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Sulfur abundance of asteroid 25143 Itokawa observed by X-ray fluorescence spectrometer onboard Hayabusa

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Abstract

The Japanese Hayabusa spacecraft successfully carried out in situ observations of S-class asteroid 25143 Itokawa, including the surface major elemental analysis with the X-ray fluorescence spectrometer (XRSHayabusa). Our previous results for the X-ray experiments (Okada et al., 2006a) indicated that major elemental ratios of Mg/Si and Al/Si on the surface of Itokawa resemble ordinary LL- or L-chondrites more than any other meteorite analogues. In the NEAR Shoemaker observations of S-class asteroid 433 Eros, the results of X-ray fluorescence observations indicated the depletion of sulfur, probably reflecting impact-induced volatilization, photoor ion-induced sputtering at the surface, or the loss of FeS-rich materials due to partial melting. Here, we determined the elemental abundance of sulfur (S) on the surface of Itokawa, in addition to that of Mg, Al, and Si, and its regional variation using XRS-Hayabusa observations. In particular, we carefully corrected the fluctuation of solar X-rays, variation of surface geometry, and sensor response function in this analysis, and thus we believe that the results are more accurate than those of our previous report. In this study, the upper and lower limits for Mg/Si, Al/Si, and S/Si overlap those of meteorite analogues for ordinary chondrites or primitive achondrites. In terms of the major elemental composition, Itokawa is best classified as a ordinary chondrite or a primitive achondrite. Our models do not include the mineral mixing effects. With the effects, the abundance of sulfur is expected to be 30% lower than our results. Hence, we conclude that the abundance of sulfur on the surface of Itokawa is almost equal to or even lower than the average abundance in ordinary chondrites. Although the abundances for Mg and Si are globally homogeneous, best-fit or upper limits of mass fraction for Al and S vary in local areas. There is a negative correlation (−0.92) for Al/Si vs. S/Si in ten facets. In particular, the area with the lowest sulfur, accompanied with enriched aluminum, is found in Arcoona, close to a cratered area. Therefore, aluminum enrichment and sulfur depletion features may support events of partial melting on the parent body of Itokawa or aluminum-rich material impacts on the surface of Itokawa. In some areas, Itokawa has a brighter geometric albedo and color variation. Little altered, fresh material may be exposed in these portions of the surface. The sulfur abundance on the surface appears to vary between little and highly altered areas by space weathering. Thus, the sulfur regional variation in our result may reflect the heterogeneity of a surface altered by space weathering.

References

  1. Abe, M., Y. Takagi, K. Kitazato, S. Abe, T. Hiroi, F. Vilas, B. E. Clark, P. A. Abell, S. M. Lederer, K. S. Jarvis, T. Nimura, Y. Ueda, and A. Fujiwara, Near-Infrared Spectral Results of Asteroid Itokawa from the Hayabusa Spacecraft, Science, 312, 1334–1338, 2006.

  2. Abell, P. A., F. Vilas, K. S. Jarvis, M. J. Gaffey, and M. S. Kelley, Mineralogical Composition of (25143) Itokawa 1998 SF36 from Visible and Near-Infrared Reflectance Spectroscopy: Evidence for Partial Melting, LPI, 37, 1513A, 2006.

  3. Akagawa, K., Master thesis of The University of Tokyo, 2003 (in Japanese).

  4. Anders, E. and N. Grevesse, Abundances of the elements—Meteoritic and solar, Geochim. Cosmochim. Acta, 53, 197–214, 1989.

  5. Arai, T., Master thesis of Tokyo Institute of Technology, 2003.

  6. Arnaud, K., B. Dorman, and C. Gordon, Xspec An X-ray Spectral Fitting Package User’s Guide for version 12.2, HEASARC, Exploration of the Universe Division, NASA/GSFC, 2005.

  7. Bearden, J. A., X-Ray Wavelengths, Rev. Mod. Phys., 39, 78–124, 1967.

  8. Bevington, P. R. and D. K. Robinson, Testing The Fit, in Data Reduction and Error Analysis for the Physical Sciences, 3rd ed., 320 pp, McGraw- Hill, New York, 2003.

  9. Binzel, R. P., A. S. Rivkin, S. J. Bus, J. M. Sunshine, and T. H. Burbine, MUSES-C target asteroid (25143) 1998 SF36: A reddened ordinary chondrite, Meteor. Planet. Sci., 36(8), 1167–1172, 2001.

  10. Chantler, C. T., K. Olsen, R. A. Dragoset, J. Chang, A. R. Kishore, S. A. Kotochigova, and D. S. Zucker, 2005, X-Ray Form Factor, Attenuation and Scattering Tables (version 2.1). [Online] Available: http://physics.nist.gov/ffast [2006, October 25]. National Institute of Standards and Technology, Gaithersburg, MD. Originally published as Chantler, C. T., J. Phys. Chem. Ref. Data, 29(4), 597–1048, 2000; and Chantler, C. T., J. Phys. Chem. Ref. Data, 24, 71–643, 1995.

