Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Solar wind contributions to Earth’s oceans

Abstract

The isotopic composition of water in Earth’s oceans is challenging to recreate using a plausible mixture of known extraterrestrial sources such as asteroids—an additional isotopically light reservoir is required. The Sun’s solar wind could provide an answer to balance Earth’s water budget. We used atom probe tomography to directly observe an average ~1 mol% enrichment in water and hydroxyls in the solar-wind-irradiated rim of an olivine grain from the S-type asteroid Itokawa. We also experimentally confirm that H+ irradiation of silicate mineral surfaces produces water molecules. These results suggest that the Itokawa regolith could contain ~20 l m3 of solar-wind-derived water and that such water reservoirs are probably ubiquitous on airless worlds throughout our Galaxy. The production of this isotopically light water reservoir by solar wind implantation into fine-grained silicates may have been a particularly important process in the early Solar System, potentially providing a means to recreate Earth’s current water isotope ratios.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: SEM and TEM analyses of the space-weathered surface of Itokawa particle RA_QD02_0279.
Fig. 2: Representative APT data from Itokawa particle RA_QD02_0279 and DSCO.
Fig. 3: Graph of particle diameter versus the abundance of water generated by solar wind irradiation.
Fig. 4: Diagram of the D/H ratio that results from mixing solar-wind-irradiated fine-grained particles and chondritic water reservoirs.

Similar content being viewed by others

Data availability

All data generated or analysed during this study are either included in the Article and its Supplementary Information or are available at the following open-access data repository https://doi.org/10.5525/gla.researchdata.1164. The open access data repository also contains all source data.

References

  1. Alexander, C. M. O. D. The origin of inner Solar System water. Phil. Trans. R. Soc. 375, 20150384 (2017).

    Article  ADS  Google Scholar 

  2. Marty, B. The origins and concentrations of water, carbon, nitrogen and noble gases on Earth. Earth Planet. Sci. Lett. 313, 56–66 (2012).

    Article  ADS  Google Scholar 

  3. Meech, K. & Raymond, S. N. in Planetary Astrobiology (eds Meadows V. et al.) 325–353 (Univ. of Arizona, Tuscon, 2020).

  4. Robert, F. The origin of water on Earth. Science 293, 1056–1058 (2001).

    Article  Google Scholar 

  5. Greenwood, J. P. et al. Hydrogen isotope ratios in lunar rocks indicate delivery of cometary water to the Moon. Nat. Geosci. 4, 79–82 (2011).

    Article  ADS  Google Scholar 

  6. Hallis, L. J. et al. Evidence for primordial water in Earth’s deep mantle. Science 350, 795–797 (2015).

    Article  ADS  Google Scholar 

  7. Ikoma, M. & Genda, H. Constraints on the mass of a habitable planet with water of nebular origin. Astrophys. J. 648, 696 (2006).

    Article  ADS  Google Scholar 

  8. Morbidelli, A. et al. Fossilized condensation lines in the Solar System protoplanetary disk. Icarus 267, 368–376 (2016).

    Article  ADS  Google Scholar 

  9. Morbidelli, A. et al. Source regions and timescales for the delivery of water to the Earth. Meteor. Planet. Sci. 35, 1309–1320 (2000).

    Article  ADS  Google Scholar 

  10. Piani, L. et al. Earth’s water may have been inherited from material similar to enstatite chondrite meteorites. Science 369, 1110–1113 (2020).

    Article  ADS  Google Scholar 

  11. O’Brien, D. P., Walsh, K. J., Morbidelli, A., Raymond, S. N. & Mandell, A. M. Water delivery and giant impacts in the ‘Grand Tack’ scenario. Icarus 239, 74–84 (2014).

    Article  ADS  Google Scholar 

  12. Raymond, S. N. & Izidoro, A. The empty primordial asteroid belt. Sci. Adv. 3, e1701138 (2017).

    Article  ADS  Google Scholar 

  13. Raymond, S. N., Quinn, T. & Lunine, J. I. High-resolution simulations of the final assembly of Earth-like planets I. Terrestrial accretion and dynamics. Icarus 183, 265–282 (2006).

