Implications of life being found or not found on Europa

[1oldman2]

Greetings and happy memorial day,
I wonder what effect or consequence the intense radiation found in the Europa environment would have on the development of life there. I haven't noticed that factored into the odds.

 

[rootone]

How much of the intense radiation around Jupiter can penetrate through Europa's ice crust though?
I think probably it's not much.

 

[Buzz Bloom]

Hi Dr Wu:

I think I failed to make my question clear. Maybe it will help if I explain my orientation.
1. I believe it is always impossible to ever be certain about any negative.
2. Any phenomenon that may be considered to be plausibly possible is likely (e.g., probability > 50%) to exist somewhere in our infinite universe. However, if life not found to exist in our galaxy, other than on Earth, it is extremely unlikely (probability < 0.01%) it will ever be found elsewhere in the universe. I think that to make such a finding will require assessing the atmospheric components of a planet in another galaxy, and finding free oxygen gas, O₂. My guess is that will not ever be a practical possibility, even for Andromeda.
3. At the present time, I find that any possibility of life not based on carbon and water is only at most a plausible speculation. Therefore, in the absence of what might be sought for as a high likelihood indicator of success, it is not currently possible to scientifically to make any kind of probability estimate about this possibility.

So, If we ignore the possibility of certainty regarding a negative finding, suppose we assume no positive finding, and that science eventually learns a lot about the details of requirements for carbon and water based life to evolve from non-life. Then if we also assume for the purpose of this question that science makes an estimate that the likelihood of finding life based on carbon and water existing in the galaxy elsewhere than on Earth is, say < 1%.

How would that 1% estimate make you feel? At what level of probability estimate, higher or lower, would your feelings be different?

Regards,
Buzz

 

[1oldman2]

How much of the intense radiation around Jupiter can penetrate through Europa's ice crust though?
I think probably it's not much.

I'm sure that will be studied in detail when a probe arrives to penetrate the ice, until then we can extrapolate at best. The "deck" that is Europa has a lot of wild cards in it.

 

[mfb]

It doesn't matter whether the radiation can penetrate the first 1 or 10 meters, it is completely irrelevant after 100 meters, and the layer is at least several kilometers thick.

 

[1oldman2]

it is completely irrelevant after 100 meters

Thanks for the info, that would make a big difference.

 

[1oldman2]

http://www.kiss.caltech.edu/new_website/workshops/life/life.html
http://www.kiss.caltech.edu/study/life/presentations/Hud.pdf
The pdf is interesting and relative to certain post on this thread.

 

[1oldman2]

Seems more common than we thought.
http://www.space.com/33193-organic-molecule-planet-forming-disk.html
http://www.space.com/33167-twisty-chiral-molecule-first-found-interstellar-space.html

 

[Buzz Bloom]

http://www.space.com/33167-twisty-chiral-molecule-first-found-interstellar-space.html

Hi @1oldman2:

I found the articles you cited quite interesting. I found one statement in the article whose link I quoted above which "technically" contradicts something I have recent read in:

Genesis by Robert M. Hazen, p. 181.​

Quote from link (highlighting is mine):

Though the molecules are made of the same components, it's impossible to flip one around to make it exactly match the other.​

Quote from Genesis:

Glenn's research exploited the fact that although almost all of life's amino acids are left handed, as soon as an organism dies , a slow, inexorable process called racemization -- the random flipping of molecules from L to D and vice versa -- begins. Eventually, after a few tens of thousands of years an organism's amino acids will have completely randomized to a 50:50 mixture.​

Regards,
Buzz

 

[1oldman2]

Hi Buzz,
I'm not familiar with "Genesis" however I'm searching for a copy and if I'm $14.00 in the clear when the bills are paid this month I'll likely get the pdf version, looks like a very interesting read. I'm always a little suspicious of reading "breakthrough announcements" in everyday publications and it seems the one I posted was based on http://science.sciencemag.org/content/352/6292/1449 . Guess I'll have to wait and see what becomes of the contradiction. If you find anymore on this particular subject please let me know.
Thanks,

 

[Buzz Bloom]

Hi @1oldman2:

I first became interested in the origin of life when I read

English translation: Oparin, A. I. The Origin of Life. New York: Dover (1952)​

as a teenager. Since then I have read several other books on this topic, but Genesis by Hazen (2005) has become my new favorite. It is mostly a very well written autobiographical description of many laboratory experiments he and others conducted to confirm ideas about various mechanisms involved in the origin of life.

Hope you are able to get a copy. Have you investigated library resources? The copy I read was from my local town library.

Regards,
Buzz

 

[1oldman2]

Have you investigated library resources? The copy I read was from my local town library.

great suggestion, I tend to under use the local library.

 

[Ygggdrasil]

Quote from link (highlighting is mine):

Though the molecules are made of the same components, it's impossible to flip one around to make it exactly match the other.​

Quote from Genesis:

Glenn's research exploited the fact that although almost all of life's amino acids are left handed, as soon as an organism dies , a slow, inexorable process called racemization -- the random flipping of molecules from L to D and vice versa -- begins. Eventually, after a few tens of thousands of years an organism's amino acids will have completely randomized to a 50:50 mixture.​

​

These statements are both accurate and the confusion comes from the different uses of the word "flip."

The statement from the link is essentially the definition of chiratlity: molecules that cannot be superposed on their mirror images through simply rotating the molecule (i.e. "flipping the molecule around").

The Genesis quote is referring to a set of chemical reactions that can "flip" or randomize the stereochemistry of chiral molecules (often by first converting them to an achiral intermediate. An example of such a reaction is one involving the an SN1 mechanism. Because racemization involves more than just simply rotating the molecule, molecules that can undergo racemization are still considered chiral.

 

[Buzz Bloom]

The statement from the link is essentially the definition of chiratlity: molecules that cannot be superposed on their mirror images through simply rotating the molecule (i.e. "flipping the molecule around").

Hi: @Ygggdrasil:

Thank you very much for correcting my misunderstanding.

Regards,
Buzz

 

[1oldman2]

Regarding the last few posts, Thanks for the info, this site is great at clearing up misunderstandings.