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Synthesis of glycine-containing complexes in impacts of comets on early Earth


Delivery of prebiotic compounds to early Earth from an impacting comet is thought to be an unlikely mechanism for the origins of life because of unfavourable chemical conditions on the planet and the high heat from impact. In contrast, we find that impact-induced shock compression of cometary ices followed by expansion to ambient conditions can produce complexes that resemble the amino acid glycine. Our ab initio molecular dynamics simulations show that shock waves drive the synthesis of transient C–N bonded oligomers at extreme pressures and temperatures. On post impact quenching to lower pressures, the oligomers break apart to form a metastable glycine-containing complex. We show that impact from cometary ice could possibly yield amino acids by a synthetic route independent of the pre-existing atmospheric conditions and materials on the planet.

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Figure 1: The cumulative probability of impact for our simulated shock velocities.
Figure 2: Snapshots of the computational cell.
Figure 3: Simulated mass spectra of the C–N bonded molecules found during our simulations.
Figure 4: Mechanism for glycine–CO2 complex synthesis on expansion and cooling.


  1. 1

    Brack, A. From interstellar amino acids to prebiotic catalytic peptides: a review. Chem. Biodiv. 4, 665–679 (2007).

    CAS  Article  Google Scholar 

  2. 2

    Nelson, K. E., Levy, M. & Miller, S. L. Peptide nucleic acids rather than RNA may have been the first genetic molecule. Proc. Natl Acad. Sci. USA 97, 3868–3871 (2000).

    CAS  Article  Google Scholar 

  3. 3

    Barbier, B., Visscher, J. & Schwartz, A. W. Polypeptide-assisted oligomerization of analogs in dilute aqueous solution. J. Mol. Evol. 37, 554–558 (1993).

    CAS  Article  Google Scholar 

  4. 4

    Miller, S. L. A production of amino acids under possible primitive earth conditions. Science 117, 528–529 (1953).

    CAS  Article  Google Scholar 

  5. 5

    Miller, S. L. & Urey, H. C. Organic compound synthesis on the primitive earth. Science 130, 245–251 (1959).

    CAS  Article  Google Scholar 

  6. 6

    Bar-Nun, A., Bar-Nun, N., Bauer, S. H. & Sagan, C. Shock synthesis of amino acids in simulated primitive environments. Science 168, 470–473 (1970).

    CAS  Article  Google Scholar 

  7. 7

    McKay, C. P. & Borucki, W. J. Organic synthesis in experimental impact shocks. Science 276, 390–392 (1997).

    CAS  Article  Google Scholar 

  8. 8

    Fegley, B. Jr, Prinn, R. G., Hartman, H. & Watkins, G. H. Chemical effects of large impacts on the Earth's primitive atmosphere. Nature 319, 305–308 (1986).

    CAS  Article  Google Scholar 

  9. 9

    Ehrenfreund, P. & Charnley, S. B. Organic molecules in the interstellar medium, comets, and meteorites: a voyage from dark clouds to the early earth. Annu. Rev. Astron. Astrophys. 38, 427–483 (2000).

    CAS  Article  Google Scholar 

  10. 10

    Ehrenfreund, P. et al. Astrophysical and astrochemical insights into the origin of life. Rep. Prog. Phys. 65, 1427–1487 (2002).

    CAS  Article  Google Scholar 

  11. 11

    Elsila, J. E., Glavin, D. P. & Dworkin, J. P. Cometary glycine detected in samples returned by stardust. Meteorit. Planet. Sci. 44, 1323–1330 (2009).

    CAS  Article  Google Scholar 

  12. 12

    Muñoz Caro, G. M. M. et al. Amino acids from ultraviolet irradiation of interstellar ice analogues. Nature 416, 403–406 (2002).

    Article  Google Scholar 

  13. 13

    Blank, J. G., Miller, G. H., Ahrens, M. J. & Winans, R. E. Experimental shock chemistry of aqueous amino acid solutions and the cometary delivery of prebiotic compounds. Origins Life Evol. B 31, 15–51 (2001).

    CAS  Article  Google Scholar 

  14. 14

    Meech, K. J., Hainaut, O. R. & Marsdenc, B. G. Comet nucleus size distributions from HST and Keck telescopes. Icarus 170, 463–491 (2004).

    Article  Google Scholar 

  15. 15

    Robertson, D. H., Brenner, D. W. & White, C. T. Split shock wave from molecular dynamics. Phys. Rev. Lett. 67, 3132–3135 (1991).