    Article  ADS  Google Scholar 

  14. Walsh, K. J., Morbidelli, A., Raymond, S. N., O’Brien, D. P. & Mandell, A. M. A low mass for Mars from Jupiter’s early gas-driven migration. Nature 475, 206–209 (2011).

    Article  ADS  Google Scholar 

  15. Bates, H., King, A., Donaldson Hanna, K., Bowles, N. & Russell, S. Linking mineralogy and spectroscopy of highly aqueously altered CM and CI carbonaceous chondrites in preparation for primitive asteroid sample return. Meteor. Planet. Sci. 55, 77–101 (2020).

    Article  ADS  Google Scholar 

  16. McCubbin, F. M. & Barnes, J. J. Origin and abundances of H2O in the terrestrial planets, Moon, and asteroids. Earth Planet. Sci. Lett. 526, 115771 (2019).

    Article  Google Scholar 

  17. Lécuyer, C., Gillet, P. & Robert, F. The hydrogen isotope composition of seawater and the global water cycle. Chem. Geol. 145, 249–261 (1998).

    Article  ADS  Google Scholar 

  18. Marty, B. et al. Origins of volatile elements (H, C, N, noble gases) on Earth and Mars in light of recent results from the ROSETTA cometary mission. Earth Planet. Sci. Lett. 441, 91–102 (2016).

    Article  ADS  Google Scholar 

  19. Jin, Z. & Bose, M. New clues to ancient water on Itokawa. Sci. Adv. 5, eaav8106 (2019).

    Article  ADS  Google Scholar 

  20. Genda, H. & Ikoma, M. Origin of the ocean on the Earth: early evolution of water D/H in a hydrogen-rich atmosphere. Icarus 194, 42–52 (2008).

    Article  ADS  Google Scholar 

  21. Asaduzzaman, A., Muralidharan, K. & Ganguly, J. Incorporation of water into olivine during nebular condensation: insights from density functional theory and thermodynamics, and implications for phyllosilicate formation and terrestrial water inventory. Meteor. Planet. Sci. 50, 578–589 (2015).

    Article  ADS  Google Scholar 

  22. Sasaki, S. The primary solar-type atmosphere surrounding the accreting Earth: H2O-induced high surface temperature. In LPI Conference on the Origin of the Earth (eds Newsom, H. E. & Jones, J. H.) 195–209 (SAO, NASA Astrophysics Data System, 1990).

  23. Dauphas, N. & Marty, B. Inference on the nature and the mass of Earth’s late veneer from noble metals and gases. J. Geophys. Res. Planets 107, E12, 12-1 (2002).

  24. Day, J. M., Pearson, D. G. & Taylor, L. A. Highly siderophile element constraints on accretion and differentiation of the Earth-Moon system. Science 315, 217–219 (2007).

    Article  ADS  Google Scholar 

  25. Walker, R. J. Highly siderophile elements in the Earth, Moon and Mars: update and implications for planetary accretion and differentiation. Geochemistry 69, 101–125 (2009).

    Article  Google Scholar 

  26. Huss, G., Nagashima, K., Burnett, D., Jurewicz, A. & Olinger, C. A new upper limit on the D/H ratio in the solar wind. LPI 1709 (2012).

  27. Geiss, J. & Gloeckler, G. in Primordial Nuclei and their Galactic Evolution (eds von Steiger, R. et al.) 239–250 (Springer, 1998).

  28. Lodders, K. Solar system abundances and condensation temperatures of the elements. Astrophys. J. 591, 1220 (2003).

    Article  ADS  Google Scholar 

  29. Marty, B., Chaussidon, M., Wiens, R., Jurewicz, A. & Burnett, D. A 15N-poor isotopic composition for the solar system as shown by Genesis solar wind samples. Science 332, 1533–1536 (2011).

    Article  ADS  Google Scholar 

  30. Bradley, J. P. et al. Detection of solar wind-produced water in irradiated rims on silicate minerals. Proc. Natl Acad. Sci. USA 111, 1732–1735 (2014).

    Article  ADS  Google Scholar 

  31. Ichimura, A., Zent, A., Quinn, R., Sanchez, M. & Taylor, L. Hydroxyl (OH) production on airless planetary bodies: evidence from H+/D+ ion-beam experiments. Earth Planet. Sci. Lett. 345, 90–94 (2012).

