Abstract
The Apollo Solar Wind Composition (SWC) experiment was designed to measure elemental and isotopic abundances of the light noble gases in the solar wind, and to investigate time variations in the solar-wind composition. The experiment was deployed on the first five Apollo lunar landing missions. The crews exposed a foil at each of the five landing sites, and solar wind particles were collected for time periods ranging from 77 minutes in July 1969 (Apollo 11) to 45:05 hours in April 1972 (Apollo 16). The foils were returned to Earth, where the collected noble gas particles were analysed in ultra-high vacuum mass spectrometer systems. We briefly describe here the flight hardware, and the technical tests and calibrations. The experimental results were published in various scientific journals, PhD theses and NASA science reports, some of them not readily accessible after three decades. In this paper, therefore, the results obtained by the five experiments on the fluxes of the isotopes of He, Ne and Ar are summarized and discussed, so that averages and variations in solar wind composition can be more easily compared with more recent data, particularly those to be obtained by the Genesis mission. The helium flux determined for the five exposure periods varied by a factor of four, with a time-weighted average of 1.2 × 107 cm−2 s−1. Although the composition varied much less than the He-flux, definite variations were found for the 4He/3He and He/Ne ratios. The weighted average solar wind abundance ratios obtained were 4He/3He = 2350 ± 120, 4He/20Ne = 570 ± 70, 20Ne/22Ne = 13.7 ± 0.3, 22Ne/21Ne = 30 ± 3, 20Ne/36Ar = 49 ± 7 and 36Ar/38Ar =5.4 ± 0.3 (errors correspond to the 2σ level). We also measured the flow directions of individual isotopic species. We found that the lunar environment did not significantly affect the solar wind composition measured at the lunar surface, and we conclude that the SWC results are representative of the solar wind prevailing in interplanetary space at the time of the five foil exposures. Finally, we discuss, from today's perspective, some of the implications and conclusions that can be drawn from the SWC results, concerning the Sun and its history, the solar system, the galaxy and the universe.
Similar content being viewed by others
References
Alley, C. O. et al.: 1969, Apollo 11 Preliminary Science Report, NASA SP-214, 163.
ALSJ: 2003, Apollo Lunar Surface Journal, E.M. Jones (ed.), http://www.hq.nasa.gov/alsj/
Axford, W. I., Bühler, F., Chivers, H. J. A., Eberhardt, P. and Geiss, J.: 1972, J. Geophys. Res. 77, 724.
Bahcall, J. N. and Pinsonneault, M. H.: 1995, Rev. Modern Phys. 67, 781.
Balsiger, H., Altwegg, K. and Geiss, J.: 1995, J. Geophys. Res. 100, 5827.
Bame, S. J., Hundhausen, A. J., Asbridge, J. R. and Strong, I. B.: 1968, Phys. Rev. Lett. 20, 393.
Bania, T. M., Rood, R. T. and Balser, D. S.: 2002, Nature 415, 54.
Becker, R. H. and Clayton, R. N.: 1978, Geochim. Cosmochim. Acta Suppl. 10, 1619.
Benkert, J.-P., Baur, H., Signer, P. and Wieler, R.: 1993, JGR 98, 13147.
Boato, G.: 1954, Geochim. Cosmochim. Acta 6, 209.
Bochsler, P.: 1984, Helium and Oxygen in the Solar Wind, Habilitation Thesis, University of Bern, Switzerland.
Bochsler, P. and Geiss, J.: 1973, Solar Phys. 32, 3.
Bochsler, P., Geiss, J. and Maeder A.: 1990, Ŝolar Phys. 128, 203.
Bockelée-Morvan et al.: 1998, Icarus 133, 147.
Boltenkov, B. S., Gartmanov, V. N., Kocharov, G. E., Naidenov, V. O. and Starbunov, Yu. N.: 1972, Isvestia Akad. Nauk USSR, Ser. Phys. 34, 2319.