    CAS  Article  Google Scholar 

  16. 16

    Gahagan, K. T., Moore, D. S., Funk, D. J., Rabie, R. L. & Buelow, S. J. Measurement of shock wave rise times in metal thin films. Phys. Rev. Lett. 85, 3205–3208 (2000).

    CAS  Article  Google Scholar 

  17. 17

    Kadau, K., Germann, T. C., Lomdhal, P. S. & Holian, B. L. Microscopic view of structural phase transitions induced by shock waves. Science 296, 1681–1684 (2002).

    CAS  Article  Google Scholar 

  18. 18

    Chyba, C. F., Thomas, P. J., Brookshaw, L. & Sagan, C. Cometary delivery of organic molecules to early earth. Science 249, 366–373 (1990).

    CAS  Article  Google Scholar 

  19. 19

    Pierazzo, E., Kring, D. A. & Melosh, H. J. Hydrocode simulation of the Chicxulub impact event and the production of climatically active gases. J. Geophys. Res. 103, 28607–28625 (1998).

    CAS  Article  Google Scholar 

  20. 20

    Furukawa, Y., Sekine, T., Oba, M., Kakegawa, T. & Nakazawa, H. Biomolecule formation by oceanic impacts on early Earth. Nature Geosci. 2, 62–66 (2009).

    CAS  Article  Google Scholar 

  21. 21

    Bernstein, M. P., Dworkin, J. P., Sandford, S. A., Cooper, G. W. & Allamandola, L. J. Racemic amino acids from the ultraviolet photolysis of interstellar ice analogues. Nature 416, 401–403 (2002).

    CAS  Article  Google Scholar 

  22. 22

    Huber, C. & Wächterhäuser, G. Peptides by activation of amino acids with CO on (Ni,Fe)S surfaces: implications for the origin of life. Science 281, 670–672 (1998).

    CAS  Article  Google Scholar 

  23. 23

    Gygi, F. & Galli, G. Electronic excitations and the compressibility of deuterium. Phys. Rev. B 65, 220102 (2002).

    Article  Google Scholar 

  24. 24

    Kress, J. D., Mazevet, S., Collins, L. A. & Wood, W. W. Density-functional calculation of the Hugoniot of shocked liquid nitrogen. Phys. Rev. B 63, 024203 (2000).

    Article  Google Scholar 

  25. 25

    Mundy, C. J. et al. Ultrafast transformation of graphite into diamond: an ab initio study of graphite under shock compression. J. Chem. Phys. 128, 184701 (2008).

    Article  Google Scholar 

  26. 26

    Goncharov, A. F. et al. Dynamic ionization of water under extreme conditions. Phys. Rev. Lett. 94, 125508 (2005).

    Article  Google Scholar 

  27. 27

    Schwegler, E., Sharma, M., Gygi, F. & Galli, G. Melting of ice under pressure. Proc. Natl Acad. Sci. USA 105, 14779–14783 (2008).

    CAS  Article  Google Scholar 

  28. 28

    Goldman, N. et al. Ab initio simulation of the equation of state and kinetics of shocked water. J. Chem. Phys. 130, 124517 (2009).

    Article  Google Scholar 

  29. 29

    Reed, E. J., Manaa, M. R., Fried, L. E., Glaesemann, K. R. & Joannopoulos, J. D. A transient semimetallic layer in detonating nitromethane. Nature Phys. 4, 72–76 (2008).

    CAS  Article  Google Scholar 

  30. 30

    Reed, E. J., Fried, L. E. & Joannopoulos, J. D. A method for tractable dynamical studies of single and double shock compression. Phys. Rev. Lett. 90, 235503 (2003).

    Article  Google Scholar 

  31. 31

    Reed, E. J., Fried, L. E., Henshaw, W. D. & Tarver, C. M. Simulation technique for steady shock waves in materials with analytical equations of state. Phys. Rev. E 74, 056706 (2006).

    Article  Google Scholar 

  32. 32

    Reed, E. J., Maiti, A. & Fried, L. E. Anomalous sound propagation and slow kinetics in dynamically compressed amorphous carbon. Phys. Rev. E 81, 016607 (2009).

    Article  Google Scholar 

  33. 33

    Walsh, J. M. & Rice, M. H. Dynamic compression of liquids from measurements on strong shock waves. J. Chem. Phys. 26, 815–823 (1957).

    CAS  Article  Google Scholar 

  34. 34

    Mitchell, A. C. & Nellis, W. J. Equation of state and electrical conductivity of water and ammonia shocked to the 100 GPa (1 Mbar) pressure range. J. Chem. Phys. 76, 6273–6281 (1982).

