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Evidence for very early migration of the Solar System planets from the Patroclus–Menoetius binary Jupiter Trojan

Nature Astronomy (2018) | Download Citation


The orbital distribution of trans-Neptunian objects provides strong evidence for the radial migration of Neptune1,2. The outer planets’ orbits are thought to have become unstable during the early stages3, with Jupiter having scattering encounters with a Neptune-class planet4. As a consequence, Jupiter jumped inwards by a fraction of an au, as required from inner Solar System constraints5,6, and obtained its current orbital eccentricity. The timing of these events is often linked to the lunar Late Heavy Bombardment that ended ~700 Myr after the dispersal of the protosolar nebula (t0)7,8. Here, we show instead that planetary migration started shortly after t0. Such early migration is inferred from the survival of the Patroclus–Menoetius binary Jupiter Trojan9. The binary formed at tt010,11 within a massive planetesimal disk once located beyond Neptune12,13. The longer the binary stayed in the disk, the greater the likelihood that collisions would strip its components from one another. The simulations of its survival indicate that the disk had to have been dispersed by migrating planets within 100 Myr of t0. This constraint implies that the planetary migration is unrelated to the formation of the youngest lunar basins.

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The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

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  1. 1.

    Hahn, J. M. & Malhotra, R. Neptune’s migration into a stirred-up Kuiper belt: a detailed comparison of simulations to observations. Astron. J. 130, 2392–2414 (2005).

  2. 2.

    Levison, H. F., Morbidelli, A., Van Laerhoven, C., Gomes, R. & Tsiganis, K. Origin of the structure of the Kuiper belt during a dynamical instability in the orbits of Uranus and Neptune. Icarus 196, 258–273 (2008).

  3. 3.

    Tsiganis, K., Gomes, R., Morbidelli, A. & Levison, H. F. Origin of the orbital architecture of the giant planets of the Solar System. Nature 435, 459–461 (2005).

  4. 4.

    Nesvorný, D. & Morbidelli, A. Statistical study of the early Solar System’s instability with four, five, and six giant planets. Astron. J. 144, 117 (2012).

  5. 5.

    Agnor, C. B. & Lin, D. N. C. On the migration of Jupiter and Saturn: constraints from linear models of secular resonant coupling with the terrestrial planets. Astrophys. J. 745, 143 (2012).

  6. 6.

    Morbidelli, A., Brasser, R., Gomes, R., Levison, H. F. & Tsiganis, K. Evidence from the asteroid belt for a violent past evolution of Jupiter’s orbit. Astron. J. 140, 1391–1401 (2010).

  7. 7.

    Gomes, R., Levison, H. F., Tsiganis, K. & Morbidelli, A. Origin of the cataclysmic Late Heavy Bombardment period of the terrestrial planets. Nature 435, 466–469 (2005).

  8. 8.

    Bottke, W. F. et al. An Archaean heavy bombardment from a destabilized extension of the asteroid belt. Nature 485, 78–81 (2012).

  9. 9.

    Merline, W. J. et al. S/2001 (617) 1. Int. J. Astron. Union Circ. 7741, 2 (2001).

  10. 10.

    Goldreich, P., Lithwick, Y. & Sari, R. Formation of Kuiper-belt binaries by dynamical friction and three-body encounters. Nature 420, 643–646 (2002).

  11. 11.

    Nesvorný, D., Youdin, A. N. & Richardson, D. C. Formation of Kuiper belt binaries by gravitational collapse. Astron. J. 140, 785–793 (2010).

  12. 12.

    Morbidelli, A., Levison, H. F., Tsiganis, K. & Gomes, R. Chaotic capture of Jupiter’s Trojan asteroids in the early Solar System. Nature 435, 462–465 (2005).

  13. 13.

    Nesvorný, D., Vokrouhlický, D. & Morbidelli, A. Capture of Trojans by jumping Jupiter. Astrophys. J. 768, 45 (2013).

  14. 14.

    Emery, J. P., Marzari, F., Morbidelli, A., French, L. M. & Grav, T. in Asteroids IV 203–220 (Univ. Arizona Press, Tucson, 2015).

  15. 15.

    Fraser, W. C., Brown, M. E., Morbidelli, A., Parker, A. & Batygin, K. The absolute magnitude distribution of Kuiper belt objects. Astrophys. J. 782, 100 (2014).

  16. 16.

    Grav, T. et al. WISE/NEOWISE observations of the Jovian Trojans: preliminary results. Astrophys. J. 742, 40 (2011).

  17. 17.

    Buie, M. W. et al. Size and shape from stellar occultation observations of the double Jupiter Trojan Patroclus and Menoetius. Astron. J. 149, 113 (2015).

  18. 18.

    Parker, A. H. & Kavelaars, J. J. Destruction of binary minor planets during Neptune scattering. Astrophys. J. 722, L204–L208 (2010).

  19. 19.

    Mueller, M. et al. Eclipsing binary Trojan asteroid Patroclus: thermal inertia from Spitzer observations. Icarus 205, 505–515 (2010).

  20. 20.

    Agnor, C. B. & Hamilton, D. P. Neptune’s capture of its moon Triton in a binary-planet gravitational encounter. Nature 441, 192–194 (2006).

  21. 21.

    Marchis, F. et al. The puzzling mutual orbit of the binary Trojan asteroid (624) Hektor. Astrophys. J. 783, L37 (2014).

  22. 22.

