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Reorientation of Sputnik Planitia implies a subsurface ocean on Pluto


The deep nitrogen-covered basin on Pluto, informally named Sputnik Planitia, is located very close to the longitude of Pluto’s tidal axis1 and may be an impact feature2, by analogy with other large basins in the Solar System3,4. Reorientation5,6,7 of Sputnik Planitia arising from tidal and rotational torques can explain the basin’s present-day location, but requires the feature to be a positive gravity anomaly7, despite its negative topography. Here we argue that if Sputnik Planitia did indeed form as a result of an impact and if Pluto possesses a subsurface ocean, the required positive gravity anomaly would naturally result because of shell thinning and ocean uplift, followed by later modest nitrogen deposition. Without a subsurface ocean, a positive gravity anomaly requires an implausibly thick nitrogen layer (exceeding 40 kilometres). To prolong the lifetime of such a subsurface ocean to the present day8 and to maintain ocean uplift, a rigid, conductive water-ice shell is required. Because nitrogen deposition is latitude-dependent9, nitrogen loading and reorientation may have exhibited complex feedbacks7.

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Figure 1: Sputnik Planitia topography and reorientation.
Figure 2: Load thicknesses L and resulting gravity anomalies Δg for present-day Sputnik Planitia topography.
Figure 3: Basal shell temperature required to maintain a thinned shell for 4 billion years.


  1. Moore, J. M. et al. The geology of Pluto and Charon through the eyes of New Horizons. Science 351, 1284–1293 (2016)

    Article  ADS  CAS  Google Scholar 

  2. Schenk, P.M. et al. A large impact origin for Sputnik Planum and surrounding terrains, Pluto? Div. Planet. Sci. Meet. 47, abstr. 200.06 (2015)

    Google Scholar 

  3. Searls, M. L. et al. Utopia and Hellas basins, Mars: twins separated at birth. J. Geophys. Res. 111, E08005 (2006)

    ADS  Google Scholar 

  4. Zuber, M. T. et al. Topography of the northern hemisphere of Mercury from MESSENGER laser altimetry. Science 336, 217–220 (2012)

    Article  ADS  CAS  Google Scholar 

  5. Rubincam, D. P. Polar wander on Triton and Pluto due to volatile migration. Icarus 163, 469–478 (2003)

    Article  ADS  Google Scholar 

  6. Nimmo, F. & Matsuyama, I. Reorientation of icy satellites by impact basins. Geophys. Res. Lett. 34, L19203 (2007)

    Article  ADS  Google Scholar 

  7. Keane, J. T., Matsuyama, I., Kamata, S. & Steckloff, J. K. Reorientation and faulting of Pluto due to volatile loading within Sputnik Planitia. Nature (2016)

  8. Robuchon, G. & Nimmo, F. Thermal evolution of Pluto and implications for surface tectonics and a subsurface ocean. Icarus 216, 426–439 (2011)

    Article  ADS  Google Scholar 

  9. Binzel, R. P. et al. Climate zones on Pluto and Charon. Icarus (2016)

  10. McKinnon, W. B. et al. Convection in a volatile nitrogen-ice-rich layer drives Pluto’s geological and atmospheric vigour. Nature 534, 82–85 (2016)

    Article  ADS  CAS  Google Scholar 

  11. Trowbridge, A. J. et al. Vigorous convection as the explanation for Pluto’s polygonal terrain. Nature 534, 79–81 (2016)

    Article  ADS  CAS  Google Scholar 

  12. White, O. L., Schenk, P. M. & Dombard, A. J. Impact basin relaxation on Rhea and Iapetus and relation to past heat flow. Icarus 223, 699–709 (2013)

    Article  ADS  Google Scholar 

  13. Bray, V. J. & Schenk, P. M. Pristine impact crater morphology on Pluto—expectations for New Horizons. Icarus 246, 156–164 (2015)

    Article  ADS  Google Scholar 

  14. Johnson, B. C., Bowling, T. J., Trowbridge, A. J. & Freed, A. M. Formation of the Sputnik Planum basin and the thickness of Pluto’s subsurface ocean. Geophys. Res. Lett. 43, 10068–10077 (2016)

    Article  ADS  Google Scholar 

  15. Muller, P. M. & Sjogren, W. L. Mascons – lunar mass concentrations. Science 161, 680–684 (1968)

    Article  ADS  CAS  Google Scholar 

  16. Melosh, H. J. et al. The origin of lunar mascon basins. Science 340, 1552–1555 (2013)

    Article  ADS  CAS  Google Scholar 

  17. Wieczorek, M. A. & Phillips, R. J. Lunar multiring basins and the cratering process. Icarus 139, 246–259 (1999)

    Article  ADS  Google Scholar 

  18. Kamata, S. & Nimmo, F. Impact basin relaxation as a probe for the thermal history of Pluto. J. Geophys. Res. 119, 2272–2289 (2014)

    Article  CAS  Google Scholar 

  19. Nimmo, F. Non-Newtonian topographic relaxation on Europa. Icarus 168, 205–208 (2004)

    Article  ADS  CAS  Google Scholar 

  20. McKinnon, W. B., Simonelli, D. P. & Schubert, G. in Pluto and Charon (eds Stern, S. A. & Tholen, D. J. ) 295–346 (Univ. Arizona Press, 1997)