    CAS  Article  Google Scholar 

  35. 35

    Shoemaker, E. M. in The Physics and Astronomy of the Moon (ed. Kopal, Z.) 283–359 (Academic Press, 1962).

  36. 36

    Beer, E., Podolak, M. & Prialnik, D. The contribution of icy grains to the activity of comets I. Grain lifetime and distribution. Icarus 180, 473–486 (2006).

    Article  Google Scholar 

  37. 37

    Yano, K. & Horie, Y. Discrete-element modeling of shock compression of polycrystalline copper. Phys. Rev. B 59, 13672–13680 (1999).

    CAS  Article  Google Scholar 

  38. 38

    Goldman, N., Fried, L. E., Kuo, I.-F. W. & Mundy, C. J. Bonding in the superionic phase of water. Phys. Rev. Lett. 94, 217801 (2005).

    Article  Google Scholar 

  39. 39

    Goldman, N. & Fried, L. E. First principles simulation of a superionic phase of hydrogen fluoride (HF) at high pressures and temperatures. J. Chem. Phys. 125, 044501 (2006).

    Article  Google Scholar 

  40. 40

    Goldman, N. & Fried, L. E. X-ray scattering intensities of water at extreme conditions. J. Chem. Phys. 126, 134505 (2007).

    Article  Google Scholar 

  41. 41

    Geissler, P. L., Dellago, C. D., Chandler, D., Hutter, J. & Parrinello, M. Autoionization in liquid water. Science 291, 2121–2124 (2001).

    CAS  Article  Google Scholar 

  42. 42

    Wu, C., Fried, L. E., Yang, L. H., Goldman, N. & Bastea, S. Catalytic behaviour of dense hot water. Nature Chem. 1, 57–62 (2009).

    CAS  Article  Google Scholar 

  43. 43

    Bastea, S. & Fried, L. E. Exp6-polar thermodynamics of dense supercritical water. J. Chem. Phys. 128, 174502 (2008).

    Article  Google Scholar 

  44. 44

    Klamt, A. COSMO-RS: From Quantum Chemistry to Fluid Phase Dynamics and Drug Design (Elsevier, 2005).

  45. 45

    Patterson, J. E., Dreger, Z. A., Miao, M. & Gupta, Y. M. Shock wave induced decomposition of RDX: time-resolved spectroscopy. J. Phys. Chem. A 112, 7374–7382 (2008).

    CAS  Article  Google Scholar 

  46. 46

    VandeVondele, J. et al. Quickstep: fast and accurate density functional calculations using a mixed Gaussian and plane waves approach. Comp. Phys. Comm. 167, 103–128 (2005).

    CAS  Article  Google Scholar 

  47. 47

    Goedecker, S., Teter, M. & Hutter, J. Separable dual-space gaussian pseudopotentials. Phys. Rev. B 54, 1703–1710 (1996).

    CAS  Article  Google Scholar 

  48. 48

    Becke, A. D. Density-functional exchange-energy approximation with correct asymptotic behavior. Phys. Rev. A 38, 3098–3100 (1988).

    CAS  Article  Google Scholar 

  49. 49

    Lee, C., Yang, W. & Parr, R. G. Development of the Colle–Salvetti correlation-energy formula into a functional of the density. Phys. Rev. B 37, 785–789 (1988).

    CAS  Article  Google Scholar 

  50. 50

    Zel'dovitch, Y. B. & Raizer, Y. P. Physics of Shock Waves and High-Temperature Hydrodynamic Phenomena (Dover Publications, 2002).

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This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory (LLNL) under Contract DE-AC52-07NA27344. The project 06-ERD-037 was funded by the Laboratory Directed Research and Development Program at LLNL. Computations were performed at LLNL using the massively parallel computers Thunder, ATLAS, uP, UM, UV, Gauss and Prism. We acknowledge L. Krauss for help with constructing the graphics in Figs 2 and  4.

Author information




N.G. originated the central idea for this work and performed and analysed the simulations. E.J.R. is lead author for the MSST algorithm and helped write the paper. L.E.F. co-created the MSST algorithm, wrote the molecular analyser code and helped write this paper. I.W.K. helped with the initial equilibration simulations. A.M. performed the Gibbs free energy of reaction calculations.

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Correspondence to Nir Goldman or Evan J. Reed.

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The authors declare no competing financial interests.

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Goldman, N., Reed, E., Fried, L. et al. Synthesis of glycine-containing complexes in impacts of comets on early Earth. Nature Chem 2, 949–954 (2010).

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