    Article  ADS  Google Scholar 

  32. Liu, Y. et al. Direct measurement of hydroxyl in the lunar regolith and the origin of lunar surface water. Nat. Geosci. 5, 779–782 (2012).

    Article  ADS  Google Scholar 

  33. Lucey, P. et al. Understanding the lunar surface and space-Moon interactions. Rev. Min. Geochem. 60, 83–219 (2006).

    Article  Google Scholar 

  34. Zhu, C. et al. Untangling the formation and liberation of water in the lunar regolith. Proc. Natl Acad. Sci. USA 116, 11165–11170 (2019).

    Article  ADS  Google Scholar 

  35. Bandfield, J. L., Poston, M. J., Klima, R. L. & Edwards, C. S. Widespread distribution of OH/H2O on the lunar surface inferred from spectral data. Nat. Geosci. 11, 173–177 (2018).

    Article  ADS  Google Scholar 

  36. Pieters, C. M. et al. Character and spatial distribution of OH/H2O on the surface of the Moon seen by M3 on Chandrayaan-1. Science 326, 568–572 (2009).

    Article  ADS  Google Scholar 

  37. Sunshine, J. M. et al. Temporal and spatial variability of lunar hydration as observed by the Deep Impact spacecraft. Science 326, 565–568 (2009).

    Article  ADS  Google Scholar 

  38. Pasek, M. & Lauretta, D. Extraterrestrial flux of potentially prebiotic C, N, and P to the early Earth. Origins Life Evol. Biosph. 38, 5–21 (2008).

    Article  ADS  Google Scholar 

  39. Canup, R. M. Simulations of a late lunar-forming impact. Icarus 168, 433–456 (2004).

    Article  ADS  Google Scholar 

  40. 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).

    Article  ADS  Google Scholar 

  41. MacGregor, M. A. et al. Constraints on planetesimal collision models in debris disks. Astrophys. J. 823, 79 (2016).

    Article  ADS  Google Scholar 

  42. Poppe, A. R. An improved model for interplanetary dust fluxes in the outer Solar System. Icarus 264, 369–386 (2016).

    Article  ADS  Google Scholar 

  43. Reddy, S. M. et al. Atom probe tomography: development and application to the geosciences. Geostand. Geoanal. Res. 44, 5–50 (2020).

    Article  Google Scholar 

  44. Nakamura, T. et al. Itokawa dust particles: a direct link between S-type asteroids and ordinary chondrites. Science 333, 1113–1116 (2011).

    Article  ADS  Google Scholar 

  45. Noguchi, T. et al. Incipient space weathering observed on the surface of Itokawa dust particles. Science 333, 1121–1125 (2011).

    Article  ADS  Google Scholar 

  46. Greer, J. et al. Atom probe tomography of space‐weathered lunar ilmenite grain surfaces. Meteor. Planet. Sci. 55, 426–440 (2020).

    Article  ADS  Google Scholar 

  47. Noguchi, T. et al. Space weathered rims found on the surfaces of the Itokawa dust particles. Meteor. Planet. Sci. 49, 188–214 (2014).

    Article  ADS  Google Scholar 

  48. Nagao, K. et al. Irradiation history of Itokawa regolith material deduced from noble gases in the Hayabusa samples. Science 333, 1128–1131 (2011).

    Article  ADS  Google Scholar 

  49. Crider, D. H. & Vondrak, R. Hydrogen migration to the lunar poles by solar wind bombardment of the Moon. Adv. Space Res. 30, 1869–1874 (2002).

    Article  ADS  Google Scholar 

  50. Keller, L. P. & McKay, D. S. The nature and origin of rims on lunar soil grains. Geochim. Cosmochim. Acta 61, 2331–2341 (1997).

    Article  ADS  Google Scholar 

  51. Demouchy, S., Jacobsen, S. D., Gaillard, F. & Stern, C. R. Rapid magma ascent recorded by water diffusion profiles in mantle olivine. Geology 34, 429–432 (2006).

