Chirality - causes and observations including in space

[newtonian]

Have there been any observations of chirality in space?<br /><br />Would chirality be considered a marker for life?<br /><br />What might have caused chiraltiy in the origin of earth-life?<br /><br />Specifically, what chiral complex molecules have been detected in space, if any?

 

[kmarinas86]

http://www.panspermia.org/whatsne32.htm<br /><br /><font color="yellow">23 February 2004<br />Chirality from space? Maybe. Life as we know it employs only left-handed protein and right-handed sugar molecules. If life arose on this planet from random, nonliving chemicals, the exclusive chirality it now observes is puzzling. How did life get that way? Now Sandra Pizzarello of Arizona State University, and Arthur L. Weber of the SETI Institute suggest that the modest chirality in meteorites could explain the puzzle. "The delivery of material from outer space via meteorites - despite the seeming randomness and complexity of these materials - could in fact have 'pushed' chemical evolution on Earth toward homochirality."<br />We welcome this elaboration on pseudo-panspermia by two veteran astrobiologists. Of course, we believe the chirality in meteorites derives from past life on their parent bodies.</font>/safety_wrapper>

 

[h9c2]

It is not chirality in itself that is remarkable. But finding a population of complex molecules that is homochiral would certainly raise many eyebrows.

 

[newtonian]

kmarinas86 - Your link led to this link:<br /><br />http://www.panspermia.org/chiral.htm<br /><br />Concerning a slight preference for L-amino acids on the Murcheson meteorite.<br /><br />I will study it before responding.<br /><br />Thank you for the link.<br /><br />Interesting that the quote you posted considers the observed slight chiralilty as a marker for previous life!<br /><br />I'm sure others feel otherwise, some non-living mechanism.

 

[newtonian]

H9C2 - Hi!<br /><br />Yes, that certainly would raise eyebrows!<br /><br />What is the name of the hydrocarbon H9C2 assuming only one structural form exists? [or, er C2H9].<br /><br />I know C2H6 is ethane, have two methyls (CH3's). C2H9 would be 3 methyls with a carbon removed.<br /><br />Just curious about your user name.

 

[h9c2]

Keep in mind though that a mixture of molecules that is not completely racemic could have natural causes. (polarized UV light destroys molecules with different rotations at different rates.)<br />Nonetheless, I believe that the complete absence of one rotation would be a strong biomarker.

 

[newtonian]

H9C2 - rotations? I assume you mean orientations, or do I misunderstand the process?<br /><br />UV irradiation is a problem for chemical evolution scenarios since it destroys many molecules on chemical pathways to life from non-life.<br /><br />Is this the cause of slight chirality on the Murcheson meteorite, or is it more along the lines of synthesis factors rather than destruction factors?<br /><br />I had heard that a certain type of quartz crystal slightly favors synthesis of L-amino acids - I hope someone will help me document the details of all of this!<br /><br />I know it may not simply be a matter of destruction vs. synthesis.<br /><br />It may be synthesis + destruction + synthesis + destruction in a long chain of events.<br /><br />Say, for example, upwelling water currents or atmospheric currents or both going from a zone of synthesis to a zone of protection from UV and involving contact with crystal catalysts (say quartz for example).<br /><br />The Biblical hint I am pursuing is:<br /><br />(Genesis 1:2) 2 Now the earth proved to be formless and waste and there was darkness upon the surface of [the] watery deep; and God’s active force was moving to and fro over the surface of the waters. . .<br /><br />Why surface of the waters and why in darkness if indeed the energy (invisible active force, Hebrew ruahh, informationally directed energy in this case) was creating life and complex pre-biotic molecules?<br /><br />I suspect it is because the surface of early earth's primordial waters was an interface with both water currents involving upwelling, and atmospheric currents involving entry into a upper atmosphere synthesis environment plus despostion of molecules via panspermia (accretion) on earths watery surface.<br /><br />Just a guess, btw.<br /><br />[There are other Biblical leads I am following on the origin of life, btw, if you are interested. {clues: methods of accretion of dust and water on early earth - and how this may have favored chirality - see Job 38:9; 2 Peter 3

 

[newtonian]

H9C2 - Yes, I agree that chirality "would be a strong biomarker" as per your post.<br /><br />Have we found any such biomarkers in space?