    Sonnett, S., Mainzer, A., Grav, T., Masiero, J. & Bauer, J. Binary candidates in the Jovian Trojan and Hilda populations from NEOWISE light curves. Astrophys. J. 799, 191 (2015).

  23. 23.

    Noll, K. S., Grundy, W. M., Chiang, E. I., Margot, J.-L. & Kern, S. D. in The Solar System Beyond Neptune 345–363 (Univ. Arizona Press, Tucson, 2008).

  24. 24.

    Nesvorný, D. Evidence for slow migration of Neptune from the inclination distribution of Kuiper belt objects. Astron. J. 150, 73 (2015).

  25. 25.

    Benz, W. & Asphaug, E. Catastrophic disruptions revisited. Icarus 142, 5–20 (1999).

  26. 26.

    Wong, I. & Brown, M. E. The color-magnitude distribution of small Jupiter Trojans. Astron. J. 150, 174 (2015).

  27. 27.

    Kaib, N. A. & Chambers, J. E. The fragility of the terrestrial planets during a giant-planet instability. Mon. Not. R. Astron. Soc. 455, 3561–3569 (2016).

  28. 28.

    Nesvorný, D., Roig, F. & Bottke, W. F. Modeling the historical flux of planetary impactors. Astron. J. 153, 103 (2017).

  29. 29.

    Bottke, W. F., Levison, H. F., Nesvorný, D. & Dones, L. Can planetesimals left over from terrestrial planet formation produce the lunar Late Heavy Bombardment? Icarus 190, 203–223 (2007).

  30. 30.

    Morbidelli, A. et al. The timeline of the lunar bombardment: revisited. Icarus 305, 262–276 (2018).

  31. 31.

    Gomes, R. S., Morbidelli, A. & Levison, H. F. Planetary migration in a planetesimal disk: why did Neptune stop at 30 AU? Icarus 170, 492–507 (2004).

  32. 32.

    Levison, H. F. & Duncan, M. J. The long-term dynamical behavior of short-period comets. Icarus 108, 18–36 (1994).

  33. 33.

    Nesvorný, D., Parker, J. & Vokrouhlický, D. Bi-lobed shape of Comet 67P from a collapsed binary. Astron. J. 155, 246 (2018).

  34. 34.

    Press, W. H., Teukolsky, S. A., Vetterling, W. T. & Flannery, B. P. Numerical Recipes in FORTRAN. The Art of Scientific Computing (Cambridge Univ. Press, Cambridge, 1992).

  35. 35.

    Petit, J.-M. & Mousis, O. KBO binaries: how numerous were they? Icarus 168, 409–419 (2004).

  36. 36.

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

  37. 37.

    Nesvorný, D., Vokrouhlický, D., Bottke, W. F., Noll, K. & Levison, H. F. Observed binary fraction sets limits on the extent of collisional grinding in the Kuiper belt. Astron. J. 141, 159 (2011).

  38. 38.

    Durda, D. D. et al. Size–frequency distributions of fragments from SPH/N-body simulations of asteroid impacts: comparison with observed asteroid families. Icarus 186, 498–516 (2007).

  39. 39.

    Leinhardt, Z. M. & Stewart, S. T. Full numerical simulations of catastrophic small body collisions. Icarus 199, 542–559 (2009).

  40. 40.

    Jutzi, M., Michel, P., Benz, W. & Richardson, D. C. Fragment properties at the catastrophic disruption threshold: the effect of the parent body’s internal structure. Icarus 207, 54–65 (2010).

  41. 41.

    Levison, H. F., Morbidelli, A., Tsiganis, K., Nesvorný, D. & Gomes, R. Late orbital instabilities in the outer planets induced by interaction with a self-gravitating planetesimal disk. Astron. J. 142, 152 (2011).

  42. 42.

    Morbidelli, A. & Rickman, H. Comets as collisional fragments of a primordial planetesimal disk. Astron. Astrophys. 583, A43 (2015).

  43. 43.

    Wetherill, G. W. Collisions in the asteroid belt. J. Geophys. Res. 72, 2429 (1967).

  44. 44.

    Greenberg, R. Orbital interactions—a new geometrical formalism. Astron. J. 87, 184–195 (1982).

  45. 45.

    Davis, D. R., Durda, D. D., Marzari, F., Campo Bagatin, A. & Gil-Hutton, R. in Asteroids III 545–558 (Univ. Arizona Press, Tucson, 2002).

  46. 46.

    Dell’Oro, A. & Cellino, A. The random walk of Main Belt asteroids: orbital mobility by non-destructive collisions. Mon. Not. R. Astron. Soc. 380, 399–416 (2007).

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This work was funded by NASA’s SSERVI and Emerging Worlds programmes, and the Czech Science Foundation (grant 18-06083S). We thank A. Morbidelli for helpful suggestions.

Author information


  1. Department of Space Studies, Southwest Research Institute, Boulder, CO, USA

    • David Nesvorný
    • , David Vokrouhlický
    • , William F. Bottke
    •  & Harold F. Levison
  2. Institute of Astronomy, Charles University, Prague, Czech Republic

    • David Vokrouhlický


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D.N. had the original idea, performed the simulations and prepared the manuscript for publication. D.V. developed the binary module in the collision code and the N-body code for planetary encounters. D.V., W.F.B. and H.F.L. suggested additional tests and helped to improve the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to David Nesvorný.

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  1. Supplementary Information

    Supplementary Text, Supplementary References, Supplementary Figures 1–5

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