    Article  ADS  Google Scholar 

  52. Nuth, J. A. III, Brearley, A. J. & Scott, E. R. in Chondrites and the Protoplanetary Disk (eds Krot, A.N. et al.) Vol. 341, 675 (Annual Reviews, 2005).

  53. Bland, P. A. et al. Why aqueous alteration in asteroids was isochemical: high porosity ≠ high permeability. Earth Planet. Sci. Lett. 287, 559–568 (2009).

    Article  ADS  Google Scholar 

  54. Rietmeijer, F. J. Size distributions in two porous chondritic micrometeorites. Earth Planet. Sci. Lett. 117, 609–617 (1993).

    Article  ADS  Google Scholar 

  55. Zolensky, M. E. et al. Mineralogy and petrology of comet 81 P/Wild 2 nucleus samples. Science 314, 1735–1739 (2006).

    Article  ADS  Google Scholar 

  56. Love, S. & Brownlee, D. A direct measurement of the terrestrial mass accretion rate of cosmic dust. Science 262, 550–553 (1993).

    Article  ADS  Google Scholar 

  57. Anders, E. Pre-biotic organic matter from comets and asteroids. Nature 342, 255–257 (1989).

    Article  ADS  Google Scholar 

  58. Flynn, G., Keller, L., Jacobsen, C. & Wirick, S. An assessment of the amount and types of organic matter contributed to the Earth by interplanetary dust. Adv. Space Res. 33, 57–66 (2004).

    Article  ADS  Google Scholar 

  59. Ishii, H. A. et al. Multiple generations of grain aggregation in different environments preceded solar system body formation. Proc. Natl Acad. Sci. USA 115, 6608–6613 (2018).

    Article  ADS  Google Scholar 

  60. Vican, L. & Schneider, A. The evolution of dusty Debris disks around solar type stars. Astrophys. J. 780, 154 (2013).

    Article  ADS  Google Scholar 

  61. Wyatt, M. The insignificance of PR drag in detectable extrasolar planetesimal belts. Astron. Astrophys. 433, 1007–1012 (2005).

    Article  ADS  Google Scholar 

  62. Nesvorný, D. et al. Cometary origin of the zodiacal cloud and carbonaceous micrometeorites. Implications for hot debris disks. Astrophys. J. 713, 816 (2010).

    Article  ADS  Google Scholar 

  63. Ayres, T. R. Evolution of the solar ionizing flux. J. Geophys. Res. Planets 102, 1641–1651 (1997).

    Article  ADS  Google Scholar 

  64. Kass, D. & Yung, Y. L. Loss of atmosphere from Mars due to solar wind-induced sputtering. Science 268, 697–699 (1995).

    Article  ADS  Google Scholar 

  65. Suess, H., Wänke, H. & Wlotzka, F. On the origin of gas-rich meteorites. Geochim. Cosmochim. Acta 28, 595–607 (1964).

    Article  ADS  Google Scholar 

  66. Krietsch, D. et al. Noble gases in CM carbonaceous chondrites: effect of parent body aqueous and thermal alteration and cosmic ray exposure ages. Geochim. Cosmochim. Acta. 310, 240–280 (2021).

    Article  ADS  Google Scholar 

  67. Walsh, K. J. Rubble pile asteroids. Annu. Rev. Astron. Astrophys. 56, 593–624 (2018).

    Article  ADS  Google Scholar 

  68. Dukes, C., Baragiola, R. & McFadden, L. Surface modification of olivine by H+ and He+ bombardment. J. Geophys. Res. Planets 104, 1865–1872 (1999).

    Article  ADS  Google Scholar 

  69. Loeffler, M., Dukes, C. & Baragiola, R. Irradiation of olivine by 4 keV He+: Simulation of space weathering by the solar wind. J. Geophys. Res. Planets 114, E3 (2009).

    Article  Google Scholar 

  70. Thompson, K. et al. In situ site-specific specimen preparation for atom probe tomography. Ultramicroscopy 107, 131–139 (2007).

    Article  Google Scholar 

  71. MacArthur, K. E. et al. Optimizing experimental conditions for accurate quantitative energy-dispersive X-ray analysis of interfaces at the atomic scale.Microscopy Microanalysis 27, 1–15 (2021).