Bühler, F.: 1970, Ein Experiment zur Bestimmung der Zusammensetzung und der Isotopenverhältnisse des Sonnenwindes: I. Erste Messresultate des Sonnenwindexperiments von Apollo 11, II. Einseitige anodische Oxidierung dünner Aluminiumfolien, PhD Thesis, University of Bern, Switzerland.
Bühler, F., Eberhardt, P., Geiss, J., Meister, J. and Signer, P.: 1969, Science 166, 1502.
Bühler, F., Eberhardt, P., Geiss, J. and Schwarzmüller, J.: 1971, Earth Planet. Sci. Lett. 10, 279.
Bühler, F., Geiss, J., Meister, J., Eberhardt, P., Huneke, J.C. and Signer, P.: 1966, Earth Planet. Sci. Lett. 1, 249–255.
Bühler, F., Axford, W. I., Chivers, H. J. A. and Marti, K.: 1976, J. Geophys. Res. 81, 111.
Bühler, F., Lind, D. L., Geiss, J. and Eugster O.: 1993, in LDEF–69 months in Space, A. S. Levine (Ed.), NASA Conf. Publ. 3194(2), 705–722.
Burnett, D. S., Barraclough, B. L., Bennett, R., Neugebauer, M., Oldham, L. P., Sasaki, C. N. Sevilla, D., Smith, N., Stansbery, E., Sweetnam, D. and Wiens, R. C.: 2003, Space Sci. Rev. 105(3–4), 509.
Cerutti, H.: 1974, Die Bestimmung des Argons im Sonnenwind aus Messungen an den Apollo-SWC-Folien, PhD Thesis, University of Bern, Switzerland.
Charbonnel, C. and do Nascimento, J. D.: 1998, Astron. Astrophys. 336, 915.
Clarke, D. R., Gillette, R. B. and Beck, T. R.: 1967, Thermophysics of Spacecraft and Planetary Bodies, G. B. Heller (Ed.), Academic Press, New York-London, Progress in Astronautics and Aeronautics, 20, 315–328.
Clay, D. R., Goldstein, B. E., Neugebauer, M. and Snyder, C. W.: 1975, J. Geophys. Res. 80, 1751.
Coplan, M. A., Ogilvie, K. W., Bochsler, P. and Geiss, J.: 1984, Solar Phys. 93, 415.
Dolginov, Sh., Yeroshenko, Ye. G., Zhuzgov, L. H. and Pushkov, N. V.: 1966, Dokl. Akad. NAUK, SSSR, 170, 574.
Dyal, P., Parkin, C. W., Sonett, C. P., DuBois, R. L. and Simons, G.: 1972, Apollo 16 Preliminary Science Report, NASA SP-315, pp. 12-1-12-8.
Eberhardt, P. and Hofmann, A.: 1974, Earth Planetary Sci. Lett. 23, 304.
Eberhardt, P. Eugster, O. and Marti, K.: 1965a, Z. Naturforschg. 20a, 623.
Eberhardt, P., Geiss, J. and Grögler, N.: 1965, J. Geophys. Res. 70, 4375.
Eberhardt, P., Geiss, J., Graf, H., Grögler, N., Mendia, M. D., Mörgeli, M., Schwaller, H., Stettler, A., Krähenbühl, U. and von Gunten, H. R.: 1972, Geochim. Cosmochim. Acta Suppl. 3, 1821.
Eberhardt, P., Reber, M., Krankowsky, D. and Hodges, R. R.: 1995, Astron. Astrophys., 302, 301.
Eikenberg J., Signer P. and Wieler R.: 1993, Geochim. Cosmochim. Acta 57, 1053.
Filleux, C.: 1971, Einfangverhalten von Al2O3 für niederenergetische Edelgasionen, Master Thesis, University of Bern, Switzerland.
