Meteorites reveal another way to make life's components

Mar 09, 2012 by Bill Steigerwald
A meteorite is analyzed in the study at its collection site in Antarctica. Credit: Antarctic Search for Meteorites program, Case Western Reserve University

(PhysOrg.com) -- Creating some of life's building blocks in space may be a bit like making a sandwich – you can make them cold or hot, according to new NASA research. This evidence that there is more than one way to make crucial components of life increases the likelihood that life emerged elsewhere in the Universe, according to the research team, and gives support to the theory that a "kit" of ready-made parts created in space and delivered to Earth by impacts from meteorites and comets assisted the origin of life.

In the study, scientists with the Astrobiology Analytical Laboratory at NASA's Goddard Space Flight Center in Greenbelt, Md., analyzed samples from fourteen carbon-rich meteorites with minerals that indicated they had experienced high temperatures – in some cases, over 2,000 degrees Fahrenheit. They found amino acids, which are the of proteins, used by life to speed up chemical reactions and build structures like hair, skin, and nails.

Previously, the Goddard team and other researchers have found amino acids in carbon-rich meteorites with mineralogy that revealed the amino acids were created by a relatively low-temperature process involving water, aldehyde and ketone compounds, ammonia, and cyanide called "Strecker-cyanohydrin synthesis."

"Although we've found amino acids in carbon-rich meteorites before, we weren't expecting to find them in these specific groups, since the high temperatures they experienced tend to destroy amino acids," said Dr. Aaron Burton, a researcher in NASA's Postdoctoral Program stationed at NASA Goddard. "However, the kind of amino acids we discovered in these meteorites indicates that they were produced by a different, high-temperature process as their parent asteroids gradually cooled down." Burton is lead author of a paper on this discovery appearing March 9 in Meteoritics and Planetary Science.

In the new research, the team hypothesizes the amino acids were made by a high-temperature process involving gas containing hydrogen, carbon monoxide, and nitrogen called "Fischer-Tropsch" –type reactions. They occur at temperatures ranging from about 200 to 1,000 degrees Fahrenheit with minerals that facilitate the reaction. These reactions are used to make synthetic lubricating oil and other hydrocarbons; and during World War II, they were used to make gasoline from coal in an attempt to overcome a severe fuel shortage.

Researchers believe the parent asteroids of these meteorites were heated to high temperatures by collisions or the decay of radioactive elements. As the asteroid cooled, Fischer-Tropsch-type (FTT) reactions could have happened on mineral surfaces utilizing gas trapped inside small pores in the asteroid.

FTT reactions may even have created amino acids on dust grains in the solar nebula, the cloud of gas and dust that collapsed under its gravity to form the solar system. "Water, which is two hydrogen atoms bound to an oxygen atom, in liquid form is considered a critical ingredient for life. However, with FTT reactions, all that's needed is hydrogen, carbon monoxide, and nitrogen as gases, which are all very common in space. With FTT reactions, you can begin making some prebiotic components of life very early, before you have asteroids or planets with liquid water," said Burton.

In the laboratory, FTT reactions produce amino acids, and can show a preference for making straight-chain molecules. "In almost all of the 14 meteorites we analyzed, we found that most of the amino acids had these straight chains, suggesting FTT reactions could have made them," said Burton.

It's possible that both Strecker and FTT processes could have contributed to the supply of amino acids in other meteorites. However, evidence for the FTT reaction would tend to get lost because FTT reactions create them in much lower abundances than Strecker synthesis. If an asteroid with an initial amino acid supply from FTT reactions was later altered by water and Strecker synthesis, it would overwrite the small contribution from the FTT reactions, according to the team.

The team believes the majority of the amino acids they found in the 14 meteorites were truly created in space, and not the result of contamination from terrestrial life, for a few reasons. First, the amino acids in life (and in contamination from industrial products) are frequently linked together in long chains, either as proteins in biology or polymers in industrial products. Most of the amino the amino acids discovered in the new research were not bound up in proteins or polymers. In addition, the most abundant amino acids found in biology are those that are found in proteins, but such "proteinogenic" amino acids represent only a small percentage of the amino acids found in the meteorites. Finally, the team analyzed a sample of ice taken from underneath one of the meteorites. This ice had only trace levels of amino acids suggesting the meteorites are relatively pristine.

The experiments showing FTT reactions produce amino acids were performed over 40 years ago. The products have not been analyzed with modern techniques, so the exact distributions of amino acid products have not been determined. The team wants to test FTT reactions in the laboratory using a variety of ingredients and conditions to see if any produce the types of amino acids with the abundances they found in the 14 meteorites.

