2. Origin of Life?
⦿ Panspermia - life reached earth from outer
space
› Svante Arrhenius – Swedish chemist, 1908
⦿ Directed Panspermia
› Francis Crick, Orgel, 1973
⦿ Merely switches the problem from one
location
⦿ Plus there is considerable evidence that life
did begin on earth from abiotic beginnings
3. Solar System Debris
⦿ Why do comets and asteroids exist?
Well the Solar System formation is a messy process……
4. Solar System Debris
⦿ During the accretion of the planets, bits of matter come
together to form larger aggregates, sweep up and fling out
most of the debris but stable/protected zone remain
5. Solar System Debris
⦿ Molecules From dense molecular clouds aggragate
⦿ Forming Asteroids in the Protosolar Nebula
The Asteroid
Belt (rocky,
between
Jupiter and Mars)
The
Edgeworth/Kuiper
Belt (beyond
Neptune) and Oort
Cloud (way out
there) – sources of
comets (icy)
⦿ Primarily found in two zones of the solar system
6. Accretion Phase
⦿ Last for Millions of years
⦿ Consideral amount of Chemistry to occur
› In Gas Phase, on ice, and mineral grain surfaces
7. Solar System Debris: Asteroids
⦿ Products of these reactions
increase size
⦿ Secondary alteration
event
⦿ Differentiations
› Jupiter interference of
planet formation
between Mars and
Jupiter- the debris
asteroid belt
8. Opportunity for Additional
Chemical Reactions
⦿ Jupiter stirred up the
planetesimals so that
collisions were violent
rather than gentle.
⦿ Heating(Impact Shocks)
› Thermal metamorphism
⦿ Molten Core (Melting)
› Aqueous alteration
⦿ Radiogenic Decay
› 60Fe and 26Al
9. Perfect conditions for Chemistry
to Occur
⦿ Drive formation of complex organics from
a interstellar precursor.
10. Solar System Debris: Asteroids
⦿ The original “parent bodies” that were the
predecessors of the asteroids that were large
enough to differentiate.
› some asteroids are metallic, consisting of the core
fragments of a large parent body.
› the largest asteroids may be intact parent bodies.
11. Asteroids
⦿ Asteroids are small, rocky, cratered and
irregularly shaped.
› They are the collisionally
modified remains of leftover
planetesimals parent bodies
with over 4.5 billion years of
physical and chemical effects
12. Asteroid and Meteorites
› Delivery vehicles
that impact the
Earth with 40
million kg of
cosmic material
a year
⦿ Meteorites are just small Asteroids.
⦿ Products of collisions that had occurred
within that had fallen to the Earth.
13. Meteorites
⦿ Three Overall
Categories
› Stony
› Iron
› Stony-Iron
⦿ Three Overall
Categories
› Stony
› Iron
› Stony-Iron
⦿ Many organic compounds have been
found
⦿ sugar acids, hydroxy acids, aldehydes,
ketones, and amines, but
14. Amino Acids
⦿ Building Blocks of Proteins and
Nucleobases
› DNA and RNA
⦿ Analytical techniques
› isolation and Analysis
⦿ Chiral
› Abiotic 50/50 racemic,
› Biotic exclusive L
⦿ Rule out possible contamination
15. Carbonaceous Chondrites
⦿ Petrographic types based on physical and
chemical environment in the parent body
⦿ (1) strong aqueous alterations
› CI < CM2 < CR2
⦿ (6) strong thermal metamorphism
› CO3 < CV3
16. Average total amino acid abundances (top) and structural distributions of amine position
in C5 amino acids (bottom) in carbonaceous chondrites vary greatly with class and
petrographic type. Structural distributions are shown as relative abundances of isomers of
C5 amino acids, normalized to the total number of possible isomers (i.e., random
selection of amine position during formation should produce 25% each of α, β, γ, and δ
isomers in this plot).
17. Different Amino Acid
Formation
⦿ Abiotic amino acid formation chemistry
Strongly dependent on
› Availability of amino acid precursors
› Temperature
› Water activity
› Mineralogical composition of parent body
⦿ Which influence these factors
› Structural enantiomeric
› Isotopic composition of meteoritic amino acids
⦿ Thus there must be multiple formations
synthetic routes for amino acids
18. Multiple Pathways
⦿ Mostly analyzed Strecker-
Cyanohydrin synthesis
generally responsible for
increase α-amino acids
abundances
› aqueously altered
meteorites
› Formation outside of
parent body
⦿ Yet Micheal Addition for an
abundance of β-amino
acids
› Formed stable lactams
that were hydrolyzed to
γ-, δ- amino acids
› That were protected from
thermal degradation
19. Focus on Fischer-Tropsch
Synthesis
⦿ Commonly used in Industry
⦿ Used in WWII during fuels shortages
⦿ FT synthesis
› Involves low temperature <300oC
› Catalytic reaction of H2, CO, NH3 gas
› Mineral-surface catalyzed metals Fe, Co, Ni
⦿ All of which are found in abundance in
early solar nebulas
20. Problem
⦿ Is it possible that molecules, H2, H2O, N2,
NH3, CO, or more complex organic
molecules synthesized in the solar nebula
became trapped in parent bodies
asteroid during the accretion process.