    Google Scholar 

  72. Larson, D. J., Prosa, T., Ulfig, R. M., Geiser, B. P. & Kelly, T. F. Local Electrode Atom Probe Tomography Vol. 2 (Springer Science, 2013).

  73. Lewis, J. B., Isheim, D., Floss, C. & Seidman, D. N. C12/C13-ratio determination in nanodiamonds by atom-probe tomography. Ultramicroscopy 159, 248–254 (2015).

    Article  Google Scholar 

  74. Meisenkothen, F., Steel, E. B., Prosa, T. J., Henry, K. T. & Kolli, R. P. Effects of detector dead-time on quantitative analyses involving boron and multi-hit detection events in atom probe tomography. Ultramicroscopy 159, 101–111 (2015).

    Article  Google Scholar 

  75. Stephan, T., Heck, P. R., Isheim, D. & Lewis, J. B. Correction of dead time effects in laser-induced desorption time-of-flight mass spectrometry: applications in atom probe tomography. Int. J. Mass Spectrom. 379, 46–51 (2015).

    Article  Google Scholar 

  76. Kolli, R. P. Controlling residual hydrogen gas in mass spectra during pulsed laser atom probe tomography. Adv. Struct. Chem. Imag. 3, 1–10 (2017).

    Article  Google Scholar 

  77. Alexander, C. M. D., McKeegan, K. D. & Altwegg, K. Water reservoirs in small planetary bodies: meteorites, asteroids, and comets. Space Sci. Rev. 214, 1–47 (2018).

    Article  Google Scholar 

  78. Garenne, A. et al. The abundance and stability of “water” in type 1 and 2 carbonaceous chondrites (CI, CM and CR). Geochim. Cosmochim. Acta 137, 93–112 (2014).

    Article  ADS  Google Scholar 

  79. LPI. The Meteoritical Bulletin (The Meteoritical Society, 2020); https://www.lpi.usra.edu/meteor/metbull.php

  80. Szurgot M. Mean atomic weight of Earth, Moon, Venus, Mercury and Mars. Effect of mass of cores and density of planets. In 46th Lunar and Planetary Science Conference 1536 (USRA, 2015); https://www.hou.usra.edu/meetings/lpsc2015/pdf/1536.pdf

  81. Anderson, D. L. & Kovach, R. L. The composition of the terrestrial planets. Earth Planet. Sci. Lett. 3, 19–24 (1967).

    Article  ADS  Google Scholar 

  82. Vacher, L. G. et al. Hydrogen in chondrites: influence of parent body alteration and atmospheric contamination on primordial components. Geochim. Cosmochim. Acta 281, 53–66 (2020).

    Article  ADS  Google Scholar 

  83. Greenberg, J. M. Making a comet nucleus. Astron. Astrophys. 330, 375–380 (1998).

    ADS  Google Scholar 

  84. Peslier, A. H., Schönbächler, M., Busemann, H. & Karato, S.-I. Water in the Earth’s interior: distribution and origin. Space Sci. Rev. 212, 743–810 (2017).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

The Hayabusa-returned sample RA-QD02-0279 was allocated to L.D. by the Planetary Material Sample Curation Facility of JAXA through the 5th International Announcement of Opportunity held in 2017. We would like to thank M. Suttle for the preparation and loan of the mounting rod, R. Ickert for providing access to the clean lab facility at the Scottish Universities Environmental Research Centre to mount the Itokawa particles and R. Mahajan for providing suitably fine-grained basaltic fragments to practice on. L.D. would also like to thank NASA JSC and the Lunar and Planetary Institute for the training received at the 4th training in extraterrestrial sample handling course. This work was funded by the UK STFC consortium grant numbers ST/T002328/1 awarded to M.R.L. and L.D. and ST/N000846/1 awarded to M.R.L. This work was also funded by a UAE seed grant awarded to M.R.L., as well as a SAGES small grant awarded to L.D. H.I. and J.P.B. were partially supported by the NASA Laboratory Analysis of Returned Samples (LARS) Program (grant number 80NSSC18K0936). This work was partially supported through the INL Laboratory Directed Research & Development (LDRD) Program under DOE Idaho Operations Office contract number DE-AC07-05ID145142, which supported J.A.A. D.F. is supported by an Australian Research Council Discovery Early Career Reseacher Award (ARC DECRA) number DE190101307. This work was conducted within the Geoscience Atom Probe Facility at Curtin University, which was developed through funding from the Science and Industry Endowment Fund (grant number SIEF RI13-01) awarded to S.M.R. This work utilized the Tescan MIRA3 FE-SEM at the John de Laeter Centre, Curtin University, which was obtained via funding from the Australian Research Council LIEF program (grant number ARC LE130100053). We acknowledge the use of Curtin University’s Microscopy and Microanalysis Facility, whose instrumentation has been partially funded by the University, State and Commonwealth Governments. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the US DOE Office of Science. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the US DOE’s National Nuclear Security Administration under contract number DE-NA-0003525. The views expressed in the article do not necessarily represent the views of the US DOE or the United States Government.

