IJAA  Vol.3 No.3 , September 2013
The Effect of Radiogenic Heating on the Amino Acid Content of an Early Cometary Body
Author(s) Carlo Canepa
ABSTRACT

This study compares the rates for the formation and destruction of amino acids in the liquid cometary core subjected to radiogenic heating by the β+ decay of the cosmogenic nuclide 26Al. The evolution of the temperature and mass of the comet were computed along with the dynamics of relatively complex organic species such as amino acids. Given the experimentally determined rate coefficient for the radiolysis of amino acids in water solution, the destruction of amino acids is virtually completed after an absorbed radiation dose of ~1 kGy. The calculations suggest that the liquid water core in comets with an initial radionuclide abundance that is sufficient to crystallize and melt the original amorphous ice is subjected to a dose of 100 - 1500 kGy. Any amino acid concentration formed in water either by radiolysis of simpler compounds or by thermal processes such as the synthesis of Strecker could not survive the irradiation delivered by the decay of 26Al.


Cite this paper
C. Canepa, "The Effect of Radiogenic Heating on the Amino Acid Content of an Early Cometary Body," International Journal of Astronomy and Astrophysics, Vol. 3 No. 3, 2013, pp. 278-284. doi: 10.4236/ijaa.2013.33033.
References
[1]   J. T. Wickramasinghe, N. C. Wickramasinghe and M. K. Wallis, “Liquid Water and Organics in Comets: Implications for Exobiology,” International Journal of Astrobiology, Vol. 8, No. 4, 2009, pp. 281-290. 0Hdoi:10.1017/S1473550409990127

[2]   T. P. Kohman, “Aluminum-26: A Nuclide for All Seasons,” Journal of Radioanalytical and Nuclear Chemistry, Vol. 219, 1997, pp. 165-176. 1Hdoi:10.1007/BF02038496

[3]   D. Prialnik, A. Bar-Nun and M. Podolak, “Radiogenic Heating of Comets by 26Al and Implications for Their Time of Formation,” Astrophysical Journal, Vol. 319, 1987, pp. 993-1002. 2Hdoi:10.1086/ 165516

[4]   D. Prialnik and M. Podolak, “Radioactive Heating of Porous Comet Nuclei,” Icarus, Vol. 117, No. 2, 1995, pp. 420-430. 3Hdoi:10.1006/icar.1995.1166

[5]   D. Prialnik and M. Podolak, “Changes in the Structure of Comet Nuclei Due to Radioactive Heating,” Space Science Reviews, Vol. 90, No. 1-2, 1999, pp. 169-178. 4Hdoi:10.1023/A:1005202215579

[6]   J. Llorca, “Organic Matter in Comets and Cometary Dust,” International Microbiology, Vol. 8, No. 1, 2005, pp. 5-12.

[7]   H. Mita, N. Shirakura, H. Yokoyama, S. Nomoto and A. Shimoyama, “Kinetic Study of Abiotic Amino Acid Formation by UV-Irradiation,” Advances in Space Research, Vol. 33, No. 8, 2004, pp. 1282-1288. 5Hdoi:10.1016/j.asr.2003.08.035

[8]   M. Trojanowicz, A. Bojanowska-Czajka, G. Kciuk, K. Bobrowski, M. Gumiela, A. Koc, G. Na??cz-Jawecki, M. Torun and D. S. Ozbay, “Application of Ionizing Radiation in Decomposition of Selected Organic Pollutants in Waters,” European Water, Vol. 39, 2012, pp. 15-26.

[9]   G. Matrajt, S. Pizzarello, S. Taylor and D. Brownlee, “Concentration and Variability of the AIB Amino Acid in Polar Micrometeorites: Implications for the Exogenous Delivery of Amino Acids to the Primitive Earth,” Meteoritics & Planetary Science, Vol. 39, No. 11, 2004, pp. 1849-1858. 6Hdoi:10.1111/j.1945-5100.2004.tb00080.x

[10]   M. Maurette, “Micrometeorites and the Mysteries of Our Origin,” Springer, Berlin Heidelberg, Berlin, 2006, p. 126. 7Hdoi:10.1007/3-540-34335-0

[11]   A. G. Yeghikyan, “Theoretical Investigation of Cosmic Ray Processing of Solar System Ices,” Astrophysics and Space Sciences Transactions, Vol. 4, No. 2, 2008, pp. 47-50. 8Hdoi:10.5194/astra-4-47-2008

[12]   F. Cataldo, G. Angelini, S. Iglesias-Groth and A. Manchado, “Solid State Radiolysis of Amino Acids in an Astrochemical Perspective,” Radiation Physics and Chemistry, Vol. 80, No. 1, 2011, pp. 57-65. 9Hdoi:10.1016/j.radphyschem.2010.08.012

[13]   P. A. Gerakines, R. L. Hudson, M. H. Moore and J.-L. Bell, “In Situ Measurements of the Radiation Stability of Amino Acids at 15-140 K,” Icarus, Vol. 220, No. 2, 2012, pp. 647-659. 10Hdoi:10.1016/ j.icarus.2012.06.001

[14]   R. Merk and D. Prialnik, “Early Thermal and Structural Evolution of Small Bodies in the Transneptunian Zone,” Earth, Moon Planets, Vol. 92, No. 1, 2003, pp. 359-374. 11Hdoi:10.1023 / B:MOON.0000031952.89891.a4

[15]   T. Ghaffar and A. W. Parkins, “The Catalytic Hydration of Nitriles to Amides Using a Homogeneous Platinum Phosphinito Catalyst,” Journal of Molecular Catalysis A: Chemical, Vol. 160, No. 2, 2000, pp. 249-261. 12Hdoi:10.1016/S1381-1169(00)00253-3

[16]   M. Maurette, J. Duprat, C. Engranda, M. Gounellea, G. Kuratc, G. Matrajta and A. Toppanid, “Accretion of Neon, Organics, CO2, Nitrogen and Water from Large Interplanetary Dust Particles on the Early Earth,” Planetaryand Space Science, Vol. 48, No. 11, 2000, pp. 1117-1137. 13Hdoi:10.1016/S0032-0633(00)00086-6

[17]   A. Rimola, M. Sodupe and P. Ugliengo, “Deep-Space Glycine Formation via Strecker-Type Reactions Activated by Ice Water Dust Mantles. A Computational Approach,” Physical Chemistry Chemical Physics, Vol. 12, No. 20, 2010, pp. 5285-5294. 14Hdoi:10.1039/b923439j

 
 
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