Filleux, C.: 1975, Häufigkeiten der Helium-und Neonisotope im Sonnenwind aus Messungen an den Apollo-SWC-Folien, PhD Thesis, University of Bern, Switzerland.
Filleux, C., Mörgeli, M., Stettler, W., Eberhardt, P. and Geiss, J.: 1980, Radiation Effects, 46, 1.
Gautier, D. and Morel, P.: 1997, Astron. Astrophys. 323, L9.
Geiss, J.: 1971, in 'Solar Wind', C. P. Sonett, P. J. Coleman, and J. M. Wilcox (eds.), Proc. Asilomar Solar Wind 2 Conf., NASA SP-308, 559.
Geiss, J. and Reeves, H.: 1981, Astron. Astrophys. 93, 189.
Geiss, J. and Reeves, H.: 1972, Astron. Astrophys. 18, 126.
Geiss, J. and Gloeckler, G.: 2003, Space Sci. Rev. 106, 3.
Geiss, J., Bühler, F., Cerutti, H., Eberhardt, P. and Filleux, C.: 1972, Apollo 16 Preliminary Science Report, NASA SP-315, p. 14–1.
Geiss, J., Eberhardt, P. and Signer, P.: 1965, Experimental determination of the solar wind composition, Proposal to NASA for Apollo Missions, S-080.
Geiss, J., Eberhardt, P., Signer, P., Bühler, F. and Meister, J.: 1969, Apollo 11 Preliminary Science Report, NASA SP-214, p. 183.
Geiss, J., Eberhardt, P., Signer, P., Bühler, F. and Meister, J.: 1970a, Apollo 12 Preliminary Science Report, NASA SP-235, 99.
Geiss, J., Eberhardt, P., Bühler, F., Meister, J. and Signer, P.: 1970b, J. Geophys. Rev. 75, 5972.
Geiss, J., Gloeckler, G. and Charbonnel, C.: 2002, Astrophys. J. 578, 862.
Geiss, J., Hirt, P. and Leutwyler, H.: 1970c, Solar Phys. 12, 458.
Geiss, J., Stettler, W. and Lind, D. L.: 1976, Helv. Phys. Acta 49, 757 (abstract).
Gerling, E. K. and Levsky, L. K.: 1956, Geochimiya, 7, 59.
Gloeckler, G. and Geiss, J.: 1996, Nature 381, 210.
Gloeckler, G. and Geiss, J.: 1998, Space Sci. Rev. 84, 275.
Gloeckler, G. and Geiss, J.: 2000, in The Light Elements and Their Evolution, L. Da Silva, M. Spite, and J. R. De Medeiros (eds.), AIU Symposium 198, p. 224.
Gloeckler, G., Geiss, J., Roelof, E. C., Fisk, L.A., Ipavich, L. M., Ogilvie, K. W., Lanzerotti, L. J., von Steiger, R. and Wilken, B.: 1994, J. Geophys. Res. 99, 17637.
Gloeckler et al.: 1999, Geophys. Res. Lett. 26, 157.
Gold, T.: 1966, in R. J. Mackin, Jr., and M. Neugebauer (eds.), The Solar Wind, Pergamon Press, 381.
Grevesse, N. and Sauval, A. J.: 1998, Space Science Rev. 85, 161.
Hess, W.N. and Calio, A.J., Apollo 11 Preliminary Science Report, NASA SP-214, 1969, p. 1
Hintenberger, H., Vilcsek, E. and Wänke, H.: 1965, Z. Naturforschung 20a, 939.
Hintenberger, H., Weber, H.W. and Takaoka, N.: 1971, Geochim. Cosmochim. Acta Suppl. 2, 1607.
Hirshberg, J., Asbridge, J. R. and Robbins, D. E.: 1971, Solar Phys. 18, 313.
Hodges, R. R., Jr., Hoffman, J. H. and Johnson, F. S.: 1974, Icarus, 21, 415.