Author information

Authors and Affiliations

Authors

Contributions

L.D. conceived the project with input from M.R.L. Itokawa sample handling and mounting was conducted by M.A.C. and L.D. Itokawa SEM analysis was conducted by T.S., M.A.C. and L.D. H.A.I. and J.P.B. prepared the polished SC olivine on Ta for D2+ irradiation. J.A.A. arranged and advised on instrumentation for D2+ irradiation. K.H. and A.M. performed D2+ irradiations. L.P.K., R.C. and M.S.T. prepared the polished SC olivine for He+ irradiation and C.A.D. and M.J.L. conducted the irradiation. L.D. and S.M.R. prepared the polished SC olivine and conducted the laboratory exposure. Cr coating was undertaken by W.D.A.R., D.F. and L.D. FIB preparations for TEM and APT were undertaken by L.D., D.F. and W.D.A.R. TEM work was conducted by Z.Q., L.D. and W.D.A.R. APT analysis was undertaken by D.W.S., D.F. and L.D. The results were interpreted by L.D., P.A.B., L.V.F., M.R.L., L.J.H., N.E.T., F.J., D.W.S., D.F. and E.C. L.D., H.I. and W.D.A.R. wrote the methods. L.D. wrote the paper with input from all co-authors.

Corresponding author

Correspondence to Luke Daly.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Astronomy thanks Sean Raymond and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Back scatter electron (BSE) and in-beam secondary electron (IbSE) images of the front face of Itokawa particle RA-QD02-0279 and resulting APT specimens.

a, BSE image of the front face of Itokawa particle RA-QD02-0279 after Cr coating. b, BSE image of the front face of Itokawa particle RA-QD02-0279 after Ion beam Pt deposition in preparation for sample extraction for APT. The red circles indicate where the APT lift outs were extracted from the wedge. C) IbSE (left) and BSE (right) image of needle (D) half way through annular milling. The Pt protective layer is visible as well as the Cr layer. Annular milling was continued until the Pt was removed but leaving the Cr cap. DH) IbSE (left) and BSE images (right) of each APT needle the Cr cap is visible at the apex of each tip in the BSE images as well as the Pt weld at the base.

Extended Data Fig. 2 Back scatter electron (BSE) and in-beam secondary electron (IbSE) images of the back face of Itokawa particle RA-QD02-0279 and resulting APT specimens.

a, BSE image of the back face of Itokawa particle RA-QD02-0279 after Cr coating. b, BSE image of the back face of Itokawa particle RA-QD02-0279 after Ion beam Pt deposition in preparation for sample extraction for APT. The red circles indicate where the APT lift outs were extracted from the wedge. c, BSE image of the back face of Itokawa particle RA-QD02-0279 after FIB lift out. DH) IbSE (left) and BSE images (right) of each APT needle the Cr cap is visible at the apex of each tip in the BSE images as well as the Pt weld at the base.

Extended Data Fig. 3 APT data from Itoakwa particle RA_QD02_0279.