  21. Grundy, W. M. et al. Surface compositions across Pluto and Charon. Science 351, aad9189 (2016)

  22. Hammond, N. P., Barr, A. C. & Parmentier, E. M. Recent tectonic activity on Pluto driven by phase changes in the ice shell. Geophys. Res. Lett. 43, 6775–6782 (2016)

    Article  ADS  Google Scholar 

  23. Scott, T. A. Solid and liquid nitrogen. Phys. Rep. 27, 89–157 (1976)

    Article  ADS  Google Scholar 

  24. Rubin, M. E., Desch, S. J. & Neveu, M. The effect of Rayleigh-Taylor instabilities on the thickness of undifferentiated crust on Kuiper Belt Objects. Icarus 236, 122–135 (2014)

    Article  ADS  Google Scholar 

  25. Milbury, C. et al. Preimpact porosity controls the gravity signature of lunar craters. Geophys. Res. Lett. 42, 9711–9716 (2015)

    Article  ADS  Google Scholar 

  26. Hamilton, D. P. et al. The rapid formation of Sputnik Planitia early in Pluto’s history. Nature (2016)

  27. Matsuyama, I. & Nimmo, F. Rotational stability of tidally deformed planetary bodies. J. Geophys. Res. 112, E11003 (2007)

    Article  ADS  Google Scholar 

  28. Manga, M. & Wang, C.-Y. Pressurized oceans and the eruption of liquid water on Europa and Enceladus. Geophys. Res. Lett. 34, L07202 (2007)

    Article  ADS  Google Scholar 

  29. Brown, M. E. The compositions of Kuiper Belt Objects. Annu. Rev. Earth Planet. Sci. 40, 467–494 (2012)

    Article  ADS  CAS  Google Scholar 

  30. Turcotte, D. L. et al. Role of membrane stresses in the support of planetary topography. J. Geophys. Res. 86, 3951–3959 (1981)

    Article  ADS  Google Scholar 

  31. Nimmo, F. et al. Mean radius and shape of Pluto and Charon from New Horizons images. Icarus (2016)

  32. Kargel, J. S. Ammonia water volcanism on icy satellites—phase relations at 1-atmosphere. Icarus 100, 556–574 (1992)

    Article  ADS  CAS  Google Scholar 

  33. Comer, R. P., Solomon, S. C. & Head, J. W. Mars—thickness of the lithosphere from the tectonic response to volcanic loads. Rev. Geophys. 23, 61–92 (1985)

    Article  ADS  Google Scholar 

  34. Willemann, R. J. Reorientation of planets with elastic lithospheres. Icarus 60, 701–709 (1984)

    Article  ADS  Google Scholar 

  35. Moore, W. B. & Schubert, G. The tidal response of Europa. Icarus 147, 317–319 (2000)

    Article  ADS  CAS  Google Scholar 

  36. Soderblom, J. M. et al. The fractured Moon: production and saturation of porosity in the lunar highlands from impact cratering. Geophys. Res. Lett. 42, 6939–6944 (2015)

    Article  ADS  Google Scholar 

  37. Petrenko, V. F. & Whitworth, R. W. Physics of Ice (Clarendon Press, 1999)

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New Horizons was built and operated by the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, USA, for NASA. We thank the many engineers, flight controllers and others who have contributed to the success of the New Horizons mission and NASA’s Deep Space Network for a decade of excellent support to New Horizons. We thank B. Johnson for discussions on impact physics and J. Conrad for cryovolcanism calculations.

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Authors and Affiliations




D.P.H. originated the reorientation hypothesis. F.N. developed the subsurface ocean scenario and carried out the bulk of the calculations. C.J.B. calculated the effect of realistic basin geometries and ejecta blanket. P.M.S. and R.A.B. provided the stereo topography. All authors read or commented on the manuscript.

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Correspondence to F. Nimmo.

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The authors declare no competing financial interests.

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Nature thanks G. Collins and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Extended data figures and tables

Extended Data Figure 1 Schematic of the way in which the gravity anomaly is affected by an uplifted ocean and the thickness of the nitrogen layer.

ac, Either a nitrogen layer more than 40 km thick (b) or an uplifted ocean (c) could result in the present-day positive gravity anomaly at Sputnik Planitia; if neither is present, then a negative gravity anomaly results (a). The peak gravity anomaly is calculated using the flat-plate formula 2πGΔρh for each layer, where h represents the thickness, Δρ is the lateral density contrast and the densities of H2O ice, water and N2 ice are 0.92 g cm−3, 1.0 g cm−3 and 1.0 g cm−3 (ref. 23), respectively. In c, the gravitational contribution of the ocean is reduced as a result of upwards attenuation assuming a shell thickness of 150 km (see Methods). The structure in c is similar to the inferred structure of lunar mascon basins, which also show positive gravity anomalies (refs 15, 16).

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Nimmo, F., Hamilton, D., McKinnon, W. et al. Reorientation of Sputnik Planitia implies a subsurface ocean on Pluto. Nature 540, 94–96 (2016).

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