The team also wants to expand their search for amino acids to all known groups of carbon-rich meteorites. There are eight different groups of carbon-rich meteorites, called "carbonaceous chondrites." The new work adds two additional groups to the three previously known to have produced amino acids, leaving three groups to be tested. These three remaining groups have a high metal content as well as evidence for . "We'll see if they have amino acids also, and hopefully gain some insight into how they were made," says Burton. When the team began looking for amino acids in carbon-rich meteorites, it was considered somewhat of a long shot, but now: "We would be surprised if we didn't discover in a carbon-rich ," says Burton.

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foofighter
Mar 09, 2012
This comment has been removed by a moderator.
Au-Pu
2 / 5 (6) Mar 09, 2012
It is interesting that there appears to be a natural drive in nature for the development of living matter and once alive the next drive appears to be the development of intelligence.
Could an early Indian researcher, recognised by the British have held part of the answer?
Bose, late 19th and early 20th centuries proposed that intelligence was a molecular property of all matter.
He conducted some very interesting experiments that were abandoned after his death.
But rather than molecular could it be a sub atomic property?
An interesting thought.
Skultch
5 / 5 (3) Mar 09, 2012
Probably old news to some, but I just found out that we have even found nucleobases (adenine and guanine in DNA) in asteroids and we are pretty sure those were created in space, too.

http://www.nasa.g...tes.html

Zeus is superfluous. :)
210
1 / 5 (1) Mar 09, 2012
It is interesting that there appears to be a natural drive in nature for the development of living matter and once alive the next drive appears to be the development of intelligence.
Could an early Indian researcher, recognised by the British have held part of the answer?
Bose, late 19th and early 20th centuries proposed that intelligence was a molecular property of all matter.
He conducted some very interesting experiments that were abandoned after his death.
But rather than molecular could it be a sub atomic property?
An interesting thought.

Indeed: To see intelligence at work, we stand apart and witness it in others -Observation. If it is in all things,even in death we could not stand far enough away to witness it be drawn or emitting from any source or influencing an event...Dark Matter, Dark energy, our science in search of the awesome Higgs Particle, etc, etc, etc...our 'experiments' are becoming so complex and economically challenging that we may, MAY, cont:
210
1 / 5 (1) Mar 09, 2012
cont - have to gut our military budgets, or more, to fund the secrets we may be bumping up against! Would that effort, qualify humanity as a candidate for its own Nobel Prize? We put aside our differences and forge a worldwide alliance to break through these colossal barriers to higher thought and near-supreme understanding?!? Once solved, would these ancient riddles provide humanity with access to such resources as we once thought could never be obtained? Proving these 'truths' may be the key that unlocks the shackles on our own minds. Consider it, just what would a human(race) look like that had suddenly and intentionally stepped around its own bias, JUST ENOUGH, to pull a solution from eternity with such far reaching implications: Universal Intelligence. We now know that even empty space is not empty: http://www.youtub...261F0EA6 an idea we would never have mentioned out loud 35 years ago.

word-to-ya-muthas
Pooua
1 / 5 (1) Mar 09, 2012
It is interesting that we have found these processes for creating amino acids, but I feel that stating that these are life's ingredients is vague and misleading. We have never yet seen life develop from any mass of amino acids, and it probably doesn't happen that way. Amino acids and proteins at most form the shell of life; they do not constitute life on their own. So, we are no closer to discovering how life could form spontaneously than we were prior to the discoveries. This is merely an interesting chemical discovery.
Callippo
1 / 5 (2) Mar 10, 2012
In steady state Universe model of AWT it would be rather surprising, if the life wouldn't evolve many times somewhere else and seeded the terrestrial life after long travel across cosmic space, as Fred Hoyle considered already before many years.
Callippo
not rated yet Mar 10, 2012
Bose, late 19th and early 20th centuries proposed that intelligence was a molecular property of all matter. He conducted some very interesting experiments that were abandoned after his death.
Do you have some link to these experiments? Speculations and theories are one thing, but experiments are what is crucial here.
Mastoras
5 / 5 (1) Mar 18, 2012
Bose, late 19th and early 20th centuries proposed that intelligence was a molecular property of all matter


This "molecular property of matter" is a bit inexact and fuzzy. But whoever was this Bose, the same thing is also stated by the philosophy of materialism (Vladimir Lenin, "Materialism and Empiricism", or something like that. There might be something newer, but I dont know it).

...an early Indian researcher, recognised by the British ... He conducted some very interesting experiments that were abandoned after his death.


"Recognized by the British" is not how we normaly state the fact that someone was a credible scientist. A recognized and credible contribution doesn't become forgoten after someone's death. So, I think I hear the sound of pseudo-science here.

India is an ancient country with very rich culture. But here I seem to hear the sound of Hindu pseudo-science.

rather than molecular could it be a sub atomic property? An interesting thought.


How?