The APT needles extracted from the front face of Itokawa particle RA_QD02_0279 shown in Extended Data Fig. 1E (AC) and Extended Data Fig. 1G (DF) and from the back face shown in Extended Data Fig. 2F (GI) and Extended Data Fig. 2H (JL). All data extend from the Cr protective layer (grey spheres) through RA_QD02_0279’s space weathered surface into unweathered olivine. (A, D, G, and J) APT measurement of the 3D distribution of Cr (grey spheres) and OH (teal spheres). (B, E, H, and K) APT measurement of the 3D distribution of Cr (grey spheres) and H2O (blue spheres) ions. (C, F, I, and L) Concentration of ions in atomic percent (at. %) with depth across the Cr capping layer (Cr, grey shaded region) space weathered rim (SW, blue shaded region) and the non-space weathered olivine (Ol, brown shaded region) revealing variations in the abundances of Cr (grey line), H (yellow line), OH (green line) and H2O (blue line) ions. Line widths have been adjusted to represent the 1 sigma uncertainty and depth profiles are absolute abundances not relative concentrations (Supplementary Data 1). The boundary between the Cr and SW layer is marked by a vertical dashed red line and the boundary between the SW and Ol layer is marked by a vertical black dashed line.

Extended Data Fig. 4 Representative full APT mass to charge state spectra and localized mass to charge state spectra highlighting the oxygen series mass to charge peaks.

Mass to charge state (Atomic mass/charge (u/Q)) spectra showing the histogram of the number of ion counts detected at each u/Q step. For each the mass-to charge state ratio spectra the detected ions were produced from regions of interest within: A) the sputter coated Cr layer from Extended Data Fig. 3J-L, B) the bulk olivine of Itokawa from Extended Data Fig. 3J-L, C) the solar wind irradiated rim of Itokawa olivine from Extended Data Fig. 3J-L, D) D-irradiated rim from Extended Data Figure 8H-N. (AD) show the entire mass to charge state spectra from 0-150 u/Q. (E-H) show the APT mass to charge state between 16-21 u/Q that contains the Oxygen series peaks.

Extended Data Fig. 5 The effect that changing the diameter of the cylindrical region of interest has on the sputter coated Cr and olivine interface and on counting statistics under the peak.

a, The 42 nm cylindrical region of interest used to produce the concentration profiles from the APT dataset Itokawa3 Extended Data Fig. 3J-L. b, A 3 nm cylindrical region of interest from the APT dataset Itokawa3. c, Corresponding concentration profiles in atomic percent (at. %) for Cr (black line) and H (red line) from the 42 nm region of interest and sum Cr (grey line) and H (yellow line; including molecular ions) concentration profiles from the 3 nm wide cylinder. We note that the Cr-olivine interface is sharper in the 3 nm wide cylinder but it comes at the expense of the counting statistical uncertainty of the measurement. Line widths have been adjusted to represent the 1 sigma uncertainty and depth profiles are absolute abundances not relative concentrations.

Extended Data Fig. 6 Diagram of the D/H ratio that results from mixing solar wind irradiated <10 µm fine grained particles and chondritic water reservoirs.

The D/H ratio plot is generated by mixing water reservoirs of carbonaceous chondrite (CR[green volume], CI [blue volume], CM [orange volume], Cav [red volume, the average of CR,CI and CMs D/H = 0.000173[1,16]]; water abundance = 2-16 molecular % per atom[9]]), ordinary chondrite (purple volume, OC)19 and enstatite chondrite (brown volume, EC)10 material, and small space weathered particles, where only particles <10 µm that make up ~10 % of present day fine grained extraterrestrial dust are considered (D/H = 0.0000002[24] water abundance = 0.1-1.6 molecular % per atom that can reproduce the SMOW and Bulk Silicate Earth (BSE) D/H ratio1,17 (horizontal black dashed lines, Supplementary Data 3). The upper and lower bounds of each field represent the upper and lower limits of the water content within the chondrites and solar wind irradiated particles. The relative mass contributions that span BSE and SMOW D/H ratios indicates the range of potential mixtures of theses extraterrestrial water reservoirs that could generate the present-day D/H of Earth’s oceans.

Extended Data Fig. 7 Operating conditions of the geoscience atom probe (R80).

The run number for each sample and sample label are given.

Extended Data Fig. 8 APT data from DSCO and PSCO standards.