  11. Clark, P. E. and J. I. Trombka, Remote X-ray spectrometry for NEAR and Future missions: Modeling and analyzing X-ray production from source to surface, J. Geophys. Res., 102(E7), 16361–16384, 1997.

  12. Demura, H., S. Kobayashi, E. Nemoto, N. Matsumoto, M. Furuya, A. Yukishita, N. Muranaka, H. Morita, K. Shirakawa, M. Maruya, H. Ohyama, M. Uo, T. Kubota, T. Hashimoto, J. Kawaguchi, A. Fujiwara, J. Saito, S. Sasaki, H. Miyamoto, and N. Hirata, Pole and Global Shape of 25143 Itokawa, Science, 312, 1347–1349, 2

  13. Feldman, U., G. A. Doschek, W. E. Behring, and K. J. H. Phillips, Electron Temperature, Emission Measure, and X-Ray Flux in A2 to X2 X-Ray Class Solar Flares, ApJ, 460, 1034–1041, 1996.

  14. Fujiwara, A., M. Abe, Y. Takagi, K. Kitazato, S. Abe, T. Hiroi, F. Vilas, B. E. Clark, P. A. Abell, S. M. Lederer, K. S. Jarvis, T. Nimura, Y. Ueda, and A. Fujiwara, Near-Infrared Spectral Results of Asteroid Itokawa from the Hayabusa Spacecraft, Science, 312, 1334–1338, 2006.

  15. GOES’s web site, http://www.sec.noaa.gov/.

  16. Hayabusa’s web site, http://hayabusa.sci.isas.jaxa.jp/.

  17. HEASARC’s web site,http://heasarc.gsfc.nasa.gov/docs/asca/gis nightearth/gis night earth.html.

  18. Ishiguro, M. I., T. H. Hiroi, D. J. T. Tholen, A. Y. Yamamoto, S. S. Sasaki, F. Y. Yoshida, B. E. Clark, R. N. Nakamura, and J. S. Saito, Detection of a Large Variation in the Degree of Space Weathering on the Surface of Itokawa by Hayabusa/AMICA Observations, LPI, 37, 1533I, 2006.

  19. Jarosewich, E., Chemical analyses of meteorites at the Smithsonian Institution: An update, M&PS, 41(9), 1271–1419, 2006.

  20. Jenkins, R., R. W. Gould, and D. Gedcke, The interaction of X-rays with Matter, in Quantitative X-ray Spectrometry 2nd Ed., edited by Brame, E. G, Jr., 504 pp., Marcel Dekker, Inc, New York·Basel·Hong Kong, 19

  21. Killen, R. M., Depletion of sulfur on the surface of asteroids and the moon, M&PS, 38(3), 383–388, 2003.

  22. Knoll, G. F., Counting Statistics and Error Prediction, in Radiation detection and measurement 3rd ed., 802 pp., Wiley, New York, 2000.

  23. Kracher, A. and D. W. G. Sears, Space weathering and the low sulfur abundance of Eros, Icarus, 174(1), 36–45, 2005.

  24. Krause, M. O., Atomic radiative and radiationless yields for K and L shells, J. Phys. Chem. Ref. Data, 8, 307–327, 1979.

  25. Lederer, S. M., D. L. Domingue, F. Vilas, M. Abe, T. L. Farnham, K. S. Jarvis, S. C. Lowry, Y. Ohba, P. R. Weissman, L. M. French, H. Fukai, S. Hasegawa, M. Ishiguro, S. M. Larson, and Y. Takagi, Physical characteristics of Hayabusa target Asteroid 25143 Itokawa, Icarus, 173(1), 153–165, 2005.

  26. Li, J., M. F. A’Hearn, and L. A. McFadden, Photometric Studies of Eros from NEAR Data, LPI, 35, 2080, 2004.

  27. Maruyama, Y., K. Ogawa, T. Okada, and M. Kato, Particle Size Effect in XRay Fluorescence and Its Implication to Planetary XRF Spectroscopy, LPI, 1338, 2007.

  28. Maslen, E. N., A. G. Fox, and M. A. O’Keefe, X-ray scattering in International Table for Crystallography, Vol. C 3rd Ed., edited by Prince, E., 1000+xxxii pp., NIST Center for Neutron Research, National Institutes of Standards and Technology, Gaithersburg, USA, 2004.

  29. Masuda, E., Master thesis of Tokyo Institute of Technology, 2002.

  30. Mewe, R., E. H. B. M. Gronenschild, and G. H. J. van den Oord, Calculated X-radiation from optically thin plasmas. V, A&AS, 62, 197–254, 1985.

  31. Michel, P. and M. Yoshikawa, Earth impact probability of the Asteroid (25143) Itokawa to be sampled by the spacecraft Hayabusa, Icarus, 179(2), 291–296, 2005.

