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Impact jetting as the origin of chondrules

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Abstract

Chondrules are the millimetre-scale, previously molten, spherules found in most meteorites1. Before chondrules formed, large differentiating planetesimals had already accreted2. Volatile-rich olivine reveals that chondrules formed in extremely solid-rich environments, more like impact plumes than the solar nebula3,4,5. The unique chondrules in CB chondrites probably formed in a vapour-melt plume produced by a hypervelocity impact6 with an impact velocity greater than 10 kilometres per second. An acceptable formation model for the overwhelming majority of chondrules, however, has not been established. Here we report that impacts can produce enough chondrules during the first five million years of planetary accretion to explain their observed abundance. Building on a previous study of impact jetting7, we simulate protoplanetary impacts, finding that material is melted and ejected at high speed when the impact velocity exceeds 2.5 kilometres per second. Using a Monte Carlo accretion code, we estimate the location, timing, sizes, and velocities of chondrule-forming impacts. Ejecta size estimates8 indicate that jetted melt will form millimetre-scale droplets. Our radiative transfer models show that these droplets experience the expected cooling rates of ten to a thousand kelvin per hour9,10. An impact origin for chondrules implies that meteorites are a byproduct of planet formation rather than leftover building material.

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Figure 1: Jetting of melted material during an accretionary impact.
Figure 2: Timing and location of chondrule-forming impact.
Figure 3: The cumulative mass of chondrules created by accretionary impacts.
Figure 4: Chondrule cooling rates as a function of impactor size.

References

  1. Scott, E. R. D. Chondrites and the protoplanetary disk. Annu. Rev. Earth Planet. Sci. 35, 577–620 (2007)

    ADS  CAS  Article  Google Scholar 

  2. Kruijer, T. S. et al. Protracted core formation and rapid accretion of protoplanets. Science 344, 1150–1154 (2014)

    ADS  CAS  PubMed  Article  Google Scholar 

  3. Fedkin, A. V. & Grossman, L. Vapor saturation of sodium: key to unlocking the origin of chondrules. Geochim. Cosmochim. Acta 112, 226–250 (2013)

    ADS  CAS  Article  Google Scholar 

  4. Alexander, C. M. O. & Ebel, D. S. Questions, questions: Can the contradictions between the petrologic, isotopic, thermodynamic, and astrophysical constraints on chondrule formation be resolved? Meteorit. Planet. Sci. 47, 1157–1175 (2012)

    ADS  CAS  Article  Google Scholar 

  5. Alexander, C. M. O., Grossman, J. N., Ebel, D. S. & Ciesla, F. J. The formation conditions of chondrules and chondrites. Science 320, 1617–1619 (2008)

    ADS  CAS  PubMed  Article  Google Scholar 

  6. Krot, A. N., Amelin, Y., Cassen, P. & Meibom, A. Young chondrules in CB chondrites from a giant impact in the early Solar System. Nature 436, 989–992 (2005)

    ADS  CAS  PubMed  Article  Google Scholar 

  7. Johnson, B. C., Bowling, T. J. & Melosh, H. J. Jetting during vertical impacts of spherical projectiles. Icarus 238, 13–22 (2014)

    ADS  CAS  Article  Google Scholar 

  8. Johnson, B. C. & Melosh, H. J. Formation of melt droplets, melt fragments, and accretionary impact lapilli during a hypervelocity impact. Icarus 228, 347–363 (2014)

    ADS  Article  Google Scholar 

  9. Lofgren, G. & Russell, W. J. Dynamic crystallization of chondrule melts of porphyritic and radial pyroxene composition. Geochim. Cosmochim. Acta 50, 1715–1726 (1986)

    ADS  CAS  Article  Google Scholar 

  10. Desch, S. J., Morris, M. A., Connolly, H. C. & Boss, A. P. The importance of experiments: constraints on chondrule formation models. Meteorit. Planet. Sci. 47, 1139–1156 (2012)

    ADS  CAS  Article  Google Scholar 

  11. Collins, G. S., Melosh, H. J. & Ivanov, B. A. Modeling damage and deformation in impact simulations. Meteorit. Planet. Sci. 39, 217–231 (2004)

    ADS  CAS  Article  Google Scholar 

  12. Wünnemann, K., Collins, G. S. & Melosh, H. J. A strain-based porosity model for use in hydrocode simulations of impacts and implications for transient crater growth in porous targets. Icarus 180, 514–527 (2006)

    ADS  Article  Google Scholar 

  13. Melosh, H. J. Impact Cratering: a Geologic Process (Oxford Univ. Press, 1989)

    Google Scholar 

  14. Weiss, B. P. & Elkins-Tanton, L. T. Differentiated planetesimals and the parent bodies of chondrites. Annu. Rev. Earth Planet. Sci. 41, 529–560 (2013)

    ADS  CAS  Article  Google Scholar 

  15. Bland, P. A. et al. Volatile fractionation in the early solar system and chondrule/matrix complementarity. Proc. Natl Acad. Sci. USA 102, 13755–13760 (2005)