Holweger, H.: 2001, in R. F. Wimmer-Schweingruber (ed.), Solar and Galactic Composition, AIP Conf. Proc. 598, New York, 23.
Kallenbach, R. et al.: 1997, J. Geophys. Res. 102, 26895.
Kallenbach, R., Ipavich, F. M., Kucharek, H. et al.: 1998, Space Sci. Rev. 85, 357.
Kerridge, J. F.: 1975, Science, 188, 162.
Kolodny, Y., Kerridge, J. F. and Kaplan, I. R.: 1980, Earth Planetary Sci. Lett. 46, 149.
Latham, G. V. et al.: 1969, Apollo 11 Preliminary Science Report, NASA-216, p. 143.
Lellouch, E., Bezard, B., Fouchet, T., Feuchtgruber, H., Encrenaz, T. and Graauw, T.: 2001, Astron. Astrophys. 370, 610.
Lind, D. L., Geiss, J., Bühler, F. and Eugster, O.: 1991, in LDEF — 69 Months in Space, A. S. Levine (ed.), NASA Conf. Publ. 3134(1), 585, 594.
Linsky, J. L. and Wood, B. E.: 2000, in The Light Elements and Their Evolution, L. Da Silva, M. Spite, and J. R. De Medeiros (eds.), AIU Symposium 198, pp. 141.
Mahaffy, P. R., Donahue, T. M., Atreya, S. K., Owen, T. C. and Niemann, H. B.: 1998, Space Sci. Rev. 84, 251.
Manka, R. H. and Michel, F. C.: 1971, Proc. Second Lunar Sci. Conf., vol. 2, 1717.
Marty, B., Hashizume, K., Chaussidon, M. and Wieler, R.: 2003, Space Sci. Rev. 105, 175.
Meier, R., Owen, T. C., Jewitt, D. C., Matthews, H. C., Senay, M., Biver, N., Bockelée-Morvan, D., Crovisier, J. and Gautier, D.: Science 279, 1707.
Meister, J.: 1969, Ein Experiment zur Bestimmung der Zusammensetzung und Isotopenverhältnisse des Sonnenwindes: Einfangverfahren von Aluminium für niederenergetische Edelgasionen, PhD Thesis, University of Bern, Switzerland.
Ness, N. F., Behannon, K. W., Scearce, C. S. and Cantarano, S. C.: 1967, J. Geophys. Res. 72(23), 5769.
Neugebauer M. and von Steiger, R. 2001, The Century of Space Science, J. A. M. Bleeker, J. Geiss & M. C. E. Huber (eds.), Kluwer Academic Publ. Dordrecht, 1115–1140.
NSO/SP: 2002, Sunspot Numbers, National Solar Observatory, Sacramento Peak, CA, USA.
NSSDC OMNIWeb: 2003, King, J. H. & Papitashvili, N., http://nssda.gsfc.nasa.gov/omniweb/
Ogilvie, K. W., Coplan, M. A., Bochsler, P. and Geiss, J.: 1980, J. Geophys. Res. 85, 6021.
Olive, K. A., Rood, R. T., Schramm, D. N., Truran, J. and Vangioni-Flam, E.: 1995, Astrophys. J. 444, 680.
O'Meara, J. M., Tytler, D., Kirkman, D., Suzuki, N., Prochaska, J. X., Lubin, D., and Wolfe, A. M.: 2001, Astrophys. J. 522, 718.
Owen, T., Lutz, B. L. and de Bergh, C.: 1986, Nature, 320, 244.
Owen, T., Mahaffy, P. R., Niemann, H. B., Atreya, S. and Wong, M.: 2001, Astrophys. J. 553, L77.
Owen, T. and Encrenaz, T.: 2003, Space Sci. Rev. 106, 121.
Reeves, H., Audouze, J., Fowler, W. A. and Schramm, D. N.: 1973, Astrophys. J., 179, 909.
Riordan, M. and Schramm, D. N.: 1991, The Shadows of Creation, W. H. Freeman & Co., New York.
