot of this general idea. https://smile.amazon.com/Eerie-Silence-Renewing-Search-Intelligence/dp/B00BTM75Q0 https://smile.amazon.com/Eerie-Silence-Renewing-Search-Intel...
- jbattle 9y ago
  https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemi... Silicon has a lot of chemical possibilities similar to carbon. Also methane can perform a lot of the same functions as liquid water (though at very different temperatures).
RosanaAnaDana 9y ago
I think this is a step in the right direction, but it still has the central issue that looking for oxygen rich planets (or any atmosphere with a disproportionately high quantity of some suitable agent for reduction (respiration). We didn't even get around to the whole respiration thing on this planet for quite a long time, and there's no requisite that ATP/ respiration is the direction life is going to take, and equally, in the event of some kind of reductive respiration, there's not a prerequisite that oxygen be that agent, although its a pretty good candidate.
- vanderZwan 9y ago
  > there's no requisite that ATP/ respiration is the direction life is going to take Based on the article I linked in my other comment I would say that on oxygen-rich planets, respiration is likely to happen simply because life needs to find a way to deal with it's toxicity, or perish. Although that presupposes that photosynthesis is inevitable, which also doesn't have to be true. I kind of wonder how much we truly know about the strength of lock-in effects of evolution - of how much life is "stuck" with old hacks that we can no longer get rid of or that lead to dead ends. I doubt we'd ever evolve avian lungs from where we are now, for example. I know there are examples like that all over the place, but just how strong is the effect?
  - plushpuffin 9y ago
    As one example on a physical rather than a chemical level, I read that marsupials are stuck for this reason. They need claws to climb into their mother's pouch after birth, so there are certain ecological niches closed off to them. You'll never see a hoofed marsupial, for example.
    - plushpuffin 9y ago
      Found a source: https://synapsida.blogspot.com/2011/11/why-marsupials-cant-fly.html https://synapsida.blogspot.com/2011/11/why-marsupials-cant-f...
      - 9y ago

pecg 9y ago

I'm not a scientist by any means, but since childhood when I was first exposed to the fact that life on Earth needs oxygen (and many other things, in extremely basic terms) to exist, I've been thinking to myself what if there are other distant planets where life has bootstrapped itself from completely different (or maybe opposite) components and conditions. I'm sure someone with more knowledge than I in biology and physics would certainly be able to offer a good explanation or thought.

taeric 9y ago
I think the problem there is simply the fact that it isn't knowable. If there is a way for life to be that different, how do you look for it? My first statement is likely stronger than it needs to be. My main question back to you is, how do you look for something that you imagine may exist, but couldn't say how?
- pecg 9y ago
  > My first statement is likely stronger than it needs to be. My main question back to you is, how do you look for something that you imagine may exist, but couldn't say how? I certainly agree with you, thus seeking for life similar than ours is the only feasible way to spend time in deep space research; we cannot look for something different, because we don't know what to look for.
  - taeric 9y ago
    My apologies on the very late response, but if you haven't read it, I recommend the book The Eerie Silence. Covers a lot of this general idea. https://smile.amazon.com/Eerie-Silence-Renewing-Search-Intelligence/dp/B00BTM75Q0 https://smile.amazon.com/Eerie-Silence-Renewing-Search-Intel...
jbattle 9y ago
https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemi... Silicon has a lot of chemical possibilities similar to carbon. Also methane can perform a lot of the same functions as liquid water (though at very different temperatures).

RosanaAnaDana 9y ago

I think this is a step in the right direction, but it still has the central issue that looking for oxygen rich planets (or any atmosphere with a disproportionately high quantity of some suitable agent for reduction (respiration). We didn't even get around to the whole respiration thing on this planet for quite a long time, and there's no requisite that ATP/ respiration is the direction life is going to take, and equally, in the event of some kind of reductive respiration, there's not a prerequisite that oxygen be that agent, although its a pretty good candidate.

vanderZwan 9y ago
> there's no requisite that ATP/ respiration is the direction life is going to take Based on the article I linked in my other comment I would say that on oxygen-rich planets, respiration is likely to happen simply because life needs to find a way to deal with it's toxicity, or perish. Although that presupposes that photosynthesis is inevitable, which also doesn't have to be true. I kind of wonder how much we truly know about the strength of lock-in effects of evolution - of how much life is "stuck" with old hacks that we can no longer get rid of or that lead to dead ends. I doubt we'd ever evolve avian lungs from where we are now, for example. I know there are examples like that all over the place, but just how strong is the effect?
- plushpuffin 9y ago
  As one example on a physical rather than a chemical level, I read that marsupials are stuck for this reason. They need claws to climb into their mother's pouch after birth, so there are certain ecological niches closed off to them. You'll never see a hoofed marsupial, for example.
  - plushpuffin 9y ago
    Found a source: https://synapsida.blogspot.com/2011/11/why-marsupials-cant-fly.html https://synapsida.blogspot.com/2011/11/why-marsupials-cant-f...
    - 9y ago