DSCO APT data sets (A-U) initially ran through the Cr protective layer (grey spheres) through DSCO’s D-irradiated surface into unweathered olivine. (A, H, and O) APT measurements of the 3D distribution of Cr (grey spheres) and D (purple spheres) ions. (B, I, and P) APT measurements of the 3D distribution of Cr (grey spheres) and D2 (orange spheres) ions. (C, J, and Q) APT measurements of the 3D distribution of Cr (grey spheres) and H (yellow spheres) ions. (D, K, and R) APT measurements of the 3D distribution of Cr (grey spheres) and DO (green spheres) ions. (E, L, and S) APT measurement of the 3D distribution of Cr (grey spheres) and D2O (turquoise spheres) ions. (F, M, and T) APT measurements of the 3D distribution of Cr (grey spheres) and OH (teal spheres) ions. (G, N, and U) Concentration of ions in atomic percent (at. %) with depth across the Cr capping layer (Cr, grey shaded region), Deuterium irradiated rim (DI, blue shaded region) and the non-Deuterium irradiated olivine (Ol, brown shaded region) revealing the variation in the abundance of Cr (grey line), D (purple line), D2 (orange line), DO (red line), D2O (blue line), H (yellow line), and OH (green line) ions. Line widths have been adjusted to represent the 1 sigma uncertainty and depth profiles are absolute abundances not relative concentrations (Supplementary Data 1). The boundary between the Cr and DI layer is marked by a vertical dashed red line and the boundary between the DI and Ol layer is marked by a vertical black dashed line. PSCO APT (VX) data initially ran through the Cr protective layer (grey spheres) into unweathered olivine. (V) APT measurements of the 3D distribution of Cr (grey spheres) and OH (teal spheres) ions. W) APT measurements of the 3D distribution of Cr (grey spheres) and H2O (blue spheres) ions. X) Concentration of ions in at. % with depth across the Cr capping layer (Cr, grey shaded region), into the olivine (Ol, brown shaded region) revealing the variation in the abundance of Cr (grey line), OH (green line) and H2O (blue line) ions. Line widths have been adjusted to represent the 1 sigma uncertainty and depth profiles are absolute abundances not relative concentrations (Supplementary Data 1). The boundary between the Cr and Ol layer is marked by a vertical dashed red and black line.

Supplementary information

Supplementary Information

Captions for Supplementary Data 1–11.

Supplementary Data 1

APT water profiles through Itokawa PSCO and DSCO data. Cylindrical region-of-interest (ROI) z profiles through APT data sets of Itokawa, PSCO and DSCO datasets used to generate Fig. 2 and Extended Data Figs. 4 and 8. ROI cylinder of Itokawa 2208 of 130 nm diameter, ROI cylinder Itokawa 2210 diameter 62 m, ROI cylinder Itokawa 02312 diameter 43 nm, ROI cylinder Itokawa 02329 diameter 50 nm, ROI cylinder of D+ irradiated 03028 diameter 70 nm, ROI cylinder of D+ irradiated 03029 diameter 85 nm, ROI cylinder of D+ irradiated 03030 diameter 71 nm ROI cylinder of SCO 02334 diameter 67 nm. All have a 2 nm bin width for concentration profiles.

41550_2021_1487_MOESM3_ESM.xlsx

Supplementary Data 2 Grain-size dependence on the abundance of solar-wind-derived water. Determination of the average total water content of various sized olivine grains with typical space-weathering rim thicknesses used to generate Fig. 3.

41550_2021_1487_MOESM4_ESM.xlsx

Supplementary Data S3 D/H bulk isotope ratio calculations for the Earth. Calculations are for the incorporation of varying amounts of water from carbonaceous chondrites, enstatite chondrites, ordinary chondrites and solar wind impinging on silicate surfaces, accounting for the water variable water abundance in each component used to generate Fig 4 and Extended Data Fig. 6.

Source data

Source Data Fig. 1

Unprocessed images.

Source Data Fig. 2

Excel spreadsheet and unprocessed images.

Source Data Fig. 3

Excel spreadsheet.

Source Data Fig. 4

Excel spreadsheet.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Daly, L., Lee, M.R., Hallis, L.J. et al. Solar wind contributions to Earth’s oceans. Nat Astron 5, 1275–1285 (2021). https://doi.org/10.1038/s41550-021-01487-w

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41550-021-01487-w

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing