Water is a by product of particle space-weathering by the solar wind

Posted: January 27, 2014 by tallbloke in Astrophysics, Ocean dynamics, solar system dynamics, wind

Detection of solar wind-produced water in irradiated rims on silicate minerals
John P. Bradley et al.


Whether water is produced by solar wind (SW) radiolysis has been debated for more than four decades. In this paper, we exploit the high spatial resolution of electron microscopy and sensitivity of valence electron energy-loss spectroscopy to detect water (liquid or vapor) in vesicles within (SW-produced) space-weathered rims on interplanetary dust particle (IDP) surfaces. Water in the rims has implications for the origin of water on airless bodies like the Moon and asteroids, the delivery of water to the surfaces of terrestrial planets, and the production of water in other astrophysical environments. In particular, water and organic carbon were likely delivered simultaneously by the high flux of IDPs accreted by the early Earth and other terrestrial planets.


The solar wind (SW), composed of predominantly ∼1-keV H+ ions, produces amorphous rims up to ∼150 nm thick on the surfaces of minerals exposed in space. Silicates with amorphous rims are observed on interplanetary dust particles and on lunar and asteroid soil regolith grains. Implanted H+ may react with oxygen in the minerals to form trace amounts of hydroxyl (−OH) and/or water (H2O). Previous studies have detected hydroxyl in lunar soils, but its chemical state, physical location in the soils, and source(s) are debated. If −OH or H2O is generated in rims on silicate grains, there are important implications for the origins of water in the solar system and other astrophysical environments. By exploiting the high spatial resolution of transmission electron microscopy and valence electron energy-loss spectroscopy, we detect water sealed in vesicles within amorphous rims produced by SW irradiation of silicate mineral grains on the exterior surfaces of interplanetary dust particles. Our findings establish that water is a byproduct of SW space weathering. We conclude, on the basis of the pervasiveness of the SW and silicate materials, that the production of radiolytic SW water on airless bodies is a ubiquitous process throughout the solar system.solar wind radiolysis prebiotic watercosmic dust astrobiology aberration-corrected scanning transmission electron microscopy



↵1To whom correspondence should be addressed. E-mail: johnbrad@hawaii.edu

Author contributions: J.P.B., M.H.N., H.A.B., and M.C.M. performed research; H.A.I., J.J.G.-D., J.C., H.A.B., and M.C.M. analyzed data; and J.P.B., H.A.I., J.J.G.-D., J.C., and M.H.N. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.*Topanni A, Dukes C, Baragiola R, Bradley JP (2006) 37th Lunar Planet Sci Conf, March 13–17, 2006, League City, TX, abstr. 2056.†Daulton TL, Bernatowicz TJ, Croat TK (2012) 43rd Lunar Planet Sci Conf, March 19–23, 2012, The Woodlands, TX, abstr. 2247.

This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1320115111/-/DCSupplemental.

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  1. Bob Weber says:

    From “The Earth’s Ionosphere: Plasma Physics and Electrodynamics” page 6, Figure 1.2, a chart of daytime atmospheric composition, from http://www.sciencedirect.com/science/article/pii/B0122270908001846#gr2

    below 250km, hydrogen ion and oxygen ion density curves both show sharp reductions.

    Is this an area of our atmosphere where water is literally made from solar wind constituents?

  2. Joe Lalonde says:


    Problem is we lose more water today than what is captured.
    We have MANY worlds on the edge of our solar system totally made of ice/encapsulated in ice.
    Since the make up of ice in space is has almost the EXACT same composition…Then where did the SALT come from?

  3. tallbloke says:

    Do you know Joe, I early added a comment to the article to say no SALT was used in the production of this post. 😉

    Doesn’t salt come from the rain washing minerals into the sea?

  4. Joe Lalonde says:


    There is MASSIVE salt deposits on land and since the ocean has the close to EXACT composition as the oceans then logic would state that there was far greater amounts of water in the past.
    Also salt can burn. It could NOT possibly be from this planet that started from molten rock.

  5. Andrew says:

    Talking of salinity, can anyone explain this white spot (East Pacific, Tropical) few rivers in that area http://www7320.nrlssc.navy.mil/GLBhycom1-12/navo/globalsssnowcast.gif

  6. tallbloke says:

    High rainfall making surface less salty?

  7. craigm350 says:

    Tim Cullen
    “Perhaps the Moon’s sodium tail is responsible for the enhanced level of sodium found in sea salt”


  8. Bill says:

    Quote…”Then where did the SALT come from?”

    It came from the 150 billion humans that are alleged to have lived so far, sweating as they toil to build temples and pyramids for their leaders. We are now left with a legacy of salty oceans due to this human damage. Next theory: Global Seasoning! Taxing the salt industry to prevent Global Warming. The association between saltiness and being hot is well documented and should be a cornerstone of The New Physics of the 21st century……

  9. Brian H says:

    Another thread displaced by Lalonde idiocy. Groan.

  10. Zeke says:

    “Implanted H+ may react with oxygen in the minerals to form trace amounts of hydroxyl (−OH) and/or water (H2O).”

    This would change everything. The hydrologic cycle on earth is not a closed circuit but may have inputs from space.

    I can think of other lines of inquiry to work this out, but looking on the surfaces of rocky surfaces exposed in space is a grand start to what should be a new and wonderful branch of science.

  11. tallbloke says:

    Zeke: Yes, this is a bigger deal than it first appears. And may eventually answer Joe’s salt question. Big throughput, evaporation, residue.

  12. Zeke says:

    Abstact. The Phoenix mission investigated patterned ground and weather in the northern arctic region of Mars for 5 months starting 25 May 2008 (solar longitude between 76.5° and 148°). A shallow ice table was uncovered by the robotic arm in the center and edge of a nearby polygon at depths of 5 to 18 centimeters. In late summer, snowfall and frost blanketed the surface at night; H2O ice and vapor constantly interacted with the soil. The soil was alkaline (pH = 7.7) and contained CaCO3, aqueous minerals, and salts up to several weight percent in the indurated surface soil. Their formation likely required the presence of water.

    PS. I thought you were referring to taking each other with a huge grain of salt. (; I think that is why it is said, “Salt is good.”