Abstract
We have evaluated the Lyman-α limb emission from the exospheric hydrogen of Mars measured by the neutral particle detector of the ASPERA-3 instrument on Mars Express in 2004 at low solar activity (solar activity index = 42, F10.7=100). We derive estimates for the hydrogen exobase density, n H = 1010 m−3, and for the apparent temperature, T > 600 K. We conclude that the limb emission measurement is dominated by a hydrogen component that is considerably hotter than the bulk temperature at the exobase. The derived values for the exosphere density and temperature are compared with similar measurements done by the Mariner space probes in the 1969. The values found with Mars Express and Mariner data are brought in a broader context of exosphere models including the possibility of having two hydrogen components in the Martian exosphere. The present observation of the Martian hydrogen exosphere is the first one at high altitudes during low solar activity, and shows that for low solar activity exospheric densities are not higher than for high solar activity.
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Anderson, D. E., and Hord, C. W.: 1971, JGR 76(28), 6666.
Anderson, D. E.: 1976, JGR 81(7), 1213.
Barabash, S., Holmström, M., Lukyanov, A., and Kallio, E.: 2002, JGR 107(A10), 1280.
Barabash, S., et al.: 2004, ASPERA-3: analyser of space plasmas and energetic ions for Mars Express, 2004mesp.book, 121.
Barth, C. A., Hord, C. W., Pearce, J. B., Kelly, K. K., Anderson, G. P., and Stewart, A. I.: 1971, JGR 76(10), 2213.
Barth, C. A., Stewart, A. I., and Hord, C. W.: 1972, Icarus 17, 457.
Bertaux, J. L.: 1978, PSS 26, 431.
Bertaux, J. L., Blamont, J., Marcelin, M., Kurt, V. G., Romanova, N. N., and Smirnov, A. S.: 1978, PSS 26, 817.
Bougher, S. W., Engel, S., Roble, R. G., and Foster, B.: 2000, JGR 105(E7), 17669.
Chaufray, J. Y., Quémerais, E., Bertaux, J. L., and Leblanc, F.: 2006, Sounding of the martian upper atmosphere with SPICAM on Mars Express, Europlanet conference 2006, abstract Nr. 00566.
Chamberlain, J. W.: 1963, PSS 11, 901.
Dementyeva, N. N., Kurt, V. G., Smirnov, A. S., Titarchuk, L. G., and Chuvahin, S. D.: 1972, Icarus 17, 475.
Deutscher, S. A., Borisov, A. G., and Sidis, V.: 1999, Phys. Rev. A 59(6), 4446.
Emerich, C., Lemaire, P., Vial, J.-C., Curdt, W., Schühle, U., and Wilhelm, K.: 2005, Icarus 178, 429.
Galli, A., Wurz, P., Barabash, S., Grigoriev, A., Gunell, H., Lundin, R., et al.: this issue, Space Sci. Rev., doi: 10.1007/s11214-006-9088-8.
Holmström, M., Barabash, S., and Kallio, E.: 2002, JGR 107(A10), 1277.
Holmström, M.: this issue, Space Sci. Rev., doi: 10.1007/s11214-006-9036-7.
Krasnopolsky, V. A., and Gladstone, G. R.: 1996, JGR 101(A7), 15765.
Krasnopolsky, V. A.: 2002, JGR 107(E12), 5128.
Krasnopolsky, V. A., and Gladstone, G. R.: 2005, Icarus 176, 395.
Lammer, H., Lichtenegger, H. I. M., Kolb, C., Ribas, I., Guinan, E. F., Abart, R., et al.: 2003, Icarus 165, 9.
Leblanc, F., Chaufray, J. Y., Lilensten, J., Witasse, and Bertaux, J.-L.: 2006, JGR 111(E9), 11.
Leinert, C., et al.: 1998, A&A Sup. Ser. 127, 1.
Lichtenegger, H. I. M., Lammer, H., and Stumptner, W.: 2002, JGR 107(A10), 1279.
Lichtenegger, H. I. M., Lammer, H., Kulikov, Yu. N., Kazeminejad, S., Molina-Cuberos, G. H., Rodrigo, R. et al.: this issue, Space Sci. Rev., doi: 10.1007/s11214-006-9082-1.
Lundin, R., Zakharov, A., Pellinen, R., Borg, H., Hultqvist, B., Pissarenko, N., et al.: 1989, Nature 341, 609.
Meier, R. R.: 1991, SSR 58, 1.
NASA: 2004, The Solar Radiation and Climate (SORCE) Experiment, http://lasp.colorado.edu/- sorce/sorce_data_access.
NASA: 2006, The Solar Wind Anisotropies (SWAN) experiment, http://sohowww.nascom.nasa.- gov/gallery/SWAN/index.html.
Nier, A. O., and McElroy, M. B.: 1977, JGR 82(28), 4341.
Thomas, G. E.: 1963, JGR 68(9), 2639.
Wurz, P., and Lammer, H.: 2003, Icarus 164, 1.
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Galli, A., Wurz, P., Lammer, H. et al. The Hydrogen Exospheric Density Profile Measured with ASPERA-3/NPD. Space Sci Rev 126, 447–467 (2006). https://doi.org/10.1007/s11214-006-9089-7
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DOI: https://doi.org/10.1007/s11214-006-9089-7