    ADS  CAS  PubMed  Article  Google Scholar 

  16. Asphaug, E., Jutzi, M. & Movshovitz, N. Chondrule formation during planetesimal accretion. Earth Planet. Sci. Lett. 308, 369–379 (2011)

    ADS  CAS  Article  Google Scholar 

  17. Sanders, I. S. & Scott, E. R. D. The origin of chondrules and chondrites: debris from low-velocity impacts between molten planetesimals? Meteorit. Planet. Sci. 47, 2170–2192 (2012)

    ADS  CAS  Article  Google Scholar 

  18. Taylor, G. J., Scott, E. R. D. & Keil, K. Cosmic setting for chondrule formation. In LPI Conf. on ‘Chondrules and their Origins’ 493, abstract 58, http://adsabs.harvard.edu/abs/1983chto.conf..262T (1982)

  19. Mastin, L. G. & Ghiorso, M. S. Adiabatic temperature changes of magma–gas mixtures during ascent and eruption. Contrib. Mineral. Petrol. 141, 307–321 (2001)

    ADS  CAS  Article  Google Scholar 

  20. Minton, D. A. & Levison, H. F. Planetesimal-driven migration of terrestrial planet embryos. Icarus 232, 118–132 (2014)

    ADS  Article  Google Scholar 

  21. Morbidelli, A., Bottke, W. F., Nesvorný, D. & Levison, H. F. Asteroids were born big. Icarus 204, 558–573 (2009)

    ADS  Article  Google Scholar 

  22. Connelly, J. N. et al. The absolute chronology and thermal processing of solids in the solar protoplanetary disk. Science 338, 651–655 (2012)

    ADS  CAS  PubMed  Article  Google Scholar 

  23. Hood, L. L. & Weidenschilling, S. J. The planetesimal bow shock model for chondrule formation: a more quantitative assessment of the standard (fixed Jupiter) case. Meteorit. Planet. Sci. 47, 1715–1727 (2012)

    ADS  CAS  Article  Google Scholar 

  24. Evans, N. J. I. et al. The Spitzer c2d legacy results: star-formation rates and efficiencies; evolution and lifetimes. Astrophys. J. 181 (Suppl.). 321–350 (2009)

    Article  Google Scholar 

  25. O'Brien, D. P., Morbidelli, A. & Bottke, W. F. The primordial excitation and clearing of the asteroid belt—revisited. Icarus 191, 434–452 (2007)

    ADS  Article  Google Scholar 

  26. Melosh, H. J. & Sonett, C. P. When worlds collide—jetted vapor plumes and the Moon’s origin. In LPI Conf. on ‘Origin of the Moon’ 1, 621–642, http://adsabs.harvard.edu/abs/1986ormo.conf.621M (1986)

  27. Vickery, A. M. The theory of jetting: application to the origin of tektites. Icarus 105, 441–453 (1993)

    ADS  Article  Google Scholar 

  28. Weidenschilling, S. J. Initial sizes of planetesimals and accretion of the asteroids. Icarus 214, 671–684 (2011)

    ADS  Article  Google Scholar 

  29. Hezel, D. C. & Palme, H. The conditions of chondrule formation, Part I: Closed system. Geochim. Cosmochim. Acta 71, 4092–4107 (2007)

    ADS  CAS  Article  Google Scholar 

  30. Cuzzi, J. N. & Alexander, C. M. O. Chondrule formation in particle-rich nebular regions at least hundreds of kilometres across. Nature 441, 483–485 (2006)

    ADS  CAS  PubMed  Article  Google Scholar 

  31. Benz, W., Cameron, A. & Melosh, H. J. The origin of the Moon and the single-impact hypothesis III. Icarus 81, 113–131 (1989)

    ADS  CAS  PubMed  Article  Google Scholar 

  32. Thompson, S. L. & Lauson, H. S. Improvement in the Chart D Radiation-Hydrodynamic Code. III. Revised analytic equations of state. Sandia Report SC-RR-71 0174 (1984)

  33. Grady, D. E. Local inertial effects in dynamic fragmentation. J. Appl. Phys. 53, 322 (1982)

    ADS  Article  Google Scholar 

  34. Potter, R. W. K., Collins, G. S., Kiefer, W. S., McGovern, P. J. & Kring, D. A. Constraining the size of the South Pole-Aitken basin impact. Icarus 220, 730–743 (2012)

    ADS  Article  Google Scholar 

  35. Davison, T. M., Collins, G. S. & Ciesla, F. J. Numerical modelling of heating in porous planetesimal collisions. Icarus 208, 468–481 (2010)

    ADS  Article  Google Scholar 

  36. Bowling, T. J. et al. Antipodal terrains created by the Rheasilvia basin forming impact on asteroid 4 Vesta. J. Geophys. Res. Planets (2013)