  32. Nittler, L. R., R. D. Starr, L. Lim, T. J. McCoy, T. H. Burbine, R. C. Reedy, J. I. Trombka, P. Gorenstein, S.W. Squyres, W. V. Boynton, T. P. McClanahan, J. S. Bhangoo, P. E. Clark, M. E. Murphy, and R. Killen, X-ray fluorescence measurements of the surface elemental composition of asteroid 433 Eros, M&PS, 36(12), 1673–1695, 2001.

  33. Okada, T. and Y. Kuwada, Effect of surface roughness on X-ray fluorescence emission from planetary surfaces, LPI, 28, 1997.

  34. Okada, T., M. Kato, A. Fujimura, H. Tsunemi, and S. Kitamoto, X-ray fluorescence spectrometer onboard Muses-C, AdSpR, 25(2), 345–348, 2000.

  35. Okada, T., K. Shirai, Y. Yamamoto, T. Arai, K. Ogawa, K. Hosono, and M. Kato, X-ray Fluorescence Spectrometry of Asteroid Itokawa by Hayabusa, Science, 312, 1338–1341, 2006a.

  36. Okada, T., K. Shirai, Y. Yamamoto, T. Arai, K. Ogawa, K. Hosono, and M. Kato, Instrumentation and observations of the X-ray spectrometer onboard Hayabusa, in Advances in Geosciences, 3: Planetary Science (PS), edited by Bhardwaj, A., World Scientific, Singapore, 231–240, 2006b.

  37. Press, W. H., S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, Minimization or Maximization of Functions in Numerical Recipes in C++ 2nd Ed., edited by Press, W. H., Cambridge University Press, Cambridge, 1002 pp., 2002a.

  38. Press, W. H., S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, Modeling of Data, in Numerical Recipes in C++ 2nd Ed., edited by Press, W. H., Cambridge University Press, Cambridge, 1002 pp., 2002b.

  39. Saito, J., H. Miyamoto, R. Nakamura, M. Ishiguro, T. Michikami, A. M. Nakamura, H. Demura, S. Sasaki, N. Hirata, C. Honda, A. Yamamoto, Y. Yokota, T. Fuse, F. Yoshida, D. J. Tholen, R. W. Gaskell, T. Hashimoto, T. Kubota, Y. Higuchi, T. Nakamura, P. Smith, K. Hiraoka, T. Honda, S. Kobayashi, M. Furuya, N. Matsumoto, E. Nemoto, A. Yukishita, K. Kitazato, B. Dermawan, A. Sogame, J. Terazono, C. Shinohara, and H. Akiyama, Detailed Images of Asteroid 25143 Itokawa from Hayabusa, Science, 312, 1341–1344, 2006.

  40. Sasaki, S., J. Saito, M. Ishiguro, N. Hirata, H. Miyamoto, H. Demura, T. Hashimoto, Y. Higuchi, K. Hiraoka, C. Honda, T. Honda, K. Kitazato, T. Kubota, T. Michikami, A. M. Nakamura, R. Nakamura, T. Nakamura, P. Smith, J. Terazono, D. J. Tholen, A. Yamamoto, Y. Yokota, H. Akiyama, B. Dermawan, T. Fuse, C. Shinohara, A. Sogame, F. Yoshida, and AMICA Team, Observations of 25143 Itokawa by the Asteroid Multiband Imaging Camera (AMICA) of Hayabusa: Morphology of Brighter and Darker Areas, LPI, 37, 1325, 2

  41. Thomson, J. J., Conduction of Electricity Through Gases, 325 pp., Cambridge Univ. Press, London, 1906.

  42. Trombka, J. I., S. W. Squyres, J. Brckner, W. V. Boynton, R. C. Reedy, T. J. McCoy, P. Gorenstein, L. G. Evans, J. R. Arnold, R. D. Starr, L. R. Nittler, M. E. Murphy, I. Mikheeva, R. L. McNutt, T. P. McClanahan, E. McCartney, J. O. Goldsten, R. E. Gold, S. R. Floyd, P. E. Clark, T. H. Burbine, J. S. Bhangoo, S. H. Bailey, and M. Petaev, The Elemental Composition of Asteroid 433 Eros: Results of the NEAR-Shoemaker X-ray Spectrometer, Science, 289, 2101–2105, 2000.

  43. Yamamoto, Y., Doctor thesis of The University of Tokyo, 2002 (in Japanese).

  44. Yanai, K. and H. Kojima, Catalogue of the Antarctic Meteorites, 230 pp., National Institute of Polar Research, Tokyo, 1995.

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Correspondence to Takehiko Arai.

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Arai, T., Okada, T., Yamamoto, Y. et al. Sulfur abundance of asteroid 25143 Itokawa observed by X-ray fluorescence spectrometer onboard Hayabusa. Earth Planet Sp 60, 21–31 (2008) doi:10.1186/BF03352758

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  • Hayabusa
  • XRS
  • elemental composition
  • abundance
  • Itokawa
  • sulfur
  • space weathering