Robert, F., Merlivat, L. and Javoy, M.: 1979, Nature 282, 785.
Robbins, D. E., Hundhausen, A. J. and Bame, S. J.: 1970, J. Geophys. Res. 75, 1178.
Salerno E., Bühler F., Bochsler P., Busemann H., Bassi M. L., Zastenker G. N., Agafonov Yu. N. and Eismont N. A.: 2003, Astrophys. J. 585, 840.
Schatzman, E. and Maeder, A.: 1981, Astron. Astrophys. 96, 1.
Schramm, D. N.: 1998, Space Sci. Rev. 84, 3.
Schwarzmüller, J.: 1970, Ein Edelgasanalysensystem mit automatischer Datenerfassung und Edelgasmessungen an Strukturelementen des Apollo-11-Mondstaubes, PhD Thesis, University of Bern, Switzerland.
Shoemaker, E. M. et al.: 1969, Apollo 11 Preliminary Science Report, NASA SP-214, p. 41.
Siscoe, G. L., Lyon, E. F., Binsack, J. H. and Bridge, H. S.: 1969, J. Geophys. Res. 74, 59.
Signer, P. and Suess, H. E.: 1963, in Earth Science and Meteoritics, J. Geiss and E.D. Goldberg (eds.), North Holland, Amsterdam, p. 241.
Signer, P., Eberhardt, P. and Geiss, J.: 1965, J. Geophys. Res. 70(9), 2243.
Signer, P., Baur, H. and Wieler, R.: 1993, Proc. Alfred O. Nier Symposium, Inorganic Mass Spectrometry, Durango, New Mexico, Los Alamos Natl. Lab. Publ. LA-12522-Los Alamos NM, 181.
Stettler, W.: 1973, Einfangverfahren von Platin für Edelgasionen mit Sonnenwindenergien, Master Thesis, University of Bern, Switzerland.
Tosi, M.: 1998, Space Sci. Rev. 84, 207.
Truran, J. W. and Cameron, A. G. W.: 1971, Astrophys. Space Sci., 14, 179.
Vauclair, S.: 1998, Space Sci. Rev. 84, 265.
von Steiger et al.: 2000, J. Geophys. Res. 105, 27217.
Wagoner, R. V., Fowler, W. A. and Hoyle, F.: 1967, Astrophys. J. 148, 3.
Walker, R., Zinner, E. and Maurette, M.: 1973, Apollo 17 Preliminary Science Report, NASA SP-330, p. 19.2.
Walker, T. P., Steigman, G., Schramm, D. N., Olive, K.A. and Kang H-S.: 1991, Astrophys. J. 376, 51.
Wänke, H.: 1965, Z. Naturforschung 20a, 946.
Wetherill, G. W.: 1954, Phys. Rev. 96, 679.
Wieler, R.: 1998, Space Sci. Rev. 85, 303.
Wieler, R. and Heber, V. S.: 2003, Space Sci. Rev. 105, 197.
Wieler, R., Baur, H. and Signer, P.: 1986, Geochim. Cosmochim. Acta, 50, 1997.
Wimmer-Schweingruber, R. F. and Bochsler, P.: 2001, in Solar and Galactic Composition, F. Wimmer-Schweingruber (ed.), AIP Conf. Proc. 598, 399.
Zastenker G. N., Salerno E., Bühler F., Bochsler P., Bassi M., Agafonov Yu. N., Eismont N. A., Khrapchenkov V. V. and Busemann, H.: 2002 Astrophysika 45, 159.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Geiss, J., Bühler, F., Cerutti, H. et al. The Apollo SWC Experiment: Results, Conclusions, Consequences. Space Science Reviews 110, 307–335 (2004). https://doi.org/10.1023/B:SPAC.0000023409.54469.40
Issue Date:
DOI: https://doi.org/10.1023/B:SPAC.0000023409.54469.40