  37. Collins, G. S. & Melosh, H. J. Improvements to ANEOS for multiple phase transitions. Lunar Planet. Sci. Conf. 2664, (2014)

  38. Kraus, R. G. et al. Shock vaporization of silica and the thermodynamics of planetary impact events. J. Geophys. Res. 117, E09009 (2012)

    ADS  Google Scholar 

  39. Kurosawa, K. et al. Shock-induced silicate vaporization: the role of electrons. J. Geophys. Res. 117, E04007 (2012)

    ADS  Google Scholar 

  40. Johnson, B. C., Minton, D. A. & Melosh, H. J. The impact origin of chondrules. Lunar Planet. Sci. Conf. 1471, (2014)

  41. Bingjing, S. & Olson, G. L. Benchmark results for the non-equilibrium Marshak diffusion problem. J. Quant. Spectrosc. Radiat. Transf. 56, 337–351 (1996)

    ADS  Article  Google Scholar 

  42. Abrahamson, J. Collision rates of small particles in a vigorously turbulent fluid. Chem. Eng. Sci. 30, 1371–1379 (1975)

    CAS  Article  Google Scholar 

  43. Weidenschilling, S. J. Particles in the nebular midplane: collective effects and relative velocities. Meteorit. Planet. Sci. 45, 276–288 (2010)

    ADS  CAS  Article  Google Scholar 

  44. Ormel, C. W. & Cuzzi, J. N. Closed-form expressions for particle relative velocities induced by turbulence. Astron. Astrophys. 466, 413–420 (2007)

    ADS  MATH  Article  Google Scholar 

  45. Ciesla, F. J. Chondrule collisions in shock waves. Meteorit. Planet. Sci. 41, 1347–1359 (2006)

    ADS  CAS  Article  Google Scholar 

  46. Wünnemann, K., Collins, G. S. & Osinski, G. R. Numerical modelling of impact melt production in porous rocks. Earth Planet. Sci. Lett. 269, 530–539 (2008)

    ADS  Article  CAS  Google Scholar 

  47. Collins, G. S., Melosh, H. J. & Wünnemann, K. Improvements to the ε-α porous compaction model for simulating impacts into high-porosity solar system objects. Int. J. Impact Eng. 38, 434–439 (2011)

    Article  Google Scholar 

Download references

Acknowledgements

We thank I. Sanders for his review, which improved the manuscript. We gratefully acknowledge the developers of iSALE (http://www.isale-code.de/redmine/projects/isale), especially G. Collins, K. Wünnemann, D. Elbeshausen and B. Ivanov. This research was supported by NASA grant number PGG NNX10AU88G.

Author information

Authors and Affiliations

Authors

Contributions

While working on calculating the cooling rates of impact-produced chondrules with H.J.M., B.C.J. conceived the idea that chondrules could form by jetting during low-velocity accretionary impacts. D.A.M. produced the Monte Carlo accretion code results. B.C.J. produced the hydrocode and radiative transfer code results. All authors contributed to preparation of the manuscript and the conclusions presented in this work.

Corresponding author

Correspondence to Brandon C. Johnson.

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Competing interests

The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 Timing and velocity of chondrule-forming impact.

Chondrule-forming impacts with velocities above 2.5 km s−1 for the MMSN model (a) and the 3MMSN model (b). The points are coloured according to vimp/vesc (shown on the colour scale). Note that vimp/vesc may be less than one because vesc is considered to be the escape velocity after the target and impactor have combined to form a more massive body.

Extended Data Figure 2 Maximum size of droplets created by jetting.

The different lines represent different impact velocities, as indicated.

Extended Data Figure 3 Schematic showing the geometry of our radiative transfer models.

The horizontal axis shows radial distance from the point of impact. The vertical axis marks the thickness of the jet. We model a portion of the jet as an annulus that moves outward radially. The width of this annulus also grows with time. BC, boundary condition; h, the thickness of the jet.

Extended Data Figure 4 Temperature time history for a jet consisting of 1-mm-diameter droplets created by a 1,000-km-diameter impactor.

The different coloured curves represent different computational cells, as indicated, where cell 1 is the innermost cell, which has a reflective boundary condition on one side, and cell 400 is the outermost cell, which radiates into a background at 300 K. The thick grey curve is the mass-averaged temperature, which we use as proxy for the average temperature of material in the plume. Panel a shows the temperature as a function of time, while b shows the cooling rate as a function of time.

Extended Data Figure 5 Chondrule density and collision rates.

a, The number density of chondrules is plotted as a function of time for 100-km-diameter and 1,000-km-diameter impactors. b, Relative collision velocity plotted as a function of time. c, Rate of collisions a single chondrule experiences plotted as a function of time. d, Cumulative number of impacts a chondrule experiences plotted as a function of time.

Extended Data Table 1 iSALE input parameters

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Johnson, B., Minton, D., Melosh, H. et al. Impact jetting as the origin of chondrules. Nature 517, 339–341 (2015). https://doi.org/10.1038/nature14105

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