⦿ This closed system under went thermal
alteration served to “recylce” the atoms
that served as feedstock for mineral
catalyzed FT type reactions.
21. Future Direction
⦿ Exploratory experiments aimed to
determine nitrogen-bearing organic
compounds undergoing surface mediated
FTT catalyzed reactions on grain surface in
the protosolar nebula.
⦿ A novel organic analysis using magnetite
catalyst to produce nitrogen containing FTT
products found with varying reaction
temperatures and number of experimental
cycles.
22. Instrumentation
⦿ PY-GCMS consist of CDS pyroprobe
(5200 model) coupled to a Thermo Trace
1310 gas chromatograph with a Thermo
ISQ mass spectrometer.
23. Experimental Plan
⦿ The Pyrolysis procedure would involve initial
experiments using thermally desorbed volatile
compounds that will gently pyrolyze
macromolecular materials containing nitrogen
at 300oC for 10 minutes.
⦿ During the heating duration released
compounds will be trapped at room
temperature then thermally desorbed and
injected single pulse into GC for separation
and subsequent detection by MS.
⦿ Isotopic distributions of organic compounds
have been and can be identified using this
method.
24. Expected Difficulties
⦿ Contamination any organic residue
› Possible mitigation
● Wrap all sample handling tools, ceramics,
glassware in aluminum foil and heat in air at 500oC
overnight
⦿ Extraction techniques
› Almost always involves hot-water extraction
followed by acid hydrolysis
● Pyrolysis will circumvent aqueously altered free
amino acids that might be precursors
⦿ High heat pyrolysis will degrade amino
acids
25. Conclusion
⦿ A quantitative study of laboratory-
produced FTT amino acids will be
presented here.
⦿ These test will be compared to thermally
altered meteorites to support the
mechanism consistent with predominant
amino acid formation.
26. References
1. Abreu, N.M., Primitive Meteorites and Asteroids: Physical, Chemical, and Spectroscopic Observations
Paving the Way to Exploration. 2018: Elsevier.
2.Burton, A.S., et al., A propensity for n-ω-amino acids in thermally altered Antarctic meteorites.
Meteoritics & Planetary Science, 2012. 47(3): p. 374-386.
3.Burton, A.S., et al., Understanding prebiotic chemistry through the analysis of extraterrestrial amino
acids and nucleobases in meteorites. Chemical Society Reviews, 2012. 41(16): p. 5459-5472.
4.Elsila, J.E., et al., Meteoritic amino acids: Diversity in compositions reflects parent body histories. ACS
Central Science, 2016. 2(6): p. 370-379.
5.Glavin, D.P., et al., The Search for Chiral Asymmetry as a Potential Biosignature in our Solar System.
Chemical reviews, 2019.
6.Johnson, N., M. McCarthy, and J. Nuth. Rate comparisons of magnetite and iron catalysts during
Fischer-Tropsch-type reactions. in Lunar and Planetary Science Conference. 2014.
7.Johnson, N.M., A. Burton, and J. Nurth III, Meteorites, Organics and Fischer-Tropsch Type Reaction:
Production and Destruction. 2011.
8.Locke, D.R., et al., Organic Analysis of Catalytic Fischer-Tropsch Synthesis Products and Ordinary
Chondrite Meteorites by Stepwise Pyrolysis-GCMS: Organics in the Early Solar Nebula. 2014.
9.Locke, D.R., et al., Pyrolysis-GCMS Analysis of Solid Organic Products from Catalytic Fischer-Tropsch
Synthesis Experiments. 2015.
10.Nuth, J. and N.M. Johnson, Transformation of Graphitic and Amorphous Carbon Dust to Complex
Organic Molecules in a Massive Carbon Cycle in Protostellar Nebulae. Meteoritics and Planetary
Science Supplement, 2012. 75.
11.Pizzarello, S., Catalytic syntheses of amino acids and their significance for nebular and planetary
chemistry. Meteoritics & Planetary Science, 2012. 47(8): p. 1291-1296.
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Synthesis Products: Are they Similar to Organics in Chondritic